Industrial Energy Efficiency Accelerator – Guide to the metalforming sector
Approximately 1,515GWh of energy is used each year in the UK by the metalforming sector to produce 1.3 million tonnes of metal products. This represents CO2 emissions of 450,700 tonnes. Natural gas accounts for 70% of the energy consumption. There are important differences between the energy consumption patterns of the three major sub-sectors. The forging and fasteners sub-sectors both use significant quantities of natural gas to provide process heat, whereas most sheet metal operations are cold manufacturing processes and natural gas is principally used for space heating.
Executive summary This report presents the findings and recommendations of the Investigation and Solution Identification Stage of the Industrial Energy Efficiency Accelerator (IEEA) for the Metalforming sector. The aims of this stage were to investigate energy use within the Metalforming sector-specific manufacturing processes and to provide key insights relating to opportunities for CO2 savings. Around 1.3 million tonnes of metal products are produced in the UK each year. The CO2 emissions associated with this are approximately 450,700 tonnes of CO2 per annum. Six sites were directly involved in the investigations carried out for this project. Collectively the participating sites represented about 5% of sector production. Process and energy data was collected from sub-metering installed at three sites. Overall Potential The total savings potential for the sector from the opportunities identified is difficult to quantify with confidence because a number of opportunities are mutually exclusive (i.e. implementing one may preclude another), and others target the same energy using equipment (i.e. implementing one may reduce the impact of another). Therefore the total savings available to the sector are less than the sum of the savings of individual measures. However the total savings potential avoiding duplication and interaction is thought to be in the order of 20% of the sectors current energy consumption. This would be worth circa ÂŁ11 million p.a. and reduce carbon emissions by 90,000 tonnes CO2 p.a. It should be noted that some of the opportunities can only be realised by the replacement of major plant items. The slow rate of renewal of plant within the sector represents a barrier to the uptake of these opportunities.
Metalforming Sector Overview
2
The following chart shows the relative attractiveness of the most significant core process (green) and non-core process (blue) opportunities. The majority of the savings can be achieved at a payback of less than 4 years.
The level of confidence associated with these business cases is not currently sufficient for them to form the basis of investment decisions, rather they are intended to highlight areas that Metalformers should pursue and investigate further. Next steps In the current economic climate in the UK at time of writing (March 2011), it is unlikely that funding support will be available from the Carbon Trust for demonstration of projects. Hence Metalformers are encouraged to review the opportunities highlighted, quantify these for their own sites and progress those which are considered most beneficial. Metalformers are encouraged to consider collaboration with other sector members, their supply chains and equipment and knowledge providers. Methodology The methodology used in this study included: Site visits and discussions with six host sites Gathering and analysing historical energy and process data from host sites Installation of energy sub-metering on three sites Collection and analysis of sub-meter data with process data Desk based research of potential energy efficiency opportunities and innovations A questionnaire to Metalformers on priorities, barriers, progress to date and their ideas A workshop to identify and address barriers to deployment of energy efficiency opportunities
Metalforming Sector Overview
3
Energy use within the sector 1
The Metalforming sector uses some 1,515GWh of energy each year. Natural gas accounts for 70% of the sector’s energy consumption, with electricity accounting for the remaining 30%. There are important differences between the energy consumption patterns of three major sub-sectors. The forging and fasteners sub-sectors both use significant quantities of natural gas to provide process heat, whereas most sheet metal operations are cold manufacturing processes and natural gas is principally used for space heating. Presses and hammers are used throughout the Metalforming industry and it is estimated that they account for 20% of the sector’s electricity consumption. Furnaces are used in the forging and fasteners sub-sectors both for heating of work pieces prior to hot working in a press or hammer and for heat treatment. Many furnaces, especially in the forging sub-sector, are heated by natural gas. It is estimated that furnaces account for 85% of natural gas consumption in the forging sub-sector, and 50% in the fasteners sub sector. Electrically heated furnaces and ovens are also common and it is estimated that these account for 5% of electricity consumption in the forging and fasteners sub-sectors. Carbon Saving Opportunities Significant opportunities for increased energy efficiency exist in the Metalforming sector. The main opportunities include changes to core processes such as further uptake of heat recovery, induction heating, and servo drives, as well as good practice energy management measures such as monitoring and targeting, optimisation of compressed air and behaviour change. It must be noted that not all of the opportunities are additive, as some opportunities overlap (target the same energy using process) or are mutually exclusive. Core process opportunities Furnace control systems available on the market can provide for automated system start-up, flame supervision and firing control. Energy savings are possible through reduced ‘waiting time’ prior to loading and improved control of soak time. Furnaces in the Metalforming sector reject waste heat to atmosphere using their flues. The high temperature and consistent availability of the energy in the exhaust makes it an ideal candidate for heat recovery. Two potential heat recovery opportunities are outlined: heat recovery in combustion systems using recuperators or selfrecuperative burners and heat recovery to other processes. For high volume production where all pieces are the same or similar, induction furnaces can be more energy efficient than natural gas fired furnaces. However, induction furnaces can be less flexible than natural gas fired furnaces and may be less cost effective for more bespoke products or wider product ranges. Modern efficient laser cutting systems require less electricity input in order to provide the same functionality. It 2 is claimed by the manufacturers that the overall efficiency gain of a modern laser cutting system is 17% , compared with older machines. This opportunity can only be realised when purchasing a new laser system. The energy cost reductions are not sufficient to warrant pro-active replacement of existing laser system based on energy cost savings alone. It is therefore important to consider energy efficiency at time of purchase. Recent developments in press technology use servo motors instead of a flywheel, clutch and brake. The use of servo motors to operate presses and hammers can provide reduced energy use. The cost of retrofitting a servo
1
2
Sites within the sector’s Climate Change Agreement Amada LC F1 Series 3 axis Laser Cutting Machine (company brochure)
Metalforming Sector Overview
4
drive to an existing press is almost equivalent to purchasing a new press. Therefore, this opportunity is only likely to be taken up when new presses are being purchased. It is important to ensure that loading of the furnace is optimised to gain the best efficiency. Whilst furnaces need to be heated to the correct temperature, delaying loading or poor scheduling can cause excess energy use. Better production scheduling would also help to reduce the need to run items of equipment, such as furnaces and presses, ‘in case’ they are needed, helping to improve levels of switch off during periods of no production. Where possible, outline business cases have been calculated for each the opportunities. The level of confidence associated with these business cases is not currently sufficient for them to form the basis of investment decisions, rather they are intended to highlight areas that Metalformers should pursue and investigate further. Table 1 outlines the summary business cases for each of the core-process opportunities that we have been able to quantify. For further details of the opportunities, please refer to section 5.1. Table 1 Summary of core process opportunity business cases, sector level
3
Implementation costs (£)
Saving (£ p.a.)
Saving (t CO2 p.a.)
Cost (£/t CO2)
Payback (years)
Sites applicable (%)
Automated furnace controls
£1,100,000
£460,000
3,500
£315
2.4
54%
Heat recovery in combustion systems
£4,200,000
£1, 650,000
12,200
350
2.5
54%
Heat recovery process to process
£5,100,000
£800,000
5,900
£860
6.4
54%
£4,200,000
£1,350,000
9,500
£440
3.1
54%
£0
£210,000
1,900
£0
0
31%
£300,000
£200,000
1,500
£200
1.5
54%
£0
£860,000
7,825
£0
0
100%
Opportunity
Induction heating Laser and plasma 4 cutting Production scheduling Servo drives for presses and 4 hammers
Non-core process opportunities Even the most energy efficient equipment can be operated in a wasteful manner. Appropriate levels of energy awareness and training aimed at achieving behavioural change can help ensure that at each opportunity, the most energy efficient option is chosen by the personnel involved. Compressed air is used in the sector for providing linear motion, operating valves and other applications. The compressors used are often relatively old and fitted with simple, decentralised control systems. The compressors typically vent their cooling air into the compressor room. There is scope for improvements and optimisation of compressed air systems within the sector.
3
The business cases presented in this report are based on a number of assumptions. For more details please see Table 7. This opportunity is only likely to be implemented when purchasing a new machine. It has been assumed that the purchase cost is equivalent to the less energy efficient alternative; hence the marginal cost is zero. 4
Metalforming Sector Overview
5
The Metalforming sector has a large number of Variable Speed Drives (VSDs) installed. Responses to our questionnaire indicate that, on average, respondents considered that VSDs have been installed on around 38% of suitable applications at their sites. The remaining suitable applications may benefit from addition of VSDs. It is important for sites to pre-plan the replacement significant electric motors with the highest efficiency alternative, before replacement becomes necessary. Responses to our questionnaire indicate that few sites have a formal motor management policy. If replacement with high efficiency motors is not pre-planned, there may not be sufficient time to choose a high efficiency motor when a motor fails. A significant proportion of the sector’s electricity consumption is accounted for by factory lighting. The sector would benefit from upgrading its lighting to more energy efficient lighting, such as modern T5 fluorescent fittings and lamps. It must be noted that the lifespan of T5 is adversely affected in hot operating conditions, and this should be taken into consideration when deciding where to deploy them. The Metalforming sector has some existing energy metering installed, consisting primarily of electricity and natural gas meters. Implementation of automated Monitoring and Targeting (aM&T) systems is becoming more common within the sector, but there is scope for further roll out. Voltage optimisation is thought to be viable for the majority of UK Metalforming sites, as the incoming voltage is higher than that required by the electrical equipment installed on site. Voltage optimisation equipment reduces the incoming voltage, allowing energy consumption to be reduced for certain types of electrical loads, including electric motors. Table 2 below outlines the summary business cases for each of the non-core process opportunities we have been able to quantify. For further details, please refer to section 5.2. Table 2 Summary of non-core process opportunity business cases, sector level Implementation costs (£)
Saving (£ p.a.)
Saving (t CO2 p.a.)
Cost (£/t CO2)
Payback (years)
Sites applicable (%)
£480,000
£1,100,000
9,000
£55
0.4
100%
£3,360,000
£1,050,000
9,000
£375
3.2
100%
Control of pumps and fans
£355,000
£180,000
1,600
£220
2
100%
Electrical transformers
£190,000
£115,000
1,050
£185
1.7
100%
High efficiency motors
£585,000
£460,000
4,175
140
1.3
100%
Lighting
£1,675,000
£810,000
7,350
£230
2.1
100%
Monitoring and targeting
£3,315,000
£1,700,000
15,600
£210
1.9
69%
£240,000
£415,000
3,550
£70
0.6
100%
£2,660,000
£760,000
6,900
£385
3.5
43%
Opportunity
Behaviour change Compressed air
Switch-off Voltage optimisation
5
5
The business cases presented in this report are based on a number of assumptions. For more details please see section Table 7
Metalforming Sector Overview
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Table of contents Executive summary ............................................................................................................. 1 1 Introduction .................................................................................................................... 7 2 Background to the sector .............................................................................................. 8 2.1
What is manufactured ........................................................................................................ 8
2.2
Overall scale (production, energy, carbon) ...................................................................... 14
2.3
Legislation impacts .......................................................................................................... 17
2.4
Energy saving progress ................................................................................................... 19
2.5
Business drivers............................................................................................................... 22
2.6
Energy saving drivers ...................................................................................................... 23
3 Methodology ..................................................................................................................25 3.1
Desk based research ....................................................................................................... 26
3.2
Metering and data gathering ............................................................................................ 27
3.3
Engagement with the sector ............................................................................................ 28
3.4
Understanding drivers and barriers ................................................................................. 28
4 Key findings ...................................................................................................................29 4.1
Furnace lighting & control ................................................................................................ 29
4.2
Alternative methods of off-press die heating ................................................................... 30
4.3
Alternative methods of on-press die heating ................................................................... 31
4.4
Waste heat from forging and heat treatment furnaces .................................................... 31
4.5
Efficiency of induction vs. natural gas heating ................................................................. 32
4.6
Energy consumption of laser cutting machines ............................................................... 34
4.7
Furnace load scheduling .................................................................................................. 36
4.8
Energy consumption of presses ...................................................................................... 36
4.9
Transformers.................................................................................................................... 38
4.10
Switch-off ......................................................................................................................... 40
5 Opportunities .................................................................................................................42 5.1
Core process opportunities .............................................................................................. 43
5.2
Non-core process opportunities ....................................................................................... 53
6 Next steps ......................................................................................................................64 6.1
Significant opportunities ................................................................................................... 64
Appendix 1: Indicative metering locations .......................................................................68 Appendix 2: Workshop summary information .................................................................71
Metalforming Sector Overview
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1 Introduction
This report presents the findings of the Investigation and Solution Identification Stage of the Industrial Energy Efficiency Accelerator (IEEA) for the Metalforming sector. The aims of this stage were to investigate energy use within the Metalforming sector-specific manufacturing processes and to provide key insights relating to opportunities for CO2 savings. Section 2 provides some background on the Metalforming sector in terms of what is produced, the production process, the overall scale of the sector, including energy consumption and carbon emissions, a brief summary of some key energy legislation, and identifies some key business and energy saving drivers for the sector. Section 3 outlines the methodology that was used to investigate energy use within the sector and to help identify opportunities. Section 4 outlines our key findings and briefly discusses what they might mean in terms of opportunities for the sector. Section 5 outlines the specific opportunities identified in the sector, including outline business cases where it has been possible to quantify these. Section 6 describes our recommended next steps for the opportunities identified by this project.
Metalforming Sector Overview
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2 Background to the sector
2.1
What is manufactured
The Metalforming sector produces the basic metal components that form the building blocks for other manufacturing industries. The Metalforming sector can be divided into three distinct sub-sectors: Forgings – Production of high strength parts by pressing and squeezing metal at high pressure. Forgings are used in a huge variety of safety critical and demanding engineering applications such as automotive transmission shafts and jet engine blades Sheet Metal – Production of components by pressing and cutting flat, thin pieces of metal. Example sheet metal products include various fabrications, ductwork and automotive body parts Fasteners – Production of fasteners such as bolts, similar in some respects to forging The components manufactured by the Metalforming industry usually require some form of finishing. Finishing processes include heat treatment, welding, surface cleaning, and coating. Finishing may be carried out on the same site as the Metalforming process or subcontracted out to another site.
2.1.1
Forging
Forgings are high strength parts produced when metal is pressed, pounded or squeezed at high pressure. Figure 1 shows a generic process flow diagram for the hot forging processes. Pre-heating - In the hot forging process, the metal is pre-heated in a furnace to the desired temperature (up to 1,260 ºC) before it is worked. Furnaces are usually gas fired, but may in some cases be electrically heated. Depending on the size of the piece to be forged and the required temperature, pre-heating can take many hours and represents the largest energy using process at hot forging sites. Forging - The heated metal is worked to the desired shape using presses or hammers. Presses and hammers are typically driven by hydraulic, pneumatic or mechanical flywheel systems and typically account for 20% of electrical consumption at a forging site. The dies used on presses are often heated, using either electricity or gas. Die heating may be carried out in-situ or in a separate die heater. Heat treatment - Once the metal has been worked to the desired shape, it undergoes heat treatment. This entails heating the piece in a gas or electric furnace to a specific temperature and time profile to impart the required properties e.g. softening, normalising, stress relieving, hardening. Products may undergo a number of heat treatments depending on the material and the required properties. Quenching - Depending on the heat treatment process employed, the product may be rapidly cooled in a controlled manner by quenching. In most cases quenching is carried out in an oil bath at room temperature. In a limited number of cases quenching will be carried out in a heated water bath. Tempering – Steel products may be tempered to decrease hardness and increase toughness to produce the desired combination of mechanical properties. Tempering involves heating the steel to a temperature below the transformation range and holding for a suitable time at the temperature, followed by cooling at a suitable rate.
Metalforming Sector Overview
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Machining – Machining is not considered part of the core forging process; however forging sites often include machine shops to provide rough machined or fully finished forgings. Machining operations include finishing lathes, hole boring, and milling. Surface treatment – Surface treatments such as painting or galvanising are not considered part of the core forging process and are usually carried out at another site. Figure 1 Hot forging process, with IEEA project boundary
Metalforming Sector Overview
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There are a number of different methods used to make forgings. Three of the most common methods are described below. Open die forging refers to the working of metal using dies that do not laterally confine the work piece. Metal is typically worked to the desired shape between flat-faced dies as shown in Figure 2. 6
Figure 2 Open die forging
Open-die forging comprises many process variations, permitting an extremely broad range of shapes and sizes of up to 30 meters in length and ranging from a few kilograms to many tonnes in weight. Most forgeable ferrous and non-ferrous alloys can be open-die forged, including some less common materials like age-hardening superalloys and corrosion-resistant refractory alloys. 7
Figure 3 Closed die forging
Closed die forging, also known as impression die forging, refers to the working of metal between two or more dies containing impressions of the part shape, as shown in Figure 3. Metal flow is restricted by the die contours and as a result, the process generally yields more complex shapes than open-die forging processes. This process forms forged parts that range in weight from a few grams to 25 tonnes. Metals and alloys, such as carbon and alloy steels, tool steels, aluminium and copper alloys, and certain titanium alloys can be forged by the impression-die processes.
Figure 4 Seamless rolled ring forging 8
Seamless rolled ring forging is a specific process used to produce ring shaped forgings. The process starts by punching a hole in a thick piece of metal using an open die forge forming a hollow donut shape. This donut is heated above the re-crystallization temperature and placed over the idler or mandrel roll. Under high pressure the idler roll moves towards the drive roll that continuously rotates to reduce the wall thickness, thereby increasing the diameters of the resulting ring, as shown in Figure 4.
6
Scot Forge, 2008. Open Die Forging [online] Available at: http://www.scotforge.com/sf_facts_opendie.htm [Accessed 11 November 2010]. 7 W H Tildesley, 2006. Technology [online] Available at http://www.whtildesley.com/page.asp?ID=5 [Accessed 11 November 2010]. 8 Scot Forge, 2008. Rolled Ring Forging [Online] Available at: http://www.scotforge.com/sf_facts_rollring.htm [Accessed 11 November 2010].
Metalforming Sector Overview
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This process can be used to form rings with outside diameters that vary in size from a few centimetres to over 10 meters and weights ranging from a half a kilogram up to over 160,000 kilograms. Cold Forging is similar to hot forging described above, except that the work piece is not pre-heated before working. Cold forging encompasses many processes such as bending, cold drawing, cold heading, coining, and extrusion to yield a diverse range of part shapes. Cold forgings are frequently used in automotive steering and suspension parts, antilock-braking systems, hardware and other applications where high strength, close tolerances and volume production make them an economical choice. Metals range from lower-alloy and carbon steels to 300 and 400 series stainless, selected aluminium alloys, brass and bronze.
2.1.2
Fasteners
Fasteners, such as bolts, nuts and screws are used throughout industry in areas such as aerospace and automotive engineering and construction of buildings. Fastener manufacture is similar in some respects to forging. Fasteners, such as bolts, may be manufactured using either a ‘hot’ or ‘cold’ production process. The majority of UK fastener manufacturing use cold processing techniques in which products up to 12-15mm diameter are forged in continuous forging machines (transfer headers and bolt-makers). Wire is fed at the front of the machine, and a finished or semi-finished product results after cold forging. In some cases, heat may be used on continuous forging machines and this is often provided by induction heating. Figure 5 shows a generic process flow diagram for hot process fastener manufacturing. Hot processing tends to be limited to larger diameter products (>15-30mm diameter). Cold process fastener manufacturing is similar to that described below, except that the material is not heated before being worked and is often lubricated for pressing. Pre-heating – In hot processing the metal is pre-heated to the desired temperature (up to 1,000 ºC) before pressing. A variety of heating methods are used in the fasteners sub-sector, including gas fired furnaces, electrically heated furnaces and electrical induction coils. Pressing - the work piece is inserted into the press to form the general shape of the bolt head. A second pressing finalises the head shape and this is then trimmed to remove excess material. Thread rolling - With the general shape of the bolt formed, a thread rolling machine to ‘roll’ the thread at the other end to the head. Heat treatment and Quenching - Irrespective of whether the bolts are cold or hot formed, they may require hardening by heat treatment. This is usually a bulk process where a large batch of machine finished bolts are first degreased, separated onto a conveyer, heated in an oven to 900ºC, quenched in an oil bath then tempered at 400ºC to toughen the metal. Many smaller fastener manufacturing sites in the UK do not have in-house heat treatment facilities. Tempering – Steel products may be tempered to decrease hardness and increase toughness. Tempering involves heating the steel to a temperature below the transformation range and holding for a suitable time at the temperature, followed by cooling at a suitable rate. Washing - Bolts often need to be washed in water before dispatch. The processes described above may be automated and integrated to varying degrees at different sites and on different production lines within a site. For example, the sequential stages of forming the bolt shape and thread may be carried out on separate machines or on a single integrated machine.
Metalforming Sector Overview
Figure 5 Hot process fastener manufacturing process, with IEEA project boundary
12
Metalforming Sector Overview
2.1.3
13
Sheet metal
Sheet metal is flat and thin pieces of metal that can be formed into a variety of shapes by applying force to the metal and modifying its geometry. The applied force stresses the metal beyond its yield strength, causing the material to plastically deform, but not to fail. There are a number of different sheet metalforming processes, including: Bending Roll forming Spinning Deep Drawing Stretch forming Incremental sheet forming A generalised process flow diagram for sheet metal production is shown in Figure 6. Sheet metal sites principally use electricity. Natural gas is typically only used for space heating as the vast majority of sheet metal processes are carried out cold. Painting is not considered to be part of the core sheet metal manufacturing process and has not been investigated as part of this project. However, a number of sheet metal sites incorporate paint-shops, which can be significant energy users. Figure 6 Sheet metal production process, with IEEA project boundary
Metalforming Sector Overview
2.2
14
Overall scale (production, energy, carbon)
For the purpose of this IEEA project, it has been assumed that sites within the sector Climate Change Agreement (CCA) are representative of the sector as a whole. However it should be noted that there are a number of 9 metalforming sites, particularly in the sheet metal sub-sector , that are not included within the sector CCA. Table 3 provides a summary of the energy consumption of the 96 sites within the Metalforming Climate Change 10 Agreement (CCA) for the period 2008/09 . For the analysis provided in this section, the Confederation of British 11 Metalforming (CBM) Membership directory was used to allocate sites in the CCA dataset to the three major sub-sectors. For the period 2008/09, the sector produced around 1.3 million tonnes of metal products, with associated emissions of 450,700 tonnes of CO2. Table 3 Energy consumption within the Metalforming sector 2008/09
Fasteners
Forging
Sheet metal 12
Other
Whole Sector
Natural gas consumption (GWh)
Electricity consumption (GWh)
Total (GWh)
Mean (site use)
6.4
3.2
9.5
Sub-sector Total
63.5
31.9
95.5
Mean (site use)
17.6
6.1
23.7
Sub-sector Total
738.9
255.5
994.4
Mean (site use)
4.1
3.9
7.9
Sub-sector Total
130.7
123.6
254.4
Mean (site use)
8.6
5.6
14.2
Sub-sector Total
103.5
67.3
170.8
Mean (site use)
10.8
5.0
15.8
Sub-sector Total
1,036.6
478.4
1,515.0
Both electricity and natural gas consumption are important sources of CO2 emissions in the Metalforming sector. For the sector as a whole, electricity and natural gas consumption account for around 57% and 43% of CO2 emissions respectively. Figure 7 shows that for the forging sub-sector, electricity and natural gas consumption account for roughly 50% of CO2 emissions each, whereas in the sheet metal and fasteners sub-sectors, electricity consumption accounts for 75% and 59% of CO2 emissions respectively.
9
There are approximately 24 companies in CBM Sheet Metal membership who are not in climate change agreements The most recent complete CCA dataset that could be made available to the project was 2008/09t 11 CBM (2010), Metal Matters Issue 19 12 Sites classified as ‘Other’ are within the sector CCA but could not easily be accommodated within the three major subsectors. This category includes include some sites that are not considered to be true metalformers, such as steel service centres that cut, slit and blank coil for metal forming companies. 10
Metalforming Sector Overview
15
Figure 7 CO2 emissions from electricity and natural gas consumption by sub-sector.
As discussed previously, the Metalforming sector is very diverse in terms of the products made and the processes used to make them. Therefore it is not surprising that, as shown in Figure 8, the correlation between output and energy consumption is very weak for the sector as a whole. Figure 8 also shows the relationship between output and energy consumption for sites in the three major subsectors. It can be seen that the correlation between output and energy consumption is strongest for the sheet metal sub-sector, followed by fasteners and then forging. The relationship between output and energy consumption displayed in each of the sub-sectors is indicative of the diversity of each sub-sector in terms the products made. This diversity is discussed further in the remainder of this section. Figure 8 Scatter plots showing energy consumption vs. output for plants in the Metalforming sector and three major sub-sectors
Metalforming Sector Overview
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The average Specific Energy Consumption (SEC) for the sector as a whole was 1,210kWh/tonne. Forging is the most energy intensive sub-sector (average SEC 3,517 kWh/tonne), followed by fasteners (average SEC 3,328 kWh/tonne). Forging in particular requires significant heat input as part of the core process. Heat is also required, although to a lesser extent, in the fasteners sub-sector for pre-heating larger products prior to working and heat treatment of finished products. Sheet metal is less energy intensive (average SEC 663 kWh/tonne), and heat is not usually required for the core process. Figure 9 shows that there was a wide variation in SEC in each of the three sub-sectors. In the forging and sheet metal sub-sectors, there are a small number of sites with low output and very high SEC. It is thought that these sites produce specialised products and a number may also include additional operations such as paint shops. In general, there is a weak relationship between SEC and output in the Metalforming sector. Other factors, such as the type of product being produced have a greater influence on SEC. Figure 9 Scatter plots showing SEC vs. output for plants in the Metalforming sector and three major sub-sectors
Figure 10 shows histograms of SEC for sites in the Metalforming sector and three major sub-sectors. It can be seen that there is a broad distribution in SEC in forging and fasteners sub-sectors, whereas the majority of sites in the sheet metal sub-sector have an SEC of less than 1,000 kWh/tonne.
Metalforming Sector Overview
17
Figure 10 Histograms of SEC for plants in the Metalforming sector and three major sub-sectors
The wide variation in SEC shown in both Figure 9 and Figure 10 is also indicative of diversity of each sub-sector in terms the products made. Other significant reasons for the differences in SEC between sites within subsectors observed are thought to include: Economies of scale i.e. larger sites being able to process larger batches and sites operating close to capacity making better utilisation of plant Differences in core process equipment such as furnaces and press drive systems Efficiency of energy consuming equipment (burners, motors etc.) Energy management on sites Age of plant
2.3
Legislation impacts
2.3.1
Climate Change Agreement
One of the key drivers of energy efficiency in the Metalforming sector has been the CCA, which currently covers 96 sites in the sector. The sector has had a CCA in place for ten years. Over this period the SEC for the sector as a whole has reduced by around 34%, as shown in Figure 12. From 1st April 2011 the rate of relief from CCL for all metalformers with Climate Change Agreements was reduced from 80% to 65%. In the 2011 budget it was announced by the Chancellor of the Exchequer that CCAs will be extended to 2023. It was also announced that the Climate Change Levy discount on electricity for CCA participants will be increased from 65% to 80% per cent from April 2013. The Department of Energy and Climate Change (DECC) is currently reviewing the future of the Climate Change Agreements and a consultation on proposals to simplify the agreements will be published by summer 2011.
Metalforming Sector Overview
2.3.2
18
CRC Energy Efficiency Scheme
The CRC Energy Efficiency Scheme applies to organisations that are not covered by the CCA or the EU Emissions Trading Scheme (EU ETS), but have at least one half-hourly electricity meter settled on the half-hourly market and consumed more than 6,000 MWh/year of half hourly metered electricity. The government is currently looking at simplifying the CRC Energy Efficiency Scheme. The first allowance sales for 2011-12 emissions will now take place in 2012 rather than 2011 and revenues from allowance sales to be used to support the public finances rather than being recycled to participants as originally planned. The 2011 budget confirmed that the cost of allowances under the CRC will be ÂŁ12/tonne CO2. The government will publish draft regulations to implement allowance sales in 2011. The combination of the CRC and the CCA regulations are expected to be key drivers for uptake of energy efficiency measures in the Metalforming sector over the coming years.
2.3.1
Renewable Heat Incentive
On 10 March 2011, the Government announced the details of the Renewable Heat Incentive (RHI) Scheme. The 13 Renewable Heat Incentive (RHI) is intended to provide long term support for renewable heat technologies. The scheme will make payments to those installing renewable heat technologies that qualify for support, year on year, for a fixed period of time. It is designed to cover the difference in cost between conventional fossil fuel heating and renewable heating systems. The intention is for the regulations which underpin this scheme to be approved by Parliament in summer 2011 and the scheme will be introduced shortly thereafter. Possibly of significance for the Metalforming industry is that the RHI will NOT support direct air heating from renewable sources or the recovery of waste heat from fossil fuel.
2.3.2
Carbon Price Floor
In December 2010, HM Treasury published their consultation on Carbon Price Floor. The consultation proposes removing the CCL and Fuel Duty exemptions that currently apply to electricity generators. New rates of CCL, known as carbon price support rates, will be applied to fossil fuels (other than oils) used in UK electricity generation, based upon the carbon content of the fuel. Figure 11 illustrates how the carbon price support mechanism would work. In simple terms, the carbon price support rates are additive to the prevailing EU ETS price of CO2 paid by the electricity generators.
13
www.decc.gov.uk/RHI
Metalforming Sector Overview
Figure 11 Illustration of the carbon price support mechanism
19
14
Although the proposed changes are applicable to electricity generators, it is reasonable to expect that the electricity generators will pass on the carbon price support costs to customers.
2.4
Energy saving progress
Energy costs typically represent the second largest cost to metal formers, after raw materials. The proportion of overall product cost accounted for by energy varies greatly between different products and sites, but typically accounts for between 5 and 15% of overall product cost. Nevertheless, energy costs are a strong financial driver and the Metalforming industry in the UK has a long track record of increasing its energy efficiency and reducing carbon emissions. This is evidenced by sustained reductions in specific energy consumption (SEC). Over the ten years that the sector has had a CCA in place, the SEC for the sector as a whole has reduced by around 34%. Figure 12 below shows the primary energy use per tonne produced over the period 2000-2008 and highlights the reduction in of the SEC over this time. The overall SEC reduction over the past 10 years has resulted from a combination of both efficiency improvements and changes to the mix of sites, processes and products made by the sector.
14
Source: HM Treasury, 2010
Metalforming Sector Overview
20
Figure 12 Metalforming sector energy efficiency history (primary energy)
As part of the investigations carried out for this project, a questionnaire was completed by eight metalforming sites. The questionnaire gave a list of energy efficiency measures and asked the respondent to estimate how far their company has implemented them to date. The respondents who completed the survey are responsible for metalforming plants that account for roughly 3% of the sector’s output and 15% of the sector’s energy consumption. Therefore caution must to be exercised when extrapolating these results to the sector as a whole. Figure 13 shows the average remaining potential for each of the energy efficiency measures as estimated by the questionnaire respondents. The remaining potential has been taken to be the difference between the average of the survey results for each measure and 100% implementation.
Metalforming Sector Overview
21
Figure 13 Remaining implementation potential for energy efficiency measures at metalforming sites surveyed (questionnaire results)
The survey results presented above indicate that although progress has been made and many of the standard energy management measures have been implemented to an extent, there remains significant scope for further adoption of these measures. For example very few of the respondents said that their site had implemented a motor management policy. From the survey results presented in Figure 13 it appears that the opportunities that have been implemented to the greatest degree already are often those that relate to core process energy consumption such as optimisation of furnace utilisation and automated furnace control. A number of ‘standard’ energy management measures, such as high efficiency lighting and formal motor management policies, which are typically seen as quick wins, had been implemented to a much lesser extent. This may be symptomatic of energy management falling under the responsibility of production managers. The questionnaire asked a number of questions about monitoring, targeting and reporting of energy and carbon. The responses to these questions are summaries in Figure 14. All of the companies surveyed said that they monitored their energy use and took action to reduce it. However only a quarter of the companies surveyed said they had energy efficiency targets. Public reporting of energy and carbon was even less widespread: 25% or respondents said that their company publicly reported energy use and only 1 of the companies surveyed said that they published their greenhouse gas emissions, energy efficiency or emissions reduction targets.
Metalforming Sector Overview
22
Figure 14 Monitoring, targeting and reporting of energy and carbon (questionnaire results)
2.5
Business drivers
When considering making a capital investment, metalforming companies go through a process of prioritisation and building an internal business case. The details of this process vary from one company to another, as do the required criteria for investment (payback period, IRR, NPV, etc.). The required payback period for an investment can vary from 2 to 10 years depending on the type and size of the investment, as well as other influencing factors such as compliance with regulations and customer demands. As with all businesses, there are a number of key drivers influencing decisions making. In the questionnaire we asked metalformers to rate the importance to their companies’ decision making of a range of potential drivers. Figure 15 summarises the questionnaire results for the perceptions of drivers for decision making in the metalforming companies surveyed. Figure 15 Perceptions of drivers for decision making in metalforming companies (questionnaire results)
Metalforming Sector Overview
23
The survey results shown in Figure 15 indicate that production cost, energy efficiency and customer satisfaction ranked highest in terms of their importance to company decision making. Drivers such as brand image and corporate and social responsibility (CSR) were considered to be important by roughly half of the respondents. Energy security, sustainability and water security were only considered to be important drivers by a minority of respondents.
2.6
Energy saving drivers
There are a number of factors driving moves towards energy efficiency in the sector. In the questionnaire we asked companies to identify the drivers for their energy and carbon reduction activities to date. The results are summarised in Figure 16. Figure 16 Perception of drivers for energy and carbon reduction activities by metalforming companies (questionnaire results)
The questionnaire results shown in Figure 16 indicate that energy cost is the strongest driver for energy saving activities. Other drivers such as regulation, CSR, and environmental credentials were also identified as being important. Customer pressure was only identified as a driver by one respondent. During the sector workshop, participants were asked to look in more detail at the drivers for energy efficiency within their organisations. This exercise helped to build on the insight gained from the questionnaire and provided a more detailed understanding of the specific drivers of energy efficiency in the Metalforming sector. A number of additional drivers to those shown in Figure 16 were identified by the workshop participants. These included: Process control and product quality – Equipment upgrades, such as improved burner controls, may be implemented for reasons of product quality, but may also improve energy efficiency. Independent advice – A number of examples were given where changes had been implemented following advice from independent experts such as the Carbon Trust and consultants.
Metalforming Sector Overview
24
Productivity – Changes such as increased levels of process automation are typically made with the aim of increasing productivity. However, with increased rates of throughput often comes a reduction in specific energy consumption (kWh/tonne). A summary of the information captured from the workshop, including the list of drivers for energy efficiency identified, is given in Appendix 5.
Metalforming Sector Overview
25
3 Methodology
The aim of this project was to investigate sector specific manufacturing processes in order to build a detailed picture of process energy use and identify practical, cost-effective carbon saving opportunities. Six sites were visited during Stage 1. The sites were selected to provide coverage of the three major subsectors. The sites also acted as reference points for energy efficiency opportunities to be explored with the site teams and the technical expert group. Table 4 gives some headline information on the host sites. Table 4 Headline information for the Stage 1 site visits Company
Products
Company A
Fasteners
Company B
Fasteners
Company C
Forging
Company D
Forging
Company E
Sheet Metal
Company F
Sheet Metal
Collectively, the participating sites represent around 5% of production and 12% of energy consumption for the sector. Our methodology was based on the following key elements: Project kick off meeting o
A meeting was held with the Confederation of British Metalforming (CBM) in October 2010 to reiterate the aims of the project and outline our plans, what they could expect from the accelerator and what was required of them in return.
Initial information gathering phase o
An intensive period of site visits, desk based research and consultation with the CBM to build a thorough appreciation of the sector and define the programme of work for the rest of the project.
o
A sector appreciation report was written and feedback sought from the CBM and host sites to verify that our understanding of the sector was correct, our ideas were sensible and the proposed scope of work for the main data gathering and analysis stage was feasible.
Metalforming Sector Overview
26
Main data gathering and analysis phase o
Site visits and discussions with host site personnel
o
Gathering and analysing historical energy and process data from host sites
o
Installation of energy sub-metering on three sites:
o
Collection and analysis of sub-meter data with process data
o
Desk based research potential energy efficiency opportunities
o
Desk based research of innovative opportunities in other countries and sectors that may be transferable to the UK Metalforming sector
o
A questionnaire to Metalformers on priorities, barriers, progress to date and their ideas
o
A workshop to identify and address barriers to deployment of energy efficiency opportunities
We have endeavoured to work with a representative sample of sites from the sector, including two sites from each of the major sub-sectors. However, the Metalforming sector is especially diverse in terms of products, processes, output and energy intensity. This meant that covering the full range of processes carried out within the sector was not possible within the time and budget available to the project.
3.1
Desk based research
Desk based research was carried out into energy efficient technologies that were potentially applicable to, but not necessarily already implemented in, the UK metalforming industry. The research included searches of academic literature, trade press, internet resources and case studies from Europe, the US and Asia. The findings of this research have informed the discussion of opportunities and business cases presented in Section 5 of this report. However, a brief summary of the areas considered and some useful references is provided here. The areas of research included heat recovery, furnace control, induction heating, production scheduling and alternative drives for presses and hammers. Some useful introductory material on waste heat recovery options is provided in the Good practice guide on 15 Waste Heat Recovery in The Process Industries . Further material including case studies is provided on the 16 UNEP Energy Efficiency Guide for Industry in Asia Furnace controls are used extensively within the metalforming sector, though there is certainly scope for further uptake. Case studies are available from many of the major suppliers, including Eurotherm and Rockwell Automation. Induction heating is already used within the metalforming industry; however its applicability is limited by a lack of flexibility compared with traditional furnaces. More flexible systems are now entering the market, including systems that allow sections of induction coils to be switched off and on independently, and therefore accommodating a wider range of pieces without the need to change coils. In addition, the use of high precision robotic positioning systems can help to ensure even surface heating, avoiding the need for the coils to be in contact with the surface of the component and increasing ease of use.
15
Waste Heat Recovery in The Process Industries (GPG141) http://www.carbontrust.co.uk/Publications/pages/publicationdetail.aspx?id=GPG141&respos=18&c=Industry+Energy+Efficiency &sc=Heat+Recovery&o=PublishedDate&od=asc&pn=1&ps=10 16 http://www.energyefficiencyasia.org/energyequipment/ee_ts_wasteheatrecovery.html
Metalforming Sector Overview
27
A number of specialist production scheduling tools and packages are available on the market. In addition, systems integrators often offer bespoke scheduling solutions. Any scheduling package will usually require a considerable amount of customisation to the specific site. Serveo drives are not widely used in the UK metalforming industry currently. However, the technology can readily be deployed in the industry. The main technology options are outlined in a review of the servo drive 17 technology published Metalforming . Many major suppliers of presses offer a refurbishment service during which servo drives can be retrofitted. Some major controls companies also offer retrofit drive control solutions for 18 presses
3.2
Metering and data gathering
Data from a number of sources have been used in this study to help build a picture of process energy use and quantify opportunities: Climate Change Agreement (CCA) data showing total fuel and electricity for each site within the sector Umbrella Agreement for the period 2008/09 was used to gain a sector level overview of production and energy use. Historic energy and process data from the host sites. Sub-metered energy and process data from three sites, covering: Sub-sector Forging
Processes metered Gas to a forging furnace Flue gas temperature from a forging furnace Gas to a die heater (on-press) Electricity to compressors used on a pneumatic press Electricity to a flywheel driven press Electricity to an infra-red die heater (off-press) Gas to a die heater (off-press) Gas to an upsetting furnace Electricity to a 10,000 tonne press Electricity to die heater (on-press) used on 10,000 tonne press Gas a quenching unit Electricity to heat treatment furnace (conveyor type)
Fasteners
Gas to a furnace Electricity to an induction furnace
Sheet metal Electricity to laser cutting machine Electricity to three presses of different sizes and designs
17
Osborn and Paul. Metalforming Magazine, August 2008: Servo-PressTechnology: Drive Design and Performance. http://archive.metalformingmagazine.com/2008/08/Servo_Press_Tech.pdf 18 Enrique Pano, TheFabricator.com, February 2010: Retrofitting a mechanical press with servo technology.
Metalforming Sector Overview
28
Schematic diagrams of the of the Forging, Fasteners and Sheet metal process showing indicative metering locations is given in Appendix 1. Our monitoring strategy had two main aims: 1.
To assist with the identification and confirmation and quantification of opportunities
2.
To provide insight into the energy flows through Metalforming processes.
The metering installed was considered to be the minimum required to meet these two aims and protect the anonymity of the host sites. All metering provided as part of this project is considered temporary, and will be removed at the end of the project where it is cost effective to do so.
3.3
Engagement with the sector
The Confederation of British Metalforming (CBM) were key to engaging with the sector - we are grateful to them for facilitating initial contact with host sites, distributing communications and the questionnaire and providing insight, guidance and feedback throughout the project. Throughout the project we fostered close working relationships with key contacts from the host sites. These relationships were important because the requirements made on the host sites, both in terms of time and making potentially sensitive data available for our analysis, were significant.
3.4
Understanding drivers and barriers
In addition to our meetings and discussions with the host sites and the CBM, a survey was conducted and a workshop held to help us engage with the wider sector and understand key drivers and barriers to the deployment of energy efficiency opportunities.
We received eight completed questionnaires representing eight sites. These eight sites represent approximately 3% of the sector’s output and 15% of the sector’s energy consumption. The workshop was attended by representatives from eight metalformers as well as an equipment supplier and the CBM. The format of the day was designed to be very interactive, using facilitated group exercises to make the most of the breadth and depth of knowledge and experience in the room. A summary of the information captured from the workshop is given in Appendix 5.
Metalforming Sector Overview
29
4 Key findings
This section outlines the key findings from the research and monitoring work carried out for the project and briefly discusses what they might mean in terms of opportunities for the sector. Further discussions and outline business cases for the opportunities are provided in Section 5.
4.1
Furnace lighting & control
Many furnaces in the forging and fasteners sub-sectors use natural gas as the energy source. There is always a need to allow for the furnaces to reach temperature and for the temperature to stabilise before the furnace is used. However data from some of the sites monitored for this project indicates that furnaces are sometimes lit many hours in advance of their use. In Figure 17 below, the green trace shows furnace temperature over a number of hours. Figure 17 Furnace light-up
Note. The red line is for a second furnace that was not in use at the time
It can be seen in the graph above that the furnace was lit at 01:35 on a Monday morning and gets up to working temperature by 02:30. However, information provided by the site shows that in this case, the working day did not start until 06:00. Therefore there was a ‘waiting time’ for the furnace of at least 3 hours without production. While it accepted that furnaces need time to reach temperature and for the temperature to stabilise before the furnace
Metalforming Sector Overview
30
is used, there are likely to be opportunities for energy savings through better management automatic furnace lighting. In addition to savings through improved control of light up time, modern furnace controls can also provide much better control of soak time. Time savings can be achieved by calculating the moment the work piece is uniformly at temperature, allowing for a reduction in processing time while maintaining the metallurgical integrity of the of the product. Section 5.1.1 outlines the opportunity and business case for automatic furnace lighting and control.
4.2
Alternative methods of off-press die heating
In the forging and fasteners sub-sectors, it is common to heat bolsters (die sets) in advance of their use on presses using natural gas fired ovens. This maintains the die metal at a high temperature and avoids shattering of the die when used. Figure 18 shows natural gas consumption by an off-press die heater over a period of 6 days. It can be seen that the die heater is in almost constant use over the time period. The heater shown in the graph is one of a number in use at the site and it is estimated that off-press die heaters represent around 4% of the overall the site’s gas consumption. Figure 18 Natural gas consumption by an off-press die heater
It is possible to use infra-red heaters as an alternative heating source and there is some anecdotal evidence to suggest that this can provide energy savings compared with natural gas heaters. An infra-red die heater was metered as part of this project; however the unit was not used during the monitoring period. Therefore it has not been possible to make comparisons between alternative methods of off-press die heating.
Metalforming Sector Overview
4.3
31
Alternative methods of on-press die heating
In addition to off-press die heating described in the previous section, it is also common in the forging sub-sector to heat the fixed and moving dies on presses and hammers. Again, this is to maintain the die metal at a high temperature in order to prevent them from shattering under the large forces exerted by presses and hammers. On-press dies heating may be provided by natural gas or electricity. Natural gas systems typically consist of burners supplied with a mixture of gas and air at low pressure. Electric on-press die heaters typically consist of electrical elements wrapped around the fixed or moving die and then lagged to maintain the heat on to the die metal. The advantage of electric die heaters is that, unlike natural gas systems, they are temperature controlled. It is thought that the improved controllability of electric die heaters may offer energy savings compared with natural gas systems. Metering was installed on both natural gas and electrical on-press die heaters as part of this project. However there were data quality issues with both of these meters. Therefore it has not been possible to make comparisons between alternative methods of on-press die heating. The majority of presses and hammers used on a forging site will have some form of on-press die heating installed. Therefore on-press die heating is likely to be a bigger target for energy savings than off-press heating.
4.4
Waste heat from forging and heat treatment furnaces
The furnaces in the Metalforming sector reject waste heat to atmosphere using their flues. The flue gas temperature of a furnace was measured at one of the host sites. The waste heat is rejected at a significant and sustained temperature, as is evidenced in Figure 19. Whilst the air flow through the furnace could not be established, the energy input into the furnace was measured. This data is shown in Figure 19 as the natural gas demand (in kW). Figure 19 Furnace gas consumption and exhaust temperature
Metalforming Sector Overview
32
The graph indicates that exhaust temperatures are consistently in the region of 650째C to 750째C. The energy input varies between 135kW and 220kW. It is thought that a considerable proportion of the energy input into the furnace is exhausted from the furnace using the flue. The high temperature and consistent availability of the energy in the exhaust makes it an ideal candidate for heat recovery. In addition, the sector has many furnaces, making the impact of improved heat recovery potentially significant. Sections 5.1.2 and 5.1.3 describe two potential opportunities for making use of waste heat on metalforming sites.
4.5
Efficiency of induction vs. natural gas heating
Traditionally natural gas furnaces have been used by the forging and fasteners sub-sectors to heat up the work piece before placing in the forge or hammer. Gas furnaces are often larger than required. In addition, gas traditional furnaces take time to equalise any temperature variations within the furnace before use, typically 1 to 2 hours. By contrast, induction furnaces can be switched on and off as required during the work period and do not need equalisation. Figure 20 (a) Natural gas heated furnace and (b) Electrical induction furnace
Two furnaces have been monitored at a host site, a natural gas fired furnace and an electric induction furnace. Both furnaces were used in the production of the same product. Figure 21 Energy consumption of a natural gas and an induction furnace shows the measured energy consumption of both furnaces from 05:00 to 16:00 on a particular day. Table 5 outlines the throughput of each furnace and shows the relative efficiencies of each. Figure 22 summarises the benefits of the induction furnace compared with the natural gas furnace.
Metalforming Sector Overview
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Figure 21 Energy consumption of a natural gas and an induction furnace used in the manufacture of the same product
As can be seen in Table 5, induction heating can be considerably more efficient than natural gas furnaces. Induction heating requires the induction coil to fit closely around the metal piece, therefore it is most suited to simple, high volume production, where all pieces are the same or similar. For more complex or varied production, the downtime associated with changing coils for different sized pieces may limit the cost effectiveness of induction furnaces. Table 5 Relative efficiencies of a natural gas furnace and an induction furnace used in the manufacture of the same product Natural gas furnace
Induction furnace
Energy consumption (kWh)
7,467
435
Production (pieces)
1,497
1,180
Energy use per piece (kWh/piece)
5.0
0.4
93%
kg CO2 per piece
0.9
0.2
78%
ÂŁ0.12
ÂŁ0.02
82%
Measure
Energy costs per piece
% Reduction
Metalforming Sector Overview
34
Figure 22 Summary of energy efficiency benefits of induction furnace versus a natural gas furnace
Energy savings are possible through the greater use of electrical induction heating in the forging and fasteners sub-sectors. Section 5.1.4 outlines the business case for greater use of induction heating.
4.6
Energy consumption of laser cutting machines
Laser cutting machines are normally bought for their flexibility in producing complex cuttings from large sheets of metal rather than for their energy efficiency. Figure 23 Laser cutting unit
Developments in laser technology have allowed laser cutting machines to be used in the Sheet Metal sector to cut work pieces quickly from single sheets. The process can be fully automated and can operate 24 hours/day without major operator intervention. An advantage of laser cutting is that the final product is usually very ‘clean’, meaning that little work is required to remove burrs or bad edges compared with other forms of material cutting.
Metalforming Sector Overview
35
Data has been gathered from a laser cutting machine at one of the host sites where sheet metal components for the automotive industry are manufactured. The site operates a 4kW Laser cutting machine with feeder capable of cutting sheet metal 3m x 1.5m, up to 20mm thick. The majority of the energy consumption of a laser cutting machine is not for the laser itself, but for ancillaries such as material handling, vacuum systems, compressed air and cooling. Figure 24 below shows that the 4kW laser requires up to 63kW electrical energy for operation including all ancillaries. It was not possible to monitor the electricity consumption of the laser and the ancillaries separately. However it is known that the laser is rated at 4kW. Therefore, in the graph below, the laser itself has been assumed to be operating when system demand exceeds 30kW. Figure 24 Laser energy consumption, including ancillaries
It has been claimed by one manufacturer that modern laser cutting machines can reduce energy consumption of 19 the ancillaries by up to 17% . This represents an opportunity for improvement when purchasing new laser cutting systems. This opportunity is discussed in Section 5.1.5 Figure 24 shows significant periods of very stable system electricity demand of approximately 28kW. This electricity demand is thought to be associated with the ancillary equipment of the laser cutting system, including its cooling and handling systems, during periods where the laser is not being operated i.e. the machine is idling. The electricity consumption during periods when the machine thought to be idling represented approximately 30% of the total electricity consumption during the measurement period. The electricity consumption during productive periods represented 70% of the total electricity consumption during the monitoring period. The electricity demand of the laser itself accounted for just 6% of the total measured electricity consumption of the system. Reduction the ancillary base load represents an opportunity for improvement. Switch off opportunities are discussed in more detail in Section 5.2.7.
19
Amada LC F1 Series 3 axis Laser Cutting Machine (company brochure)
Metalforming Sector Overview
4.7
36
Furnace load scheduling
Information provided by one of the host sites highlights some issues with load scheduling and points to an opportunity to improve energy efficiency. Table 6 shows information provided by the site relating to a heat treatment process. It is estimated that heat treatment accounts for 13% of the total electrical energy consumption at this site. The process is operated from Sunday evening through the Friday lunchtime with some overtime on Saturdays at times of high loading. Components are hardened or tempered in furnaces for several hours and may then be quenched in oil or water. Table 6 Load scheduling of furnace Heat-treatment
Operator’s Comments
8 November 2010
4.5 hours at 500°C
Furnace at temperature for 5 hours before loading
8 November 2010
6 hours at 475°C
Furnace ran empty at temperature for 8hours+
9 November 2010
7 hours at 465°C
OK
9 November 2010
7 hours at 465°C
Furnace ran for 12 hours after at temperature
11 November 2010
9 hours at 475°C
Furnace ran for 11 hours after at temperature
12 November 2010
9 hours at 475°C
OK
Date
The table highlights some issues with load scheduling. Often the furnace ran for many hours without any load. While it is appreciated that there will always be some delays in loading, more can be done to save energy through more efficient production scheduling. The site has estimated that energy savings of 10% in the heat treatment process area are possible through better planning and prudent operating practice. Section 5.1.6 outlines the business case for improved production scheduling.
4.8
Energy consumption of presses
There are a large number of presses used throughout the Metalforming sector. It estimated that presses and hammers account for 20% of the Metalforming sector’s electricity consumption. Traditionally, a press or hammer operates by using large vertical forces to shape the metal in a die set. The force can be supplied from a number of sources, including compressed air and hydraulic fluid. However the most common way of providing force is through the use of an electrically driven flywheel. These operate by using a motor to rotate a large flywheel, and then, when the force is required, the energy is transferred to the vertical slide of the press or hammer via a clutch to provide the downward force on the work piece. Presses or hammers of this kind require a motor, flywheel, clutch and brake to operate the system. This system allows the peaks in demand for energy to be provided by the flywheel, however, during braking there is no energy recovery. Flywheel presses also require a significant amount of maintenance and repair. A conventional 200 tonne flywheel press has been monitored at one of the host sites. Figure 25 shows the electricity demand of the press over the course of a week.
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37
Figure 25 Electricity demand of a 200 tonne flywheel press
The weekday production periods are clearly visible. Electricity demand during non-productive periods was very low. It can be seen that the press was switched off around midday on the Thursday and that it was not in use over the weekend. The electrical energy demand of a 1,600 tonne flywheel press was also measured at one of the host sites. The data is shown in Figure 26. Figure 26 Electricity demand of a 1,600 tonne flywheel press
Metalforming Sector Overview
38
The graph shows that the press spent a significant amount of time operating at low electricity demand levels, between 5 and 6kW. This is thought to be the result of the drive motor and flywheel left idling during periods of no production. Electricity consumption in these time periods accounted for 68% of total electricity consumption of the press during the measurement period. Electricity consumption during production accounted for 32% of total electricity consumption. This large electricity consumption during idling represents an opportunity for improvement through the implementation of switch off procedures and interlocks. Please refer to section 5.2.7 for further details. While it is noted that running up the flywheel does take time and the operator needs to take this into account as part of the working week, improved production scheduling would help to reduce the need run presses during periods of no production. Recent developments in press technology use servo motors instead of a flywheel, clutch and brake. The use of servo motors to operate presses and hammers can provide reduced energy use. With a servo drive, a large amount of energy is required during the accelerating cycle; however servo drives make it possible to use regenerative braking to store the energy available during the braking period. This stored energy can then be reused during the next accelerating cycle. The result is that this system can reduce the connected electrical load and smooth out the energy peaks demanded by the motor. Energy savings of 15 to 20% for servo presses compared with flywheel presses have been reported by suppliers of servo drives. For both of the presses discussed above, the electricity consumption during productive periods could be reduced by implementation of servo drives. Please refer to section 5.1.7 for further details.
4.9
Transformers
Electrical transformers are used at all sites in the Metalforming sector. An average site might have 2 or 3 transformers that provide electricity and medium voltage for site electrical distribution 415v ac. The transformers are normally supplied at a voltage of 11kV which is the normal supply voltage from the electricity company distribution system. A transformer has an operational life of 20-25 years, though it is not uncommon for them to operate for 30 years or more. A transformer is a very efficient device and will under normal full load conditions operate at an efficiency of over 96%. It is common practice to operate transformers at well below full load in order to deal with peak start-up currents as well as a means of minimising the impact of a single transformer failure. Figure 27 below shows that the efficiency drops off by a few fractions of a percentage point to 20% load and if loaded below 20% the efficiency drops of considerably. Where possible transformers should be operated at optimum load levels above 60% and this can be achieved on some sites by careful electrical load management. Where 2 or more transformers are used to supply a load, some analysis can identify good savings. Although this represents only small changes in efficiency, because the transformer will be in constant use during factory hours, good savings can be made. In addition to load management of transformers, new developments in material used to manufacture transformers can provide good savings if carefully selected. Figure 27 below shows the influence of different materials and a 0.5% efficiency improvement is possible. While this does not sound much, over the period of 20 years for over 3,000 hours a year of site operation it can represent a large saving. Therefore, when purchasing new transformers, it is important to consider lifetime costs, rather than simply initial capital costs.
Metalforming Sector Overview
Figure 27 Transformer loss curves
39
20
Figure 28 below shows the distribution of half-hourly electricity demand data for a period of two months, based on the billing data from one of the host sites (the same data is shown in a different manner is section 4.10). The xaxis shows half-hourly electricity demand as a percentage of peak electrical demand, which is assumed to be a reasonable proxy for transformer loading. This is based on the assumption that the peak electricity demand in the measurement period is similar in size to the transformer capacity, i.e. at peak electricity demand the transformer is assumed to be highly loaded. The primary y-axis shows the percentage of time that the transformer was operating at a given loading percentage. The secondary y-axis shows the transformer loss curve as a function of transformer loading percentage. It can be seen that the transformer spends a significant amount of the measurement period lowly loaded. The measurement period is not fully representative of an average year, as the measurement period contains the Christmas and New Year break. This can be clearly seen in Figure 29. Low transformer loading has a direct and negative effect on its energy efficiency, as can be seen in the relative loss graph displayed in Figure 27. For this reason it is important that the most efficient transformers are chosen at time of purchase. The transformer losses during the measurement period were approximately 16,000 kWh which represents 1.6% of the site’s electricity consumption during the measurement period.
20
The Scope for Energy Savings in the EU through the Use of Energy Efficient Electricity Distribution Transformers, EU Thermie.
Metalforming Sector Overview
40
Figure 28 Indicative transformer loading distribution graph
4.10
Switch-off
Figure 29 shows a contour graph of half-hourly electricity consumption data from the main fiscal meter of a metalforming site between 1st December 2010 and 31st January 2011. The graph shows days from left to right, time of day from top to bottom and the colours indicate the level of electricity demand during those time periods. The wide vertical dark blue band represents the shutdown period of Christmas and New Year. During this period the average electricity consumption was 47.5 kWh every half hour. This compares to a peak demand over the entire measurement period of almost 1,100 kWh per half hour. The electricity demand during the Christmas shutdown is therefore approximately 4.5% of peak demand. This is considered to be a good degree of shutdown. It can also be seen that during production weeks the night time electricity consumption is significantly higher than that during the Christmas shutdown. This is evidenced by the purple and lighter blue bands that occur before approximately 06:00 and after approximately 21:30 each day. It is also evident that switch-off at weekends is better than during weekdays, as evidenced by the purple colours as opposed to the light blue colours. These areas may represent an opportunity to improve the switch-off to the same level as seen during the Christmas shutdown period. Based on an extrapolation of the measurement period, the electricity saving could be as high as 16%. It is considered unlikely that the level of switch-off seen at Christmas can be achieved all year around, however energy savings are likely to be very viable.
Figure 29 Contour graph of half-hourly electricity consumption data
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41
Specific opportunities to reduce electrical base load through improved switch off have been noted for presses and laser cutting machines. Further discussion is provided in Section 5.2.7
Metalforming Sector Overview
42
5 Opportunities
This section outlines the opportunities identified in the sector, including outline business cases where it has been possible to quantify these. All business cases are presented on both a sector and an average site basis. The business cases have been constructed based on information from energy meters installed during the IEEA project, from process data made available by IEEA host companies, analysis of responses to the questionnaire, publicly available information and AEA’s internal expertise. References to publicly available information have been provided where possible. Table 7 below outlines the assumptions made during the calculation of the business cases. Table 7 Business case assumptions Assumption Sector annual natural gas consumption Sector annual electricity consumption
Value 1,036,586,194 kWh 478,377,345 kWh
Average natural gas price
2 p/kWh
Average electricity price
6 p/kWh
Electricity CO2 emission factor
0.545 kg CO2/kWh
Natural Gas CO2 emission factor
0.185 kg CO2/kWh
Number of sites in sector
96
Proportion of electricity consumption accounted for by presses and hammers
20%
Proportion of natural gas consumption accounted for by furnaces
Forging 85% Fasteners 50% Sheet metal 0%
Proportion of electricity consumption accounted for by furnaces
Forging 5% Fasteners 5% Sheet metal 0%
Average number of furnaces per site
Forging 5 Fasteners 5 Sheet metal 0
Metalforming Sector Overview
43
The opportunities have been grouped into two broad categories: Core process opportunities – those opportunities that are specific to metalforming processes. Some of these opportunities are quite innovative and have been implemented by the sector to a limited extent. Non-core process opportunities – these opportunities generally represent established good practice and are not specific to metalforming processes. In general, these opportunities have been partly implemented by the sector. The cost and saving numbers in the business cases have been rounded, to reflect their indicative nature. It is also important to note that several of the opportunities listed are mutually exclusive, and others target the same energy using equipment. The total savings available to the sector are therefore less than the sum of the savings of individual measures. The level of confidence associated with these business cases is not currently sufficient for them to form the basis of investment decisions, rather they are intended to highlight areas that Metalformers should pursue and investigate further. The sector emissions were 450,700 tonnes CO2 in 2008/09.
5.1
Core process opportunities
This section outlines the opportunities which are specific to the metalforming process. As these opportunities are generally more innovative than the opportunities in the next section, the level of confidence that can be applied to the costs and savings is lower, reflecting the greater uncertainties. With this in mind, the business cases have been constructed conservatively, i.e. the costs have been estimated higher and the benefits lower. Table 8 Summary table of core process opportunity business cases Implementation costs (£)
Saving (£ p.a.)
Saving (t CO2 p.a.)
Cost (£/t CO2)
Payback (years)
Sites applicable (%)
Automated furnace controls
£1,100,000
£460,000
3,500
£315
2.4
54%
Heat recovery in combustion systems
£4,200,000
£1, 650,000
12,200
350
2.5
54%
Heat recovery process to process
£5,100,000
£800,000
5,900
£860
6.4
54%
Induction heating
£4,200,000
£1,350,000
9,500
£440
3.1
54%
Laser and plasma 21 cutting
£0
£210,000
1,900
£0
0
31%
£300,000
£200,000
1,500
£200
1.5
54%
£0
£860,000
7,825
£0
0
100%
Opportunity
Production scheduling Servo drives for presses and 22 hammers
22
The opportunity is only likely to be implemented when purchasing a new machine. It has been assumed that the purchase cost is equivalent to the less energy efficient alternative; hence the marginal cost is zero
Metalforming Sector Overview
5.1.1
44
Automated furnace control
Section 4.1 outlined examples of furnaces that are, to a large extent, manually lit and controlled. Furnace control systems available on the market can provide for automated system start-up, flame supervision and firing control. Energy savings will vary from application to application but 5-10% is thought to be typical. The cost of installing furnace automation equipment ranges from £5,000 to £250,000 depending on size and complexity of furnace. The case study below gives an example of energy savings possible through furnace control.
The business case outlined below assumes the following: Combustion in furnaces represents 85% of natural gas consumption in the forging sub-sector, and 50% in the fasteners sub sector. 50% of all furnaces are already lit in an optimum manner, based on questionnaire responses. The remaining 50% of furnaces would be able to reduce their natural gas consumption by an estimated 5% by introducing automated control systems including lighting up optimisation. The average site has 5 furnaces that could benefit. The cost of a suitable controller has been estimated at £7,500 per unit. Additional costs include 10 days of internal effort per site (at £250 per day), to enable training to be carried out. Electricity consumption is reduced by 5% of the reduction in natural gas consumption, due to reduced electricity demand from furnace fans etc. Besides funding its implementation and initial training, it is thought that no significant barriers exist to increased implementation of automated furnace control.
Metalforming Sector Overview
45
Table 9 Business case for automated furnace controls Summary
Sector
Average site
Implementation costs
£1,100,000
£21,000
Cost reduction
£460,000 p.a.
£8,900 p.a.
Payback period
2.4 years
2.4 years
CO2 reduction
3,500 tonnes CO2 p.a.
65 tonnes CO2 p.a.
Sites applicable
54%
Barriers
None
Barrier mitigation
None
5.1.2
Heat recovery – Combustion systems
Many furnaces in the Metalforming sector reject waste heat to atmosphere using their flues. The high temperature and consistent availability of the energy in the exhaust makes it an ideal candidate for heat recovery. This section outlines two options for recovering heat to pre-heat combustion air. Heat Recuperation Energy can be saved by pre-heating furnace combustion air using exhaust gasses via a heat exchanger. While some companies have implemented this on large furnaces, opportunities for smaller furnaces are thought to exist. For smaller furnaces payback will be longer and therefore less attractive. Benchmark data made available to the project by a host site has shown that pre-heating combustion air using a recuperator (shown in Figure 30) enables energy savings of 10%. Figure 30 Heat recovery to combustion air using a recuperator
The figure above shows a typical heat recovery system. Heat from the furnace is allowed to heat the air to the burner chamber. The system takes air into the burner supply duct and passes this through a heat exchanger in the hot exhaust airflow system of the furnace. There is normally a combustion products clean-up system of the duct work which helps to avoid contamination of the heat exchanger and reduces emissions to atmosphere. There are other methods of heat recovery where the heat exchanger is a little more complicated but avoids the need for clean-up process.
Metalforming Sector Overview
46
Information provided to the project by one of the host sites has shown that if the combustion air can be heated to 843oC from an exhaust gas stream of 1,066oC, a recuperator of the counter-flow design described above can reduce natural gas consumption by 28%. Demonstration of this has shown simple payback of 0.2 years can be achieved. A lower temperature example, where combustion air is pre-heated to 85oC rather than ambient (32oC) reduced gas consumption by 6.2%. Pre-heated air of this temperature could be supplied from other processes such as compressed air units, which the Metalforming industry uses in large quantities. Self-Recuperating Burners Slightly different to the opportunity described above, self-recuperative burners can also provide significant energy savings. The total air supplied to the burner is split into a combustion air stream and a heat exchanger air stream. The ambient combustion air enters the burner via a single air connection on the burner housing and moves across the inside of a finned heat exchanger picking up heat from the exiting exhaust gases. The hot exhaust gases are pulled across the finned recuperator as a result of the suction pressure generated. Self-recuperating burners may be attractive for smaller furnaces (burner size of 400kW or less). The case study below gives an example of energy savings possible through the use of self-recuperative burners.
The business case outlined below assumes the following: Combustion in furnaces represents 85% of natural gas consumption in the forging sub-sector, and 50% in the fasteners sub sector.
Metalforming Sector Overview
47
50% of furnaces have heat recovery systems fitted already. The remaining furnaces could reduce natural gas consumption by 20% by fitting energy recovery to combustion air. Suitable burners can be implemented for £10,000 per burner. An average site has 5 furnaces with 4 burners each. Besides funding its implementation, it is thought that no significant barriers exist to increased implementation of heat recovery in combustion systems. Table 10 Business case for heat recovery – combustion systems Summary
Sector
Average site
Implementation costs
£4,200,000
£81,000
Cost reduction
£1,650,000p.a.
£31,750 p.a.
Payback period
2.5 years
2.5 years
CO2 reduction
12,200 tonnes CO2 p.a.
235 tonnes CO2 p.a.
Sites applicable
54%
Barriers
None
Barrier mitigation
None
5.1.3
Heat recovery – To process
In the Forging sub-sector particularly, and the Fasteners sub-sector to a lesser extent, there are potential areas for process to process heat recovery. The potential uses for waste heat will vary from one site to another – two examples are briefly described here for illustration. The first example is where furnaces are used in a heat treatment process to harden or temper a product. Following this the product is quenched in a separately heated bath of water at close to boiling point (95oC). Savings will be possible if the heat recovered from the output flue of the heat treatment furnace, or a proportion of it, can be routed through the quenching heating coil. A second potential use of waste heat is heating water used for washing and degreasing fastener products. There are likely to be a number of significant technical barriers to implementation of heat recovery from one process to another. Sites should conduct a detailed survey of heat sources and sinks to enable a robust business case to be constructed. The business case outlined below assumes the following: 3% of furnaces have such heat recovery systems implemented already. Of the remainder, it has been estimated that 75% are not suitable for heat recovery. Of the remaining suitable furnaces, it has been assumed that 20% of the energy input can be recovered to other processes. Capital costs have been estimated to be £100,000 per furnace, with 51 suitable furnaces in the sector (based on the estimated suitability outlined above, and an estimated 4 furnaces per site).
Metalforming Sector Overview
48
Table 11 Business case for heat recovery to process Summary
Sector
Average site
Implementation costs
£5,100,000
£98,000
Cost reduction
£800,000 p.a.
£15,000 p.a.
Payback period
6.4 years
6.4 years
CO2 reduction
5,900 tonnes CO2 p.a.
115 tonnes CO2 p.a.
Sites applicable
54%
Barriers
Technical. Suitable sinks must be located. Suitability includes matching the source with the sink in terms of timing of energy supply and demand, geographical location, temperature and size of energy flows.
Barrier mitigation
Each site should conduct a detailed survey of heat sources and sinks to enable a robust business case to be constructed.
5.1.4
Induction heating
An induction heater consists of a metal coil through which a medium-frequency alternating current is passed to create an oscillating magnetic field that causes eddy current heating within metal items positioned within it. For high volume production, induction furnaces can be more energy efficient than natural gas fired furnaces. Please refer to Section 4.5 for further details. The business case outlined below assumes the following: Combustion in furnaces represents 85% of natural gas consumption in the forging sub-sector, and 50% in the fasteners sub sector. Of these furnaces, 10% are potentially suitable for replacement with induction furnaces. This has been assumed to mean 21 furnaces across the sector. An induction furnace is assumed to cost £200,000 on average. The savings outlined in Section 4.5 apply.
Metalforming Sector Overview
49
Table 12 Business case for induction heating Summary
Sector
Average site
Implementation costs
£4,200,000
£80,750
Cost reduction
£1,350,000 p.a.
£26,000 p.a.
Payback period
3.1 years
3.1 years
CO2 reduction
9,500 tonnes CO2 p.a.
185 tonnes CO2 p.a.
Sites applicable
54%
Barriers
Not all products are suitable for induction heating High capital cost of induction furnace Downtime associated with changing coils for different sized products Lower flexibility compared with traditional furnaces
Barrier mitigation
5.1.5
Sites should assess whether induction heating would be suitable for them based on their product mix.
Efficient Laser cutting
Modern efficient laser cutting systems require less electricity input in order to provide the same functionality. This has mainly been achieved by improvements in the energy efficiency of the ancillary equipment, but also from improvements in the laser oscillator (laser system). The overall efficiency gain of a modern laser cutting system is 17% compared with older machines. This opportunity can only be realised when purchasing a new laser system. The energy cost reductions are not sufficient to warrant pro-active replacement of existing laser system based on energy cost savings alone. It is therefore important to consider energy efficiency at time of purchase, and the most energy efficient system should be considered. The business case outlined below assumes that a modern energy efficient laser cutting system is no more expensive than a modern low efficiency laser cutting system. Hence the marginal installation cost of the machine is assumed to be zero. In addition, the business case outlined below assumes 30 laser cutting systems in the sector and that modern systems have automated interlocks fitted which switch ancillary equipment off automatically whenever possible. The installation cost is therefore assumed to be just the expenditure required to install/program interlocks and conduct operator awareness program.
Metalforming Sector Overview
50
Table 13 Business case for efficient laser cutting Summary
Sector
Average site
Implementation costs
£0
£0
Cost reduction
£210,000 p.a.
£7,000 p.a.
Payback period
0 years
0 years
CO2 reduction
1,900 tonnes CO2 p.a.
65 tonnes CO2 p.a.
Sites applicable
31%
Barriers
Only viable when purchasing new laser cutting system.
Barrier mitigation
None
5.1.6
Improved production scheduling
Section 4.7 highlighted some issues relating to furnace loading scheduling at one site. The forging and fasteners sub-sectors use a large number of furnaces. In these process areas it is important to ensure that loading of the furnace is optimised to gain the best efficiency. Whilst furnaces need to be heated to the correct temperature, delaying loading or poor scheduling can cause excess energy use. The business case outlined below makes the following assumptions: In the forging sub-sector, furnaces account for 85% of natural gas consumption and 5% of electricity consumption. In the fasteners sub-sector, furnaces account for 50% of natural gas consumption and 5% of electricity consumption. 40 days of internal effort are required for each site to develop improved production scheduling systems. Improved load scheduling reduces energy consumption by 2%. 43% of all scheduling opportunities have already been implemented, based on questionnaire responses. Beyond the additional staff time to implement such a system, it is thought that no significant barriers exist to improved production scheduling. Table 14 Business case for improved furnace loading scheduling Summary
Sector
Average site
Implementation costs
£300,000
£5,700
Cost reduction
£200,000 p.a.
£3,800 p.a.
Payback period
1.5 years
1.5 years
CO2 reduction
1,500 tonnes CO2 p.a.
28 tonnes CO2 p.a.
Sites applicable
54%
Barriers
None
Barrier mitigation
None
Metalforming Sector Overview
5.1.7
51
Servo drives for presses and hammers
As discussed in Section 4.8, presses and hammers are used throughout the Metalforming industry and represent a significant proportion of the sector’s energy consumption. Recent developments in press technology use servo motors instead of a flywheel, clutch and brake. The use of servo motors to operate presses and hammers can provide energy savings. While the energy demand for the press stroke in both conventionally driven flywheel presses and servo motor presses is the same, the servo motor provides the option to reduce surges and gives the potential to save up to 15 to 20% energy. Figure 31 Servo Motor driven press with energy storage
The replacement of flywheel presses with servo drive presses would result in energy efficiency gains during production, as well as easier switch off during periods of no production. It is possible to retrofit a flywheel press with a servo drive system; however the cost of fitting the larger servo motor and removing the flywheel and brake is almost equivalent to purchasing a new press. Therefore, this opportunity is only likely to be taken up when new presses are being purchased. Given the low rate of introduction of new presses in the UK Metalforming sector, it is unlikely that this opportunity will be realised unless a site is purchasing a new press such as when there is redesign of production lines or as part of a company modernisation programme. However, servo drives are thought to be potentially applicable to the majority of press operations carried out in the Metalforming sector. The cost of a servo driven press is thought to be no more than a flywheel driven press. The business case outlined below makes the following assumptions: Presses and hammers represent 20% of site electricity use 15% energy savings if servo motor fitted No extra cost to fit servo motor No servo motor will be fitted unless there is a major refit at factory, i.e. the existing system is being replaced anyway. The business case therefore assumes no proactive retrofitting of this technology.
Metalforming Sector Overview
52
Table 15 Business case for servo drives for presses and hammers Summary
Sector
Average site
Implementation costs
£0
£0
Cost reduction
£860,000 p.a.
£9,000 p.a.
Payback period
0 years
0 years
CO2 reduction
7,825 tonnes CO2 p.a.
80 tonnes CO2 p.a.
Sites applicable
100%
Barriers
Low rate of press renewal within the sector.
Barrier mitigation
None
5.1.8
Core process opportunities summary
The table below outlines the advantages and disadvantages of each of the core process opportunities, including the carbon emission reduction and payback periods. Table 16 Advantages and disadvantages of the core process opportunities Opportunity Automated Furnace Control
Heat Recovery Combustion
Advantages Simple to initiate Simple to undertake High level of savings Can be implemented by site staff
Disadvantages Sustained savings difficult to achieve
may
be
Medium/high installation cost Additional maintenance Difficult to implement High installation cost
Heat Recovery Process
High savings potential
Long payback Needs high level of technical expertise Less flexible than gas furnaces
Induction Furnace
High savings potential
Not suited to most heat treatment applications Downtime for changing coils Can be technically difficult
Laser & Plasma Cutting Production Scheduling
High savings potential
High investment cost
Low implementation cost
Sustained savings difficult to achieve
High return on investment Servo Motors for Presses
Low investment (additional cost)
may
be
Only likely to be implemented at press replacement
Metalforming Sector Overview
53
Figure 32 shows the relative capital costs (x-axis) payback period (y-axis) and CO2 savings (label and diameter of bubble) for each of the core process opportunities. The level of confidence associated with these business cases is not currently sufficient for them to form the basis of investment decisions, rather they are intended to highlight areas that Metalformers should pursue and investigate further. Figure 32 Bubble chart of core process opportunities
This shows that: Heat recovery from furnace flue gasses in combustion systems offers significant carbon saving opportunities with paybacks of approximately 2.5 years. Heat recovery from process to process also offers significant carbon saving opportunities, although at longer paybacks, where technical barriers can be overcome. Induction heating represents a significant opportunity for the forging and fasteners sub-sectors. Servo drives for presses and hammers represent a significant opportunity across the metalforming sector and should be considered when presses are due to be replaced .
5.2
Non-core process opportunities
This section outlines opportunities to reduce energy costs and CO2 emissions that are considered to represent established good practice or established technology. We believe that there is significant scope for emissions savings through further dissemination and implementation of good practice within the sector. Moreover, implementation of these measures may represent the best opportunity for carbon savings in the short to medium term. The opportunities are listed here to allow the sector to gain additional insight and confidence in their potential.
Metalforming Sector Overview
54
Table 17 Summary table of non-core process opportunity business cases Implementation costs (£)
Saving (£ p.a.)
Saving (t CO2 p.a.)
Cost (£/t CO2)
Payback (years)
Sites applicable (%)
£480,000
£1,100,000
9,000
£55
0.4
100%
£3,360,000
£1,050,000
9,000
£375
3.2
100%
Control of pumps and fans
£355,000
£180,000
1,600
£220
2
100%
Electrical transformers
£190,000
£115,000
1,050
£185
1.7
100%
High efficiency motors
£585,000
£460,000
4,175
140
1.3
100%
Lighting
£1,675,000
£810,000
7,350
£230
2.1
100%
Monitoring and targeting
£3,315,000
£1,700,000
15,600
£210
1.9
69%
£240,000
£415,000
3,550
£70
0.6
100%
£2,660,000
£760,000
6,900
£385
3.5
43%
Opportunity
Behaviour change Compressed air
Switch-off Voltage optimisation
5.2.1
Behaviour change
Even the most energy efficient equipment can be operated in a wasteful manner. Appropriate levels of energy awareness and training aimed at achieving behavioural change is key to addressing these opportunities. This will help ensure that at each opportunity the most energy efficient option is chosen by the personnel involved. A training programme would include the following elements: Identification of target audiences, such as energy specialists, operational staff, technical staff, financial decision makers, design staff, specifiers or procurement staff. Identification of training needs for each of the audiences. Design of a structured programme to address the gap between the current situation and the desired outcomes. Continuous delivery of training. Review of the effectiveness and efficiency of the training programme. The business case outlined below is based on 20 days internal effort per site, and a 2% reduction in energy consumption. It must be noted that the effort must be repeated regularly (potentially annually) in order for the training to remain effective. The reduction in energy consumption occurs as people modify their behaviour to become more efficient. This may take the form of suggestions to improve operations or throughput, increased use of energy information in decision making, switching equipment off when possible, etc. No significant barriers are thought to exist for the implementation of behaviour change.
Metalforming Sector Overview
55
Table 18 Business case for Behaviour change Summary
Sector
Average site
Implementation costs
£480,000
£5,000
Cost reduction
£1,090,000 p.a.
£11,350 p.a.
Payback period
0.4 years
0.4 years
CO2 reduction
9,050 tonnes CO2 p.a.
94 Tonnes CO2 p.a.
Sites applicable
100%
Barriers
None
Barrier mitigation
None
5.2.2
Compressed air management
Compressed air is used in the sector for providing linear motion, operating valves and other applications. The compressors used are often relatively old and fitted with simple, decentralised control systems. The compressors typically vent their cooling air into the compressor room. Several opportunities have been observed which each may reduce energy consumption. These include: Heat recovery from compressor cooling. Compressed air leak detection and repair. Replacement of old fixed speed compressors with modern high efficiency, variable speed units. Compressed air generation pressure reduction. Centralised computerised control system for systems with multiple compressors. Using electrical alternatives to compressed air consumers, where it is safe and viable to do so. All the above opportunities will reduce the energy consumption of the compressors, whilst maintaining the same level of functionality. The business case outlined below illustrates the benefits of this opportunity and it is based on the following assumptions: 50% of sites have optimised their compressed air systems already, based on questionnaire responses At the remaining 50% of sites, savings are based on the implementation of heat recovery, VSD compressors and further optimisation such as leak detection and pressure reduction. Average site compressor rating of 150kW, fixed speed machines. 30% of heat generated can be used to displace other heat. 50% of compressors can benefit from VSD technology, and these gain a 15% improvement in energy efficiency. 10% energy efficiency gain due to optimisation Besides funding its implementation, it is thought that no significant barriers exist to the deployment of compressed air optimisation in the sector.
Metalforming Sector Overview
56
Table 19 Business case for compressed air management Summary
Sector
Average site
Implementation costs
£3,360,000
£35,000
Cost reduction
£1,050,000 p.a.
£11,000 p.a.
Payback period
3.2 years
3.2 years
CO2 reduction
9,000 tonnes CO2 p.a.
95 tonnes CO2 p.a.
Sites applicable
100%
Barriers
None
Barrier mitigation
None
References
http://www.carbontrust.co.uk/publications/pages/home.aspx
5.2.3
Control of pumps and fans
Pumps and fans, particularly centrifugal models, benefit from precise control of their speed in order to balance performance and energy efficiency. Such precise control can be achieved by the installation of a Variable Speed Drive (VSD) onto the motor driving the centrifugal pump or fan. For optimum results, the VSD is often controlled by a pressure transducer in the suction pipe (for extraction systems) or the pressure pipe. VSDs allow electric motors to run at speeds other than their nominal speed. This is achieved by altering the frequency of the alternating current supplied to the motor. Energy savings result from the electric motor being able to better match the supply of energy with the demand for energy. The Metalforming sector has a large number of variable speed drives installed, though the driving factor for this has often been improved process control rather than energy savings. Responses to our questionnaire indicate that, on average, respondents considered that VSDs have been installed on around 38% of suitable applications at their sites. Examples include combustion air fans and extraction systems. Regardless of the driving factor, energy savings will result from the installation of variable speed drive on the majority of applications. The business case summary below is based on the following assumptions: 5% of the sector’s electricity demand is used by centrifugal pumps and fans. 38% of those already have VSDs installed. An average saving of 20% can be achieved on the remaining applications. Costs have been based on an average motor size of 22kW for pumps and fans. Besides funding implementation, it is thought that no significant barriers exist to the deployment of VSDs in the sector.
Metalforming Sector Overview
57
Table 20 Business case for control of pumps and fans Summary
Sector
Average site
Implementation costs
£355,000
£3,700
Cost reduction
£180,000 p.a.
£1,850 p.a.
Payback period
2 years
2 years
CO2 reduction
1,625 tonnes CO2 p.a.
17 tonnes CO2 p.a.
Sites applicable
100%
Barriers
None
Barrier mitigation
None
References
http://www.carbontrust.co.uk/publications/pages/home.aspx
5.2.4
High efficiency motors
The efficiency of electric motors is defined as the ratio of shaft power to the input power. Most modern electric motors are already quite efficient, with efficiencies between 90 and 95% being common. Responses to our questionnaire indicate that, on average, respondents considered that high efficiency motors have been installed on around 34% of suitable applications at their sites. Given the high price and carbon intensity of electricity, and typically a high annual utilisation of electric motors, further roll out of high efficiency motors should be pursued. It is considered likely that the majority of electric motors do not warrant pro-active replacement based on the energy cost savings alone. Hence this opportunity should be taken forward when electric motors are due for replacement. It is therefore important that sites pre-plan the replacement for each significant electric motor with the highest efficiency alternative before replacement becomes necessary. Responses to our questionnaire indicate that few sites have a formal motor management policy. If replacement with a high efficiency motor isn’t pre-planned, there may not be sufficient time to choose a high efficiency motor when a motor fails. The business case outlined below assumes the following: Implementation costs cover the marginal cost of replacement only (i.e. the additional cost of a high efficiency motor over a standard motor). 34% of all suitable motors are high efficiency already, according to questionnaire responses. The efficiency of the remaining 66% is assumed to improve by 4%. Energy efficient motors are assumed to cost 25% more than standard motors. Savings are based on an extrapolation of a 22 kW motor operating 4,000 hours per year.
Metalforming Sector Overview
58
Table 21 Business case for high efficiency motors
5.2.5
Summary
Sector
Average site
Implementation costs
£585,000
£6,100
Cost reduction
£460,000 p.a.
£4,800 p.a.
Payback period
1.3 years
1.3 years
CO2 reduction
4,200 tonnes CO2 p.a.
45 tonnes CO2 p.a.
Sites applicable
100%
Barriers
Urgency of replacement when a motor fails.
Barrier mitigation
Pre-planning replacement of large motors.
References
http://www.carbontrust.co.uk/publications/pages/home.aspx
High efficiency lighting
A significant proportion of the sector’s electricity consumption is accounted for by lighting. The types of lighting in use are primarily Metal Halide and fluorescent and also include High Pressure Sodium and halogen. The sector would benefit from upgrading its lighting to more energy efficient lighting, such as modern T5 fluorescent fittings and lamps. These lamps have long average lives, low running costs, low lumens depreciation (deterioration of light output over the lamps life) and offer a high degree of controllability. This would enable daylight dimming and/or occupancy detection controls to operate the lighting which would result in further energy savings. Improved controllability has not been taken into account in the business case below. It must be noted that the lifespan of T5 is adversely affected in hot operating conditions, and this should be taken into consideration when deciding where to deploy them. Site specific advice should be sought from the supplier. The business case outlined below is based on the following assumptions: 6% of the sector’s electricity consumption is used for lighting Existing lighting consists of 70% metal halide lamps, 25% T8 fluorescent lamps and 5% T5 fluorescent lamps. Full replacement with T5 lighting would increase energy efficiency by 58% for metal halide lamps and 50% for T8 fluorescent lamps. Lights are assumed to be on 16 hours per day, 350 days per year. Installation costs are 50% of the capital costs of the fittings and lamps.
It is thought that no significant barriers exist to the installation of further high efficiency lighting in the sector.
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59
Table 22 Business case for high efficiency lighting
5.2.6
Summary
Sector
Average site
Implementation costs
£1,680,000
£17,500
Cost reduction
£810,000 p.a.
£8,400 p.a.
Payback period
2.1 years
2.1 years
CO2 reduction
7,350 tonnes CO2 p.a.
77 tonnes CO2 p.a.
Sites applicable
100%
Barriers
None
Barrier mitigation
None
References
http://www.carbontrust.co.uk/publications/pages/home.aspx
Automated Monitoring and Targeting
Automated Monitoring and Targeting (aM&T) systems enable improved management of energy use, including the highlighting of wasteful consumption patterns. aM&T systems consist of energy meters for each of the major process at a site, local data storage using a data logger as well as analysis software. aM&T systems can typically deliver savings of 5-10% of energy costs, but only if the data they collect is analysed and acted upon. aM&T systems are at their most useful when the energy data is correlated with ‘drivers’, i.e. the key variables which affect energy consumption. These typically include production throughput, operating temperatures, operating hours, etc. The business case outlined below is based on the following assumptions: At an average site 31% of aM&T opportunities have been implemented already, based on questionnaire responses. Average savings of 5% has been assumed for all utilities. Besides funding implementation, it is thought that no significant barriers exist to the deployment of aM&T systems in the sector. Table 23 Business case for monitoring and targeting Summary
Sector
Average site
Implementation costs
£3,315,000
£50,000
Cost reduction
£1,700,000 p.a.
£25,750 p.a.
Payback period
1.9 years
1.9 years
CO2 reduction
15,600 tonnes CO2 p.a.
235 tonnes CO2 p.a.
Sites applicable
69%
Barriers
None
Barrier mitigation
None
References
http://www.carbontrust.co.uk/publications/pages/home.aspx
Metalforming Sector Overview
5.2.7
60
Switch off
During the site visits it was observed that several pieces of equipment where left idling during periods of no production. As energy is still consumed during idling, ensuring that all equipment is switch off where practical and safe to do so, will result in energy savings. The degree of switch off achieved by sites is discussed in section 4.10. One way of improving the degree of switch-off is to implement a formal switch-off routine or procedure. This could take the form of a map highlighting major pieces of equipment together with their controls. Each control could be marked according to a traffic light system where red represents equipment which must be left running, yellow may represent equipment that can be switch-off over 1 hours idling and green may represent equipment that can be switched off the moment the operator leaves the machine. Formal responsibility for switching equipment of should be part of job specifications and reinforced in training. All staff should be aware of their responsibility and ability to switch equipment off. Once a formal switch-off procedure is implemented its effectiveness should be reviewed regularly. This could be done by conducting an out-of-hours survey. The business case below is based on the following assumptions: 10 days of internal effort per site to formalise a switch-off procedure 1% reduction in electricity consumption and a 0.5% reduction in natural gas consumption as a result It is thought that no significant barriers exist to the deployment of switch-off procedures in the sector. Table 24 Business case for switch off Summary
Sector
Average site
Implementation costs
£240,000
£2,500
Cost reduction
£415,000 p.a.
£4,300 p.a.
Payback period
0.6 Years
0.6 years
CO2 reduction
3,550 tonnes CO2 p.a.
37 tonnes CO2 p.a.
Sites applicable
100%
Barriers
Awareness of what can be switched off.
Barrier mitigation
Training. Formal switch off procedure.
5.2.8
Electrical transformers
Electricity cost reductions can be achieved by the installation of highly energy efficient transformers. Whilst existing transformers will have reasonably high efficiency already, it is recommended that energy efficiency is given prime consideration during transformer replacement. This is important as all electricity supplied via the transformer will be affected by it efficiency. In addition transformers typically have a long life, and they should therefore be assessed on a lowest lifetime cost basis. The business case outlined below assumes the following: Average transformer efficiency gain of 0.4% resulting in 0.4% reduction in electricity consumption.
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The marginal cost of a high efficiency transformer (i.e. the additional cost over and above a standard transformer) is assumed to be £1,000 per transformer. Each site has an average of 2 transformers. All sites in the sector own their transformers and are therefore able to control the specifications and energy efficiency at replacement stage. A significant barrier to the deployment of this opportunity is the slow rate of replacement of existing transformers. Properly maintained a transformer has a life expectancy exceeding 20 years. Assuming an average life of 25 years for each transformer, the sector would only replace an average of 8 transformers each year. Table 25 Business case for electrical transformers Summary
Sector
Average site
Implementation costs
£192,000
£2,000
Cost reduction
£115,000 p.a.
£1,200 p.a.
Payback period
1.7 years
1.7 years
CO2 reduction
1,050 tonnes CO2 p.a.
11 tonnes CO2 p.a.
Sites applicable
100%
Barriers
Low replacement rate leading to low rate of improvement in energy efficiency.
Barrier mitigation
None
5.2.9
Voltage optimisation
Voltage optimisation equipment reduces the voltage of the incoming supply to a site. This is viable for the majority of UK sites, as the incoming voltage is higher than that required by the electrical equipment installed on site. By reducing the voltage, energy consumption can be reduced for certain types of electrical loads, including electric motors. Responses to our questionnaire indicate that, on average, respondents considered that around 39% the potential for voltage optimisation had already been implemented at their sites, which may include tapping down owned transformers. The business case summary below assumes the following: Voltage optimisation is possible at 70% of the remaining sites in the sector 62% of all electrical equipment at those sites will show a saving due to voltage optimisation That equipment will show an average electricity cost saving of 10% A site specific survey should be carried out by a reputable supplier in each case before a decision to progress is taken. The survey should include the measurement of the site voltage at the furthest distribution point (to account for voltage drop across the site) for an extended period of time, as well as a thorough site survey to assess the types and populations of electrical equipment in use. All these factors influence the energy saving potential for the site. It is considered that there are no significant barriers to the implementation of voltage optimisation, beyond the need to fund the improvement. The site electricity supply will need to be de-energised during the installation of the equipment. It is thought this can be achieved with appropriate planning.
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Table 26 Business case for voltage optimisation Summary
Sector
Average site
Implementation costs
£2,260,000
£65,000
Cost reduction
£760,000 p.a.
£18,500 p.a.
Payback period
3.5 years
3.5 years
CO2 reduction
6,900 tonnes CO2 p.a.
170 tonnes CO2 p.a.
Sites applicable
43%
Barriers
None, though implementation requires scheduling.
Barrier mitigation
None
5.2.10 Summary The table below outlines the advantages and disadvantages of each of the non-core process opportunities. Table 27 Non-core process opportunities summary Opportunity
Advantages
Disadvantages
Behaviour change
Low cost, low risk In-house implementation
Effectiveness decreases requires repetition
Compressed air
Established energy saving technique
Leak management is ongoing routine
over
time,
Fast pay back periods for some measures Control of pumps and fans
Established energy saving technique
High efficiency motors
Established energy saving technique
Likely to be only cost effective when existing motors are being replaced
Lighting
Established energy saving technique
Not all high efficiency lighting may be suitable for high temperature environments
Typically easily implemented
Allows for improved controllability, potentially offering further savings Monitoring and targeting
Established energy saving technique Large benefits can be gained
Savings cannot always accurately beforehand
be
predicted
Lighting output can degrade rapidly in dusty environments Savings will only be achieved if the information provided is acted on Metering can be difficult to get right
Switch-off
Low cost, low risk In-house implementation
Voltage optimisation
Established energy saving technique
Effectiveness decreases requires repetition
over
time,
Longer payback period than other good practice measures Not suitable for all equipment, including some electrical furnaces
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The following chart shows the relative capital costs (x-axis) payback period (y-axis) and CO2 savings (label and diameter of bubble) for each of the non-core process opportunities. Figure 33 Bubble chart of non-core process opportunities
This shows that: Monitoring and targeting and behaviour change represent significant opportunities with relatively low costs, short payback and significant CO2 savings. Individually, smaller measures with low capital costs offer a fast return, and cumulatively represent a significant opportunity. Voltage optimisation and compressed air management are the only non-core process measures with a payback period higher than 2.5 years.
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6 Next steps
This section describes our recommended next steps for the significant opportunities (larger than 7,500 tonnes CO2 p.a. sector-scale emissions reduction) discussed in Section 5.
6.1
Significant opportunities
Table 28 and Figure 34 below outline the significant opportunities, together with their estimated capital investment, payback period and CO2 savings. The level of confidence associated with these business cases is not currently sufficient for them to form the basis of investment decisions, rather they are intended to highlight areas that Metalformers should pursue and investigate further. Table 28 Significant opportunities
Opportunity
Capex
Payback
CO2 Savings
Heat recovery in combustion systems
£4,200,000
2.5
12,200
Induction heating
£4,200,000
3.1
9,500
£0
0
7,825
Compressed air
£3,360,000
3.2
9,000
Monitoring and targeting
£3,315,000
1.9
15,600
£480,000
0.4
9,000
Servo drives for presses and hammers
Behaviour change
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Figure 34 Bubble chart of the most significant opportunities
Following the completion of the investigation stage of the IEEA project, individual Metalformers and the CBM are encouraged to review the opportunities and their business cases and decide which opportunities are the highest priorities for their sites, companies and the sector. Consideration should be given to collaboration with academia and equipment or knowledge providers. In the current economic climate in the UK at time of writing (March 2011), it is unlikely that funding support will be available from the Carbon Trust for demonstration of projects. The majority of the opportunities discussed in this report are considered to be relatively mature and do not require significant R&D to build confidence. It is thought that suppliers can be identified and suitable systems can be designed and priced. In all cases, the opportunities should be considered at times when major capital projects such as re-fits are being planned. Including innovation within major capital projects is likely to reduce their capital costs as inclusion in design is typically cheaper than retrofit. In summary, Metalformers are encouraged to: 1.
Consider which opportunities they can take forward themselves
2.
Consider which opportunities may require collaboration with other CBM members, the CBM itself, the supply chain, equipment or knowledge providers
3.
Confirm the development needs for each opportunity
4.
Conduct any necessary R&D work, potentially in collaboration with others
5.
Implement a pilot project
6.
Roll-out once sufficient confidence has been developed
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Acknowledgements The Confederation of British Metalforming (CBM) were key to engaging with the sector - we are grateful to them for facilitating initial contact with host sites, distributing communications and the questionnaire and providing insight, guidance and feedback throughout the project. AEA are also grateful to the host sites for providing access to their sites and sharing process and energy data with the project. AEA also wishes to thank all individuals who assisted us throughout this project.
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Appendices Appendix 1: Indicative metering locations Appendix 2: Workshop summary
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Metalforming Sector Overview
Appendix 1: Indicative metering locations Figure 35 Forging process - Indicative metering locations
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Figure 1 Fastener manufacturing process – indicative metering locations
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Figure 2 Sheet metal process – indicative metering locations
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Appendix 2: Workshop summary information A workshop hosted by CBM was held on the 22nd February. The aims of the workshop were to present the opportunities that the AEA team had identified to date and to discuss the specific drivers and barriers surrounding the implementation of these opportunities. The workshop started with an overview of the programme by Al-Karim Govindji of the Carbon Trust and a presentation from CBM by Ken Campbell on the significant challenges that the sector faces in terms of climate change and reducing CO2 emissions. An update on the site visits was then provided by Mike Birks and Jan Bastiaans of AEA. After a discussion about which of the opportunities the organisations present had implemented to date, the group went through a three stage brainstorming process. The first stage considered the opportunities presented and what was missing from the list. A long list was drawn up which contained both standard energy management ideas such as energy efficient lighting, but also experience shared of interventions that the organisations had already implemented or were aware of. The list of opportunities drawn up at the sector workshop is presented in the table below. Table 1 Opportunities identified at sector workshop Opportunity heading Improved production planning
Specific opportunities Better utilisation of plant (furnaces, presses, paint shops) Only heating material that will then be used Use correct press for the job (avoid using large presses for small jobs) Use correct furnace for the job (avoid using large furnaces for small jobs)
Induction heating
Control of induction heat core temperatures Increased flexibility of induction heating
Use of Servo drives on presses
Retro-fit of servo drives to flywheel presses Replacement of existing press drive systems (flywheel, hydraulic, pneumatic) with servo drives
Improved burner controls
Pulse fired burners for furnaces Improved control of gas fired die heaters Replacement of uncontrolled gas fired die heaters with infrared die heaters
Improved process control of furnaces
Defining the optimum light up time for every furnace (avoid unnecessary unloaded running)
Heat recovery
Heat recovery within process to improve combustion efficiency Heat recovery to another process (e.g. quench or metal washing) Heat recovery to space heating Heat recovery to electricity generation (ORC)
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Compressed air heat recovery Improved management of compressed air
Compressed air leak detection and maintenance VSD compressors Zoning of compressed air Use separate compressors for certain plant e.g. laser cutting machine Reduce pressure (where appropriate) Turn off compressor when not needed
More efficient factory lighting
Energy efficient lights Presence detection for lighting Solar controls for lighting
AMR, Smart metering, sub-metering
Metering and Targeting
More efficient factory heating
Use waste heat from furnaces and compressed air for factory space eating Improved factory insulation Zoning of heating for different areas of the workshop
Maintaining 0.95 Power Factor without Power Factor correction capacitors Voltage optimisation by tapping down transformers Extraction control and switch off
VSD extraction Interlock' - link extraction to process
Improved furnace insulation Automatic doors on furnaces Ask gas supplier to boost the pressure, allowing the gas booster to do less work or be switched off completely, resulting in electricity savings. Planned maintenance of machines and tools (rather than just reactive) Employee awareness
Target maintenance staff with making energy savings
Reduce peak demand: reduce capacity charge; reduce pressure on electricity grid
Encourage businesses to manufacture outside of 'normal hours' Stagger MCC start-up times
Rationalisation of product range: fewer changeovers, longer production runs Strategic 'make or buy' decisions Working from home for admin staff
Subcontracting non-core processes that could be more efficiently done by others
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The second stage of the brainstorming process considered the drivers and barriers to the opportunities presented. The table below lists the drivers for energy efficiency identified at the workshop and, where appropriate, the specific opportunities they are applicable to. Table 2 Drivers for energy efficiency identified at sector workshop Drivers Product Quality
Opportunities applicable to Improved production planning Induction heating Improved burner controls Improved process control of furnaces
Smaller batch sizes
Induction heating
Process control improvements
Induction heating Use of Servo drives on presses Improved burner controls Improved process control of furnaces
Expert advice (Carbon Trust, Consultants, Suppliers, CBM)
Improved burner controls
Co-location of heat requiring processes
Heat recovery
Cost savings
All
Increasing energy prices
All
Senior management drive
All
Legislation - CCA, CRC etc.
All
Company standards
All
Competition - product quality and cost
All
Speeding up process
All
Customer driven accreditation e.g. ISO14001
All
Resource depletion
All
Waste reduction activities
All
The third stage of the brainstorming process considered who could influence the barriers to drive them into solutions. The barriers, influencers and potential solutions are presented in the table below.
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Table 3 Influencers and potential solutions to barriers identified at the sector workshop Barrier Inertia to change
Opportunities applicable to All
Influencers Metalformers
Potential Solutions Training / bring in new people
Carbon Trust Ability to raise finance
All
Government
Soft loans, grants and taxes Encourage stability in markets and encourage banks to lend
Banks (loans)
Provide finance at reasonable rates
Metalformers
Metalformers to build long term relationships with customers and suppliers (co-financing, spread costs?)
Metalformers to build capital availability into business plans
Capital cost
Induction heating
Carbon Trust
Expand ECA to cover more good practice technologies
Government
Soft loans, grants and taxes
Heat recovery
Servo drives
Encourage stability in markets and encourage banks to lend Banks (loans) Carbon Trust
Provide finance at reasonable rates
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Additional operational cost
All
Lack of management support - energy a low priority
All
Metalformers
make energy consumption part of the monthly balance sheet review for site managers
Government Carbon Trust
Fund external support - hands-on advice and consultancy
CBM Lack of specialist technical knowledge / resource
All
Metalformers
Metalformers to dedicate greater resources to energy efficiency Employ specialist technical expertise in energy Buy in specialist external support
Government
Government funding for employee technical training (currently provided in Wales, but not England) Encourage development of technical skills in schools, colleges and universities
Carbon Trust
Fund external support - hands-on advice and consultancy
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Low confidence in savings and viability All
CBM
Employ specialist technical expertise in energy - available to sector members
Metalformers
Partnership working between metalformers to demonstrate technologies
Suppliers
More independent verification Suppliers to provide guarantees on performance and energy savings
Carbon Trust
Publish practical information for the industry Produce case studies showing performance, cost, savings and payback
CBM
Possible role for sector adviser in facilitating partnership working between metalformers Employ specialist technical expertise in energy - available to sector members
People with pace makers can’t go near induction heating systems
Induction heating
Suppliers
Suppliers must clearly communicate this risk
Metalforming Sector Overview
Companies may not have the available power capacity to run induction heating systems
Technical viability to retrofit
Short payback periods required for investment (1-2 years)
77
Induction heating
Servo drives
All
Metalformers
Ensure people with pacemakers don't go near induction heating systems.
Metalformers
Liaise with energy supplier and possibly increase power capacity
Metalformers
Plan production so that Induction heating is run at time when other large electrical equipment is off
Suppliers
Provide information on retrofitting
Carbon Trust
External advice, case studies
Metalformers
Review suitability of current investment criteria, taking account of predicted energy and carbon prices
Government
Soft loans, grants and taxes Encourage stability in markets and encourage banks to lend
New systems required for new kit (H&S, All IT etc.)
Banks (loans)
Provide finance at reasonable rates
Suppliers
Reduce costs
Suppliers
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Metalformers Low turnover of capital equipment
All
Metalformers Suppliers
Solutions need to be robust
Burner controls
Provide solutions that can be retrofitted to existing machines
Suppliers
Process control of furnaces Lifetime of electrical systems and Burner controls software is shorter than plant lifetime upgrades and new systems may not be compatible with old systems
Uncertainty over refractory material tolerances (when assembled)
Metalformers
Process control of furnaces
Suppliers
Process control of furnaces
Metalformers
Engage with suppliers to better futureproof electrics and software
Engage with suppliers to better understand tolerances of furnace materials
Suppliers
Shutdown requirement to implement improvements
All
Research institutions / Universities
Research into material furnace material tolerances
Metalformers
Build shutdown requirements into investment business cases
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The Carbon Trust receives funding from Government including the Department of Energy and Climate Change, the Department for Transport, the Scottish Government, the Welsh Assembly Government and Invest Northern Ireland. Whilst reasonable steps have been taken to ensure that the information contained within this publication is correct, the authors, the Carbon Trust, its agents, contractors and sub-contractors give no warranty and make no representation as to its accuracy and accept no liability for any errors or omissions. Any trademarks, service marks or logos used in this publication, and copyright in it, are the property of the Carbon Trust or its licensors. Nothing in this publication shall be construed as granting any licence or right to use or reproduce any of the trademarks, service marks, logos, copyright or any proprietary information in any way without the Carbon Trust’s prior written permission. The Carbon Trust enforces infringements of its intellectual property rights to the full extent permitted by law. The Carbon Trust is a company limited by guarantee and registered in England and Wales under Company number 4190230 with its Registered Office at: 6th Floor, 5 New Street Square, London EC4A 3BF. Published: August 2011
Š The Carbon Trust 2011. All rights reserved. CTG062