Engineers Without Borders UWE Bardsey Bird and Field Observatory Audit Report 2013/14 EWB // UWE Trip
Centre for Alternative Technology, Coed y Brening mountain biking centre & Dinorwig power station
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s a first year Architecture and Environmental Engineering student I have never had such eye opening and hands on experience with relation to sustainability, vegetarian food & hydroelectricity as was offered at the Centre for Alternative Technology (CAT). Nor had I seen such a vast and impressive engineering project such as Electric Mountain, Dinorwig. The EWB weekend trip was highly structured and showed careful planning; architecture, engineering and
sustainability were key themes which clearly ran through the weekend: from the restaurant on the first evening which had been carefully chosen for its interior architecture, the wisely thought out design to CAT’s community led eco structures and its new prestigious WISE building to finally the monstrous pumped storage facility at Dinorwig. CAT gave us three highly informative tours, workshops and talks on topics ranging from zero carbon economies to do it yourself renewable technologies.
The ‘Zero Carbon Britain’ talk gave an insight into CAT’s vision on dealing with the current environmental situation. The talk covered what systems and cultural shifts would be required to meet such a challenging goal and the associated positives and negatives of each were highlighted giving a balanced and informed argument. The theme of hydroelectricity ran throughout the trip: a hands-on workshop on the first day gave an opportunity to understand some simple concepts on hydroelectric power generation.
The hydro showstopper came on the second day with a trip to the ‘Electric Mountain’. The group were given a talk and a tour of the massive cavern that housed the pumped storage power station. Through all the team building tasks (willingly under taken by all), social activities and one epic game of sardines a real sense of EWB membership was formed. James.
Andy Elliot • Fred Hagley • Anna Sturtivant • Jack Gorman • Michaela Mallia • Will Webb • Adnani Fazal • Harley Felts • Kareem Cheng • Gwyn Stacey • John Holdich • Josh Frend • Keir Sweeney • Tom Gravell • Alec Litchfield • Nik Trowles • Cameron Halpin
The EWB UWE Team
Checking out Coed Y Brenin
How to wear a hair net with style
Hydro Workshop
1 Sustainable construction materials
Dinorwig pumped storage power station
1 • INTRODUCTION Foreword
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A wise man once told me, that the best of us are those who are lucky enough to not lose sight of the important things in life as all the apparently urgent stuff vies for our daily attention. Sporting deep personality traits, such as altruism and empathy, such people are those who find time amidst the frenetic demands of architecture and engineering degrees to work on voluntary projects that make significant differences in the real world. Taking time out of their summer and, at their own expense, traveling to a place most have never heard of, to see if their skills and knowledge could help to make it better. It is clear to me that the Bardsey Island group are just such people and they give the rest of us hope.
Having grown up in close proximity to the island communities of West Cork and still spend my summers exploring the wilds of Carbery’s Hundred Isles, I am well aware that the rugged wildness of such environments often mask their delicate nature and the people who oversee them often require significant resources. So studies such as this, which have the aim of helping the visitors and residents of Bardsey Island to use their resources more efficiently and lower their impact on the environment are both welcome and vital in developing much needed resilience.
An honourable undertaking, executed and resulting in a of positive outcomes, not which is one very proud
expertly plethora least of lecturer.
Well done to all involved, Patrick O’Flynn Senior Lecturer in Energy Management & Building Services Department of Architecture and the Built Environment, University of the West of England, Bristol.
1 • INTRODUCTION 1. Introduction Report Summary Acknowledgments Engineers Without Borders Report Aims
5. Energy 4 5 6 7
2. Bardsey Island Location Cristin
8 9
3. Cristin 3.1. Survey History Building Uses Cristin Plans Cristin Yard Plans Listed Buildings Environmental Strategy Structure Materials 3.2. Fabric Thermal Performance Air Tightness & Infiltration Recommendations
10 11 12-13 14-15 16 17 18 19 20 21 22-23
32 33 34 35 36 37 38 39 40-41 42 43 44-47 48 49 49
6. Waste Overview Recommendations
50 51
7. Conclusion
4. Water Storage Distribution Quality Demands Waste
The Wider Issue Cristin Energy 5.1. Space Heating & Hot Water Overview Distribution Performance & Efficiency Recommendations 5.2 Electricity Generation Demands Battery Systems Performance & Efficiency Recommendations Circuit Diagrams 5.3 Gas Overview Performance & Efficiency Recommendations
24-25 26-27 28-29 30 31
Summary Highlighted Recommendations
52 52-53
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1 • INTRODUCTION Introduction
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This report is the culmination of a visit to the Bardsey Bird and Field Observatory (BBFO) by a group of 16 students from the Engineers Without Borders society at the University of the West of England. From the outset the purpose of the project was twofold.
Firstly the project would help to develop and improve our skills as engineers; thinking critically to achieve sound recommendations that were both practically possible and appropriate in the small island context. Secondly we saw that BBFO and the wider Island community could benefit from our skills and knowledge to provide a platform for positive change towards more sustainable solutions.
The report will hopefully be used by both BBFO and EWB UWE. Hence, the report starts by setting out the unique island context - information that is very familiar to those that visit regularly. The report then moves on to analyse and discuss systems and provide recommendations - something that as engineers we do day to day. For any more information on the report and the project, please contact:gwyn.t.stacey@hotmail.co.uk
1 • INTRODUCTION There are a number of people we wish to thank for allowing this project to happen and providing their insight and knowledge.
Bardsey Bird and Field Observatory For allowing us to visit and running this project.
Bardsey Island Trust For showing us their solar systems and providing information on water quality.
The Staff and Residents of Bardsey For your input and advice on the nuances of island living.
UWE Staff For their support knowledge.
Trinity House For a guided tour and a trip up the lighthouse.
The ‘Bardsey Island’ Team For their countless hours of hard work getting all this together.
and
Acknowledgments
technical
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1 • INTRODUCTION Engineers Without Borders Summary
Introduction Engineers Without Borders UK is an organisation that works to create massive small change by empowering thousands of new engineers to remove barriers to human development. Approach Their approach is to put students and young professionals at the centre of operations and to provide them with resources and contact to enable them to become ‘development professionals’. EWB-UK works with an interdisciplinary approach to take into account local knowledge, the economy, cultures and the environment to solve problems and provide solutions. They want to adopt a sustainable use of natural resources and minimise any impact to local environments, biodiversity or the global climate. By working with modern engineering methods alongside existing low-risk technology engineers can provide appropriate technology to situations.
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EWB-UK Engineers Without Borders UK essentially works through various student branches, or networks, located in Universities across the UK on projects, competitions, outreach, training and placements. The student branches are provided with a huge extent of resources, information, contacts and support to enable them to go forward with their skills and knowledge to improve the lives of others through engineering.
EWB-UWE EWB–UWE is the student branch of Engineers Without Borders located at the University of the West of England. In collaboration with Bardsey Bird and Field Observatory (BBFO) a project was set up to conduct an energy audit. The purpose of this trip was to benefit the residents of the Observatory and the island with the findings from the audit as well as to improve skills and knowledge of the students who went.
1 • INTRODUCTION Overview The report follows an audit conducted by Engineers Without Borders UWE, in September 2013. The audit was carried out on Bardsey Island for the Bardsey Bird and Field Observatory. Format The audit and report are split into a number of sections, • Survey & Built Fabric • Energy, • Water • Waste. Each section outlines the current systems and services in place at the observatory.
Following this, within each section are a number of suggestions aimed at improving the outlined systems. The suggested improvements are both short and long term solutions. All short term suggestions are intended to be cheap and easy to initiate. Long term suggestions may well have a higher cost and level of difficulty associated with their implementation, however, they will give higher energy and financial savings over the current systems.
The recommendations outlined aim to provide a platform for BBFO to operate more efficiently and sustainably, reducing running costs and ensuring the work of the Observatory can continue into the future.
Report Aims
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2 • BARDSEY ISLAND Location Bardsey Island, or Ynys Enlli, is a 1.8 km2 isle located 2 miles west of the Llŷn Peninsula in Wales. The Island is accessible via a boat service which leaves from Porth Meudwy, about a mile or so from Aberdaron. Strong winds, rough seas and fierce currents often make the journey between the mainland and Bardsey too treacherous. The island’s location is significant, forming part of various birds’ migration routes. It is a notable summer nesting ground for numerous bird species, such as Choughs, Auks, Gulls, Shags and Manx Shearwaters; the latter are known for their incredible cacophony of calls. It is common to see gray seals and dolphins in the waters surrounding the island.
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Bardsey Island
2 • BARDSEY ISLAND Cristin Site Plan // 1:500 Key Water Tanks Generator Oil Tank Heligoland Trap Toilets Buildings
Established in 1953, the island’s Bird Observatory was set up in one of the islands listed buildings – Cristin. The island has a single track on its flat plain which leads from Cafn, on the southern part of the island, to the north side. The Observatory and the other buildings are dotted around this track. Cristin is set above and to the east of the track at the base of Mynydd Enlli, a steep 167m mountain that spans across the eastern part of the island. Cristin is made up of two buildings: the barn and accommodation. The barn to the south consists of the Observatory Warden’s residence, a gift shop and a number of workshops. The accommodation to the north includes an office, a library, sleeping quarters and a kitchen - all for use by observatory staff, volunteers and guests.’
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3 • CRISTIN Island History The island has a wealth of history with early signs of habitation from 20001000 B.C. The spiritual history, as well as the history of the farming and fishing community are a unique aspect of the island, the history of the island must be an important factor in looking forward to the future.
Crisitn History Built in 1874, Cristin comprises two houses, originally Cristin Uchaf and Cristin Isaf (upper and lower Cristin). The two houses had a shared farmyard. The house originally belonged to Kings William Jones I and II. In 1953 the Bardsey Bird and Field Observatory was formed and took permanent tenancy of Cristin.
Historical island photographs - www.bardsey.org
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3 • CRISTIN Building Uses The houses of Cristin are used as accommodation for paying guests to the observatory in a hostel style arrangement. All sleeping accommodation is situated upstairs with shared facilitates downstairs such as kitchen, dining room and washroom. In the old farm buildings surrounding the yard are a mixture of spaces used for both public and private Observatory work. In the south east corner of the yard is the accommodation for the Observatory Warden and family. Cristin - Accommodation Courtyard Buildings - Mixed Use
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3 • CRISTIN 3.1 • Survey
Cristin Ground Floor Plan
Living Service Study 12
3 • CRISTIN 3.1 • survey
Cristin First Floor Plan
Bedroom
13
3 • CRISTIN 3.1 • Survey Cristin Barns Ground Floor Plan
Public Facilities Storage & Workshop Living Bedroom 14
3 • CRISTIN 3.1 • survey Cristin Barns First Floor Plan
Storage & Workshop Bedroom 15
3 • CRISTIN 3.1 • Survey Listed Buildings Listed buildings are buildings which are deemed to be of high architectural or historic value. CADW is the Welsh agency that monitors and records listed buildings. Buildings are listed under three bands; I, II* and II, with Grade I listed buildings being exceptionally important and grade II being of special interest. Each grade of listing will impose a level of protection on the building or structure, which limits future changes.
Cristin Cristin is a Grade II listed building due to its “distinctive double farmyard, which is a good example of later C19 model farm housing” (CADW. 1974)
What this means Cristin, including its walls and yard, is a Grade II listed building. When works are planned to alter the interior or exterior, the character of the building will also be changed; this means that an application would have to be made in order to attain listed building consent. What is deemed as altering the character is sometimes unclear and as such professional consultation should be sought.
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Cristin - House and Yard buildings
3 • CRISTIN 3.1 • survey
Environmental Section Diagram Environmental Strategy Ventilation
The buildings are ventilated passively allowing fresh air in and out through window openings and chimneys. In the winter, warm air can escape through unsealed gaps in the structure and around doors and windows as well as through the chimneys creating undesired losses.
Solar Consideration Slightly recessed windows provide a minimal amount of solar shading. Most shading is done through internal blinds and curtains, however, due to the building’s function, overheating and glare are rarely an issue.
Surface run-off Rainwater is harvested from a proportion of the roofs at Cristin in tanks, where it is then used for washing.
Odours and Noise There are a small number of locations within the curtilage of Cristin where odours are noticeable; these are marked on the plan by brown circles. Noise pollution is noticeable from the generator in this otherwise peaceful location. No acoustic insulation is used within the buildings however their mass reduces noise significantly.
Environmental Plan 17
3 • CRISTIN 3.1 • Survey Structure Foundations are probably limited to stone and lime mortar laid into a shallow footing excavated to firm ground or bed rock.
Roof slates - mortar sealed in places Original cut timber roof structure
The masonry is of locally quarried stone laid with lime mortar finished externally with painted sand and cement render, and internally with traditional lime based plaster.
Glasswool insulation ≈ 100mm Black plastic guttering Local masonry walls
The joinery consists of painted single glazed timber sash windows and painted timber doors.
Timber floorboards Timber first floor structure
The roof is a traditionally cut timber structure with slates fixed onto timber battens. There is no roofing felt but lime mortar has been applied to slate joints internally to reduce draughts and driving rain.
Slate lintels Single glazed timber sash windows Painted internal render External render/ Exposed masonry Quarry tile/Exposed timber floor Leveling sand & hard-core rubble Earth Constructional Diagram **not to scale**
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3 • CRISTIN 3.1 • survey Key Materials A range of materials are used in the construction of the observatory, these include:
2
6 9
1 Brickwork chimney 2 Slate tiles 3 Slate lintels and sills 4 Painted sand & cement render 5 Locally quarried stone 6 Timber joists 7 Slate floor slabs 8 Wood framed windows 9 Single glazing 10 Plastic guttering 11 Wooden stairs
5 8
3
1
10
6
5
4
7
11
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3 • CRISTIN 3.2 • Fabric Thermal Performance & U-values When heating or cooling any building its thermal performance is key to ensuring it runs efficiently without any unnecessary loss of energy. The greater a building’s thermal performance, the more effective the systems will be. With improved effectiveness of systems comes a reduction in fuel use. There are a number of simple measures that could be undertaken to improve thermal performance of the buildings at Cristin. Improved occupant behaviour with these simple measures will increase effectiveness further.
Measuring Thermal Performance A U-value is a method of calculating the amount of heat transferred through the materials used to construct a building’s external elements; walls, roofs, floors and windows. U-values describe the overall heat loss rate through a building’s envelope and therefore signifies how well the building retains heat. A higher U-value represents a higher amount of heat loss. Therefore, a lower U-value tends to indicate higher levels of insulation within the construction. The importance of establishing U-values lies in the emphasis that is placed on the energy efficiency of buildings in the construction industry. In practice, every external building element of a new build must comply with the thermal standards set out in the building regulations. Every pre existing building that is restored or converted should meet the targets set out in Building Regulations document L2A, as can be shown below. Limiting Fabric Parameters Roof
0.25 W/m2K
Floor
0.25 W/m2K
Wall
Windows, roof windows Rooflights
Roof ventilators
Air permeability
Cristin’s Thermal Performance Cristin’s calculated U-values are as follows: Area
U Value (W/m2K)
Cristin Walls
1.53
Single-Glazing Windows
5.80
Cristin Roof
2.64
Barn Walls
1.60
Listing Although Cristin is a listed building there are a number of measures that could still be employed to improve thermal performance. These measures will be limited to internal alterations only and would be the responsibility of BBFO not the Bardsey Island Trust (BITL).
Glazing Windows are particularly conductive. Building Regulations part L1A state that windows must have a U-value equal to or smaller than 1.8. The very best triple glazed windows might achieve a U-value as low as 1 and double glazing may range between 1.2 and 2.2. Comparing these to Cristin’s single glazing with a U-value of 5.8, it is easy to appreciate the difference installing thermally efficient glazing systems would make.
0.35 W/m2K 2.20 W/m2K 2.20 W/m2K 3.50 W/m2K 10m3/hm2
20 Windows are a particularly conductive part of an envelope. Building Regulations Part L1A state that
3 • CRISTIN 3.2 • Fabric Infiltration at Cristin Walls Cristin’s stone walls likely have a number of cracks in the mortar, providing passages for air to flow, however this is likely to be the most minor source of infiltration. Openings As is often the case with solid wall buildings, the doors and window frames in the observatory may not fit perfectly into the wall openings. As a result of this, infiltration will occur around windows and door frames. Services Drilled routes for pipes and cabling into the walls also introduce passages for air flow causing infiltration. Chimneys Unsealed or loosely sealed chimney stacks create further avenues for air movement through the building envelope. However, completely sealed chimneys with no air flow causes condensation to occur internally. This in turn causes damp and degrades the buildings structure.
Seasonal Impact - Summertime During the summertime infiltration is rarely an issue. On hot dry days, windows and doors are left open and air is allowed to flow freely around the building. On cold damp days doors and windows are closed and this adequately reduces most draughts. However this reduction in airflow with a large number of often damp occupants, and the use of gas ovens causes a large amount of water vapour which condensates on cold surfaces such as walls and windows, degrading them over time. Seasonal Impact - Wintertime During the wintertime the cooler external air is more evident in drafts around doors and windows, causing discomfort. Heated air from the central heating system can also escape, reducing the effectiveness of the system and wasting money spent on fuel. In the kitchen and dining room the air will remain damp due to closed doors and windows.
Improving Air Tightness Infiltration is usually combated by draught proofing doors and windows in buildings and blocking up service penetrations and unused chimney stacks.
Air flow around a window frame
Infiltration - Overview Infiltration is the unintentional introduction of outside air through the cracks and joints in the buildings walls, floors and roofs. This is caused by a difference in pressure from the inside of the building to the outside environment. Generally infiltration is unwanted as it reduces thermal comfort of occupants. This can be caused by cold air entering a building or heated air escaping, causing heat losses. To combat this, building regulations stipulate certain requirements to be met during construction of building envelopes. When considering improving air tightness of a building, it’s important to consider airflow through the walls, doors, windows and services penetrations including chimneys and flues.
Air flow through a chimney
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3 • CRISTIN 3.2 • Fabric Thermal Performance Improvements
Roof & Floor insulation
If spaces are heated they should, as a minimum, aim to retain that heat to the maximum possible level in the given circumstance.
Roof Cristin has approximately 100mm of insulation at ceiling joist level. This can easily be increased with an additional layer of insulation. In the yard buildings (wardens, assistant warden and volunteer accommodation) insulation should be installed at joist level where possible and rafter level where this is not possible. Care should be taken to ensure no insulation is in contact with roof slates as this can cause condensation to occur degrading the insulation and roof structure. Floor Where there are exposed floors, such as the warden’s bedroom, insulation should be installed between the joists and sealed in place with sheeting. This area is often used for nesting Swallows and as such a proportion of the floor can be left to allow Swallows to build their nests. Insulation Choices Rigidboard insulation should be chosen to insulate in between rafters and joists when being supported from below. Ceiling voids can be insulated by soft insulation. It is our recommendation that low embodied energy insulations are chosen for their environmental credentials.
The buildings at Cristin should not be seen as an exception to this, hence measures should be considered to reduce losses. There are a number of benefits to doing this: • Reduced energy/fuel use • Reduced costs • Improved comfort for occupants • Improved profiling of temperatures • Reduced damp and condensation • Greater lifespan of building structure • Less maintenance costs
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Internal Wall Insulation. Internal wall insulation would require the most work and be the most costly. However the introduction of 100mm of rigid insulation could reduce the U-value of Cristin’s walls from 1.5 to 0.2. Internal wall insulation is installed by first placing a frame of timber battens on the wall. The rigid board insulation is then attached to the battens with a vapour barrier. This is then plastered and painted to tie into the existing style. Internal wall insulation is only advised following the implementation of roof and floor insulation as well as secondary glazing. The insulation will reduce internal floor area by approximately 150mm around the perimeter. Detailing around windows and doors can also be complex; however its implementation will bring the thermal performance of the building almost in line with current standards.
Secondary Glazing By installing secondary glazing the U-value of glazing can be reduced from 5.8 to 1.7; almost as efficient as modern double glazing. Secondary glazing is a highly effective method of reducing heat loss at only a minor cost. Secondary glazing is an acceptable option for a listed building as it still retains the character of the original window. Where windows are open-able, secondary glazing can be situated as a temporary measure to be removed in the summer. Permanent secondary glazing can be placed on windows which do not open.
Secondary Glazing
Rigidboard Rafter Insulation
3 • CRISTIN 3.2 • Fabric Secondary Glazing As well as the improvement in thermal performance, secondary glazing can improve the infiltration through windows, especially sash windows. Where temporary secondary glazing is installed around open-able windows, the infiltration reduction is only achieved when it is closed, which should be during the winter. This will mean that the infiltration may increase during the summer, however the warmer outside air makes this less of an issue. Secondary glazing can have timber, UPVC or aluminium frames and at a higher cost can also be openable. It is recommended BBFO draws upon its volunteer base to construct the windows to reduce cost. As a benchmark commercial rates for openable UPVC secondary glazing ranges from £40-80 per window.
Sealing Services Joints Where there are penetrations through walls or windows by cabling or pipes, these should be sealed. There are a number of ways this can be done, however, the cheapest and simplest method is to use expanding foam. A liquid is injected into the hole which then expands around the pipe or duct to seal it. Expanding foam or mortar can be used to seal window and door frames.
Door & Window Strips Infiltration can occur where doors or open-able windows meet their frames or where sash windows slide. To reduce this, rubber or brushed draught strips can be installed. These improve the seal of the open-able window to its frame. Bad example The door into the ringing hut. Good example The door into the Warden’s barn.
Reducing Infiltration As well as implementing measures to improve the thermal performance of building elements, measures should be adopted that will reduce the loss of air through infiltration. Some of these measures are quick and easy to implement and will each contribute to the benefits listed on page 23.
A pack of 5, 1 meter draught strips can be purchased for £8.05 from Screwfix. It is recommended that draught strips are installed on all external doors and windows.
Expanding foam injection
Washroom unsealed penetration
A range of draught strips 23
4 • WATER Water Storage Overview The water storage at Cristin is split into two separate systems deriving from two separate sources. Rainwater is harvested from roofs and stored in a range of tanks. This water is used for outdoor and washing purposes. Groundwater is collected from a nearby well and stored in a series of tanks until it is supplied to a range of taps; these supply drinking water to staff and guests at the Observatory.
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Cristin Rainwater Storage Four rainwater tanks are situated at the rear of Cristin. They are able to collect approximately 5140 litres of water. Water is supplied to the far right and left tank. The tanks are connected at the top so that when the outer tanks are filled they overflow into the inner tanks. Overflow from the tanks is away from the building and into a soakaway drain. Connections at the top of the tanks reduces the risk of leakage but reduce flexibility of use. The primary use of the collected rainwater is to clean out the outdoor toilet buckets. The tanks also supply the washroom hot water supply by means of a pumped storage system. The tanks are not entirely covered and are prone to collecting unwanted organic matter which can taint the supply. The two corrugated steel tanks are rusting and often leak, reducing the storage capacity.
Cristin Barns Rainwater Storage A single 1000L tank collects rainwater from the roof of the barns. This rainwater is used by Observatory staff for a range of outdoor uses. A secondary 5000L capacity tank situated in the yard is filled with rainwater but is not used. In a dry period, or when more rainwater is required, this water could be used and ‘plumbed in’ to increase the capacity of the rainwater system and better utilise the runoff from the roof of the barns.
Cristin Pumped Storage A 1000L capacity tank is reserved entirely for pumped rainwater storage. Water is pumped up 6m from the Cristin rainwater tanks to fill this tank when the well is running low. A 12v battery powers the pump. The water quality coming out of the shower and washroom taps is reduced when this system is implemented and guests should be notified. Weathering has seen the black coating of paint on the tank peel away allowing light to penetrate. This will allow algae growth and stagnation in the stored water.
4 • WATER The Well BBFOs water is provided by the well, situated to the south east of the Observatory. The well also supplies Ty Pellaf and Rhydynogoch by an overflow pipe situated higher up the well. The well is thought to be supplied by rainfall on the mountain. The supply has only been known to dry up twice in the period from 2005 - 2013. A rudimentary dipstick is used to measure the depth of the well.
Primary Black Tanks These primary tanks, supplied directly from the well and controlled by a ballcock valve, can hold approximately 2375L acting as a single tank. Water from these tanks supply both the north & south tanks. The tanks are made of fibreglass and painted black; sunlight can penetrate the shells where the paint has peeled away. Airlocks caused by the fluctuating level of the well are cleared at this point when a drop in the water level is identified.
North Side IBC Tanks These 4 tanks work as one with a capacity of 4000L. These tanks are filled from the primary black tanks above. These tanks supply the washroom in the north side of Cristin, however, they can also be transferred to supply the south side of Cristin and the Cristin Lloft. All four tanks appeared to contain organic growths due to sunlight penetrating the shells where the paint has peeled away.
The Green Tank - South Side Supply The 8000L green storage tank supplies the observatory directly with drinking water which is subsequently passed through a UV filter. The water level is regulated by a ballcock valve. Upon inspection the inside of the tank appeared relatively clean due to its covering, however some sediment was present at the bottom of the tank.
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4 • WATER Water Distribution Plan The plan highlights the flow of water from source to use. Water initially flowing into the two primary black tanks then flows north where it splits to feed the 4 IBC tanks supplying the north side and the large green tank supplying the south side. Rainwater is collected and is used at the collection point or is pumped up to feed the hot water system when needed. A 5000L water tank and one IBC 1000L storage tank sit within the yard, only the smaller tank is used regularly.
Rainwater Drinking water
Cristin Water Distribution Plan 26
4 • WATER Water Distribution Schematic The schematic shows the fall from the well to each tank and the eventual point of use. The schematic highlights how the hot water tank can be filled from both well water and rainwater. Hot water is no longer supplied to the kitchen due to the time taken for hot water to reach the tap. When the hot water system is running on rainwater, it feeds both the hot and cold water in the washroom. This makes the rainwater in the washroom unpotable.
Rainwater Drinking water Hot Water Cristin Water Distribution Schematic
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4 • WATER Water Quality The storage system at Cristin is in a poor condition and is not maintained regularly enough, hence the quality of the water is often not fit for consumption. This is remedied by the use of a UV filter. This is not a foolproof system and ensuring water quality should not be left to the final hurdle. Instead, the quality of the water should be as high as possible straight after collection so it is stored with minimal chance of bacterial growth. Water quality is discussed in further detail as well as providing a graphical representation of quality.
Pass • Fit for Human Consumption
Fail • Marginal Fail • Improvements required
Drastic Failure/No Data • Unsafe for human consumption • Improvements required
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The Well There are several points across the water system that require extra attention in maintenance. The well, which provides water for Crisitin, Ty Pellaf and Rhydynogoch is currently covered by a loose fitting lid to reduce contamination of the supply. This does not completely seal the well, there are often roots and insects within the well. North side supply The north side supply tanks feeding the washroom have been subjected to considerable weathering, leaving the tanks semi-transparent. The penetration of light due to peeling paint has caused a build up of organic matter within each tank.
South Side supply The green tank was opened during the visit and appeared to be relatively clean. However, a small amount of silt from organic matter was present that had built up over time.
Tap water outlet The UV and sediment filter are currently the only water purification devices employed by the system. The drinking water taste can also be a factor to consider; currently the taste is described to have an unpleasant earthy taste. This taste comes from the stagnation of the water and the organic matter within the tanks.
2014
2013
2011
16
0
0
No Data
No Data
No Data
0
18
2
0
2
0
Coliforms No’s/100ml
Coliforms No’s/100ml
Enterococci No’s/100ml
4 • WATER Surface Algea Growth
Water tank Light penetration
Water Survey Gwynedd County Council conducts an annual study into the water quality of the island’s springs and wells. The study has outlined several areas of the water storage system which pose health risks across the island and at Cristin. Coliforms are regularly recorded within the water system. Coliforms are usually found within animal digestive systems and can be found in plant and soil material. The risk of contracting a water borne illness is higher if Coliforms are present in supply. In 2013 the supply to the Lloft Cristin was recorded to have 18 Coliforms.Cristin recorded only 2 Coliforms within water from the kitchen tap. As both taps tested are fed from the large green tank, the benefit of the UV-filter is evident however not foolproof as unfiltered and filtered water passes through the same tap. Both sources were stated to have failed in 2013. In 2014 the outlook was better with no Coliforms detected at the taps in Cristin and Lloft Cristin. However, water tested in Ty Pellaf contained 16 coliforms, which may indicate that contamination occurs in the well.
Quality Conclusions Although the conclusions of the report undertaken by Gwynedd Council for 2014 and 2011 was a pass, we are concerned about the quality of water present within the storage system. The report undertaken by Gwynedd Council does not test the washroom; the water used here is of serious concern as it is allowed to stagnate and warm in the 4 IBC tanks. When rainwater is used for this tap, the quality may be further reduced; although not directly consumed, guests will brush their teeth with this water twice a day The reports by Gwynedd Council highlight that any place where water could be ingested, whether directly or indirectly (for example washing food or cleaning teeth), then the quality should be to the same level as that for drinking water.
Quality Summary • System in poor condition • Quality of water is concerning • Washroom water unsuitable for cleaning teeth
Recommendations • As a short term solution, the IBC tanks should be emptied, cleaned, painted black and then painted white. • A new system should be considered, including; 1. A new lid for the well to reduce containments 2. New tanks with a greater capacity 3. Reuse of pipe work may be acceptable but only after treatment 4. A range of sediment filters and continuously on UV filters • Active quality assurance measures should be considered such as chlorination • Separate taps for potable and nonpotable water • Cross contamination of water should be avoided • A request should be made to test the washroom water as well as the kitchen and Lloft Cristin
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4 • WATER Water Demands With a source of water that is susceptible to running low, or even drying up during exceptionally dry weather, ensuring security of supply is paramount. Having an understanding of the demand of water can provide a base for procedures to minimise waste during dry spells. When visiting the observatory, careful use of water is regularly stressed to guests; therefore, demands are likely to be reduced due to an increase in awareness of mains water demand. By measuring waste water an estimation on water demand can be gained.
Washroom - Sink & Shower The washroom in Cristin has two water demands; the sink and shower. To manage demand the shower is reserved for staff only, except for when there is an abundance of water at which point guests can pay ÂŁ3 per shower. When measured, the shower used 8 litres per minute assuming a 10 minute shower and an average of 5 showers per week. The total amount of water used by the shower over a week would be 400 litres. The waste water from the wash room sink was not recorded due to impracticalities, hence a benchmark is applied to determine the water demand. A benchmark of 5l/person/day can be assumed for washing and brushing teeth.
Washing Machine An assessment was done into the water demand of the current washing machine at Cristin. It was calculated that on average 24 litres of water was used per cycle. If ten cycles are done a week the demand is 240 litres, making up a considerable contribution of the weekly demand.
Kitchen The water demand of the kitchen can be estimated from a combination of measuring waste water and the estimation of water consumed and used for cooking. An average of 5l/person/day can be assumed, calculated from measuring waste and predicting use.
Having a full load each time will ensure water is used efficiently. When considering a replacement washing machine, low water consumption should be a key factor in deciding upon a machine.
Demand from the Cristin Lloft was not included in the calculations, however, demand is always considered when supply is low.
Washing machine water usage 30
Cristin washing machine
4 • WATER Wastewater The greywater plan identifies where rainwater is harvested and stored and where waste water is discharged by soak away drains. A series of soak away drains discharge uncollected rainwater and waste water from the sinks and showers at Cristin into the ground. Four soak aways are dedicated to rainwater whilst the other are combined rainwater and waste water. Two of the soak aways are currently discharging at ground level which is undesired. The use of harmful chemicals should be avoided as there is no treatment of waste water.
Greywater Distribution Plan 31
5 • ENERGY Energy - The Wider issue
60 50 40
Burning Oil Gas Oil (Diesel)
30 20 10 0 2014
2012
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30 Year Fuel Costs - Department of Energy and Climate Change (DECC)
2030 fuel price projections - DECC 32
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Fossil Fuels The burning of fossil fuels releases greenhouse gases. Greenhouse gasses are a leading cause of global warming. The UK government has a legally binding target to reduce emissions by 80% by the year 2050. There are also European and global targets to reduce the global impact. As well as the negative environmental impacts, the cost of fossil fuels has been rising for the last 30 years. This trend may be set to continue, with even optimistic projections - assuming a large reduction in demand - predicting a fall of only 30% by 2030. Reducing demand on fossil fuels should not only be seen as a solution to reducing pollution, but also to providing energy security into the future.
70
pence/litre
The negative impact humanity has upon the world is undeniable. From the vast quantities of oil based plastic waste in our oceans, to the over reliance on fossil fuels driving climate change. It is imperative that every person, organisation and government does what they can to reduce the impact we have on our planet.
Cristin Energy - Overview Currently all energy used within the BBFO buildings is generated through the combustion of fossil fuels. The fuel is shipped to the island; stored; and used for generating electricity, space and water heating and cooking. Four fuels are used to provide this energy: • Propane • Butane • Gas Oil (Diesel) • Burning Oil As the cost of fuel rises so does transport. This is especially pertinent given the location of Bardsey and the added transportation cost. This chapter will focus on each of the systems at the observatory and provide some broad options for improvement/ replacement. We recommend that BBFO should try to reduce its fossil fuel consumption with an ultimate aim of eradicating its necessity altogether. This will both ensure future resilience of the observatory and help mitigate the effects of climate change.
Fuels and demands at Cristin
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5 • ENERGY 5.1 • Space Heating & Hot Water Systems Overview Space heating and hot water is split into two separate oil fired system. One system supplies Cristin and the other Lloft Cristin. Oil is shipped over approximately 3 times a year. It is transported to the island in 25 litre drums and then pumped into the two oil storage tanks.
Cristin oil fired boiler Cristin has an oil fired central heating system common in dwellings where mains gas is not available. An oil tank situated on the north side of Cristin feeds the boiler (approx 25kW) in the washroom. The oil is burnt to heat water. This water is then passed around the central heating system feeding the radiators and a pre insulated hot water cylinder. The exhaust fumes from the boiler pass through a flue into the back passage at Cristin. Electricity is required from the generator to power the boiler and the heating pumps. Efficiency It was noted during the visit that the exhaust fumes from the boiler were unpleasant. The reason for this is the boiler is failing to combust all of the oil and is hence creating toxic fumes. The boiler at Cristin is approximately 7075% efficient. Modern gas condensing boilers are 90-92% efficient
Cristin oil storage tank 34
Control and Usage The central heating system is controlled via a thermostat in the boot room. The system is set to only be turned on when required. The usage pattern and control of the system is very different to a standard mainland system. During the summer the heating is rarely turned on, only being used during exceptionally wet periods to allow guests and staff a chance to dry clothing. During the spring and autumn the heating is turned on for thermal comfort. This is either done when guests request the heating, or when one of the staff members feels it has either been particularly cold or wet. Normally a heating system is programmed in accordance to occupancy pattern.
Central heating system schematic
Lloft Cristin AGA Lloft Cristin has an oil fired AGA which provides hot water, background heat and hot plates for cooking. The AGA is fed from a oil tank within the garden at Cristin. Approximately 2/3 of the burning oil used at Cristin is used to fuel the AGA. Efficiency AGAs have an approximate maximum efficiency of 70%. Their relatively poor efficiency, minimal output control and often continuous use makes them undesirable when considering energy improvements. However, AGAs often hold a strong symbolic sense of comfort and warmth.
Lloft Cristin oil storage tank
5 • ENERGY 5.1 • Space Heating & Hot Water Cristin radiator distribution schematic
First Floor
Cristin - Heating Distribution Heating is distributed around Cristin via radiators. Radiators heat the air which then circulates around the room by convection. The supply temperature for the radiators at Cristin is approximately 70 0C. Hot water is heated within a pre-insulated copper cylinder. A coil of hot water, fed by the boiler, transfers its heat to the stored water in the cylinder. The cylinder at Cristin also has a 3kW immersion heater which is not currently used. A schedule of the radiators is shown below with a calculated total heat output of 25kW.
Ground Floor
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5 • ENERGY 5.1 • Space Heating & Hot Water Cost Performance & Efficiency Fuel: Burning oil Consumption: 3000 litres/year 8.2 litres/day Av Cost 2013: £2250/year £6.16/day Cost inflation: 10.8% (2010-2013) Av energy use: 90 kWh/day ‘Base’ energy use: 70 kWh/day ‘Peak’ energy use: 150 kWh/day
Chart Overview The chart below plots the consumption of burning oil at Cristin against temperature, visible sun and rainfall. Although some correlation was found, it was difficult to analyse the consumption in depth due to the uncertainty of consumption time. The consumption from November 2010 to April 2014 was assessed by measuring the quantity and time of burning oil delivery.
Temperature, Sun & Rainfall The temperature plotted identifies the annual fluctuations, with the peak of Summer 2011 and 2012 clearly identified. The sun days shows a cycle of peak sun days during spring and minimum sun days between November and January. The key rainfall event during the analysed period was during the autumn of 2012, where there was a marked increase in rainfall from the previous two years.
Consumption Analysis Overlaying consumption over these metrics identifies some correlation; during periods of sustained low temperatures and/or high rainfall there is increased consumption. High usage is evident during the particularly cold winter/spring of 2011 and the particularly wet period in late autumn 2012. The baseline consumption across the peak visitor season can be identified as the hot water demand.
Cristin:Lloft Split 1:2
Burning oil consumption against weather data
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Key
5 • ENERGY 5.1 • Space Heating & Hot Water Gas Condensing Boiler As an interim measure for improving cost efficiency, the replacement of the boiler should be prioritised. Replacement will reduce fuel consumption, emissions and cost. Replacing the current boiler with a condensing boiler will improve its efficiency from approximately 70% to 90%. As the AGA cannot be replaced with a more efficient system, the majority of burning oil demand will not be reduced. BBFO should set targets for the reduction of all fossil fuels. A manageable target for the complete removal of burning oil from cristin should be 2025.
Evacuated tube solar collector
Solar Technology A longer term solution for the production of hot water is the use of solar technologies. Conveniently, the occupancy of Cristin is greater when sun hours are greater increasing the effectiveness of solar technology. Solar technology is split into two forms of harnessing the power of the sun. Solar thermal converts solar energy directly into hot water. Solar photovoltaic (PV) converts solar energy into electricity. Solar thermal would require panels located on roofs in close proximity to hot water cylinders. A system could produce enough hot water to meet demand; any excess energy could be fed into the current heating system. The Renewable Heat Incentive (RHI) is a UK government initiative that will pay for each kW of renewable heat generated. A combination of solar thermal and solar PV could eliminate the need for burning oil to produce hot water.
Air Source Heat Pump
Recommendations
To provide an alternative to burning oil for heating, an air source heat pump (ASHP) could be implemented. This technology is similar to a fridge working in reverse.
There are a number of modifications to the existing system that will improve it’s efficiency. These modifications are also linked to improving thermal performance and air tightness. For the greatest reduction in fossil fuels, renewable technology should be implemented. This will not be without a cost, however, systems are highly likely to have a good payback time in conjunction with the RHI.
Flat panel solar collector
Air source heat pump
The energy within outside air is converted using electricity into hot water/air; this can then be used to heat a building. The system works most efficiently (demands less electricity for amount of heating produced) when the outside air temperature is high and the supply air/ water temperature is low. ASHPs are most efficient when used in conjunction with under-floor heating or low temperature radiators. For Lloft Cristin a hot air supply may be most efficient from an ASHP. For Cristin a wet supply may be most efficient with radiators converted to high efficiency low temperature radiators. ASHPs are currently eligible for the RHI.
Solar thermal system diagram 37
5 • ENERGY 5.2 • Electricity Generation Overview There are three electrical generators used by BBFO. One permanent generator powers Cristin on a daily basis, another generator is permanently situated at the LSA hut and the final generator is used for mobile demands or when specifically required. The primary generator at Cristin is only used for a small number of hours each day, hence demand is restricted to evening times only.
Diesel Generator Cristin is powered by a Lister 9kVA 3 phase diesel generator. The generator provides 220 - 240v alternating current (AC) electricity to Cristin. The generator is run on red diesel/gas oil. As the generator was designed for 3 phase generation, but now only produces a single phase of electricity, the system is oversized. The generator has benefited from regular maintenance with services conducted annually. The generator is located in the north east corner of Cristin’s curtilage within a small stone shed. There is no sound insulation within the shed which would otherwise reduce the noise pollution of the system.
Diesel Generator 38
Usage Electricity is generally provided between 7 and 10pm during the peak summertime months. This is for the use of guests and staff. Usage times increase in the spring and autumn when there are less daylight hours. The generator is also used on changeover days for cleaning purposes. Control The generator has no remote control systems; it is switched on and off at source with an electronic ignition. The generator has a separate 33 litre storage tank for the gas oil. This then supplies the generator by gravity. The fuel tank is refuelled manually from Jerry cans which are manually carried to the generator shed.
Small Generators There are two small generators which are also used by BBFO. These provide power for mobile demands when they are required. One generator is situated at the LSA hut for staff use and for illuminating the ground during lighthouse attractions. The lighthouse has now changed to a red flashing light so the demand on this generator is likely to be reduced. The second generator is used at the observatory or where power is needed elsewhere on the island, for instance for power tools. The demands on these generators are difficult to predict and assess, hence were not included into the scope of this report.
Small mobile generatior
5 • ENERGY 5.2 • Electricity Monitoring Currently there is no system in place for monitoring the electricity used by the observatory. During our visit an energy meter was used to gather data for the demands on the generator. Combining this with a measure of generator fuel consumption provided valuable data on system performance. On leaving the island, an ‘OWL Intuitionpv’ energy meter was donated to the observatory to allow continued monitoring. Although this was initially installed it no longer records data. We advise the monitor is re-installed and fuel consumption is measured to provide real time data on system efficiency.
Key Demands & Base Load There are a number of key demands of the electrical system at Cristin. These demands create the base load as well as the peaks in demand. The base load as shown on the chart below is the lighting system. During the time of analysis a range of incandescent, compact fluorescent (CFL) and LED lighting fixtures made up this base load. These have now all been changed to CFL and LED, thus reducing the base load. The key peak demands that draw significantly on the system are as follows; • Kettle • Vacuum Cleaner • Washing Machine
4000
Analysis The energy meter used provided demand data for the generator identifying the base and peak loads. The graph below shows energy usage for two hours during ‘standard’ evening use. A base load of around 1200W is identified from lighting. The lighting has been historically left on at all times when the generator is used to give it a base load. The 5 minute peak at 20:35 was due to the kettle; the kettle demanded approximately 2kW extra on top of the generator. The elevated section on the right of the graph shows the load increase as the chargers are switched on, giving an increase of approximately 2000W. Their fluctuating demand is discussed in detail overleaf.
Demands Overview A range of demands are placed upon the generator. There is a base load from the lighting, with battery chargers being a considerable additional ‘continuous’ demand. Items such as the kettle, washing machine, and vacuum cleaner make up peak demands. If the demand on the generator exceeds 4kW it struggles to produce enough power. Energy demands by visitors are negligible.
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5 • ENERGY 5.2 • Electricity Batteries Overview Battery systems have been integrated into the electrical systems at Cristin to provide continuous electrical supply to a limited number of demands. By using battery systems, the need for the generator during the daytime has been almost eliminated. Although the battery systems have been successful to date, their management is reducing their life span; to ensure these systems are cost effective their use must be carefully considered.
Battery Systems Five battery systems are used around Cristin. These power a range of appliances, from computing to moth traps. The battery systems range in size and capacity depending on demand and length of use. The systems are set to automatically charge when the generator is on converting 220-240V AC to 12V DC. Inverters are then used to convert the 12V DC back such that it can be used by mains appliances. Specific systems A plan of the battery system locations and their details is shown overleaf. These systems are as follows. 1. Ringing Hut - This system charges a battery for mobile scientific use, such as moth trapping or tape players. 2. Gift Shop - The system powers a TV that displays a slideshow to visitors. 3. Food Shop - Two batteries power a number of office appliances in Lloft Cristin and a 60W moth trap during the night. 4. Water Filter - An 8W UV filter is used when drinking water is required. 5. Office/Library - This system powers the internet and some office appliances in Cristin.
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Battery Health Batteries can be grouped as deep and shallow discharge. This refers to the amount a battery can be discharged (depth of discharge) whilst maximizing its lifetime. Shallow cycle batteries, which are commonly found in cars, will become damaged very easily if they are discharged heavily. Deep cycle batteries benefit from thicker lead plates, increasing the depth of discharge they can handle. All batteries will inevitably loose their capacity over time as they are repeatedly charged and discharged. The off grid community tends to go by a 10% rule, where batteries are not discharged beyond 10% of their stated voltage and are not charged and discharged above 10% of their stated current. This is a conservative estimate, as manufacturers generally state deep cycle batteries can safely be discharged to 50% of their charge without damage. Deteriorating battery health has been observed on the island, particularly with the relatively new battery for the moth trap. This is due to the repeated charge/ discharge cycle. To combat this in the future, it is important that batteries are sized correctly and are managed such that they are never allowed to be fully discharged.
Charger Analysis During the demand analysis undertaken, chargers were switched on part way though the analysis; the results of this can be seen on page 39. An increase of 2.5kW can be seen in the graph, when the three largest systems were turned on. The three largest systems which are detailed overleaf are as follows: 2 - Gift shop 3 - Food shop 5 - Office The graph also identifies that the demand by the chargers fluctuates considerably. This is due to the batteries being charged to full capacity and the chargers switching off. When the level of the battery then drops the charger restarts. This cycle of top up charging causes the high peaks and troughs in the graph.
Battery charging system
5 • ENERGY 5.2 • Electricity
Location Battery 1 Ringing Room 12V Leisure
Charger 12V, 15A,170W Output
Inverter 10.5-15V DC 120W Output
2 Gift Shop
12V, 30A, 240V Input; Numax 123000 12V, 30A, 240V Input; Numax
150W; 12V Input; 230V Output 1000W
3 Food Store
4 Water Filter 5 Office/Library
2 x 250 amp/hr C20 Elecsol EL250N 2 x 250 amp/hr C20 Elecsol EL250N 150W Elecsol
Numax
1 x 120W 1 x 600W
Powers Lighting; Charger; Torch; 10W Flourescent TV
5 4
Moth Trap; Barn Internet 8W UV Filter Internet; Laptops; Printers; AA Battery Chargers
2
1 3
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5 • ENERGY 5.2 • Electricity Cost Performance & Efficiency Fuel: Diesel/Gas Oil Av Consumption: 1800 litres/yr; 4.9 litres/day 1.1 litres/Hour 0.6 Litres/kWh Av Demand: 1.6 kW Cost: £1500/year £4/day Base load: 1.2kW Peak load: 5.5kW Efficiency Range: 8-37%
Fuel Costs Assuming the generator is used every day of the year, its daily fuel cost would be approximately £4.10. Assuming the generator burns 1.1 litres of diesel per hour the generator can be assumed to cost £1.05 per hour. This is not fully true as analysis has found that the longer the generator is run and the more load that is put on it, the less fuel the generator consumes per unit of energy produced.
Efficiency analysis By assessing fuel consumption against the energy generation, a broad efficiency range was calculated. The efficiency of the generator was found to increase with higher loads, which is typical of diesel generators. The maximum efficiency recorded was 37%. Counter-intuitively, demanding more from the generator will decrease fuel consumption per unit of energy produced.
Consumption Rate Analysis The second two graphs plot consumption against average power demand and operational time. A negative correlation was found in both of these suggesting that with increased demand and operational time, consumption per unit of energy produced is reduced. This suggests that to maximise efficiency of consumption, the generator should not be run for short periods of time and when it is run it should be run at a high average load (although not too high as to cause the generator to struggle). These calculations were, however, based only upon 5 days of generator use. For a more accurate analysis of consumption more data would be required.
Maintenance costs Maintenance costs were not fully investigated. However, when parts, lubricants and volunteer hours are accounted for the generator is likely to have high maintenance costs.
Generator performance graphs 1.4
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5 • ENERGY 5.2 • Electricity Solar PV panels As the current systems run by BBFO are all 240V AC, a 12/24V DC system for lighting and fridge freezers is dismissed. An array of PV panels is proposed to reduce the need for the generator. The array needed will be substantial in size to solely power the existing systems and the addition of new highly efficient fridge freezers. PV panels harness the most energy when facing South at a 30o angle. However , systems can be orientated due east or west. Regardless of system size, the current management structure cannot be continued and careful monitoring of generation and demand should be undertaken to ensure the system works effectively through periods of low sun.
PV panels
Wind Turbine Although PV panels are likely to provide enough electricity for the summer season, their generation potential will be greatly decreased during the winter and periods of prolonged overcast weather. Wind provides the most potential for energy generation, however, it is an active technology and comes with some drawbacks. The positives of wind are that it can produce electricity day and night and often when there is no sun there is plenty of wind. The increased generation of wind during the winter lends itself to the use of heat pumps for space heating. The negatives of wind are its potential to harm birds and produce noise. Some claim wind turbines are ugly, although this is subjective. Wind turbines also require more maintenance as they are mechanical. We recommend demountable wind turbines are used during the winter when impact on wildlife and visitors is reduced.
Storage & Backup To ensure electricity into windless nights, a certain amount of storage is required. Battery systems provide a method of ‘storing’ electricity for when it is required. The number of batteries and hence storage capacity depends upon the time the system is needed to cover without any generation. Battery systems are expensive and have a limited life span and this should be considered with regular payments into a replacement fund advised. In the short term the generator should be kept and connected to any future system to provide energy security if demand out stirps the stored capacity of the batteries. If renewables are employed and 24/7 electricity is available, care should be taken not to increase demand through unexpected electrical equipment and accidentally leaving equipment or lighting on when it is not needed. Automatic control systems should be utilised to avoid unnecessary demand.
3kW Kingspan Wind Turbine
Ex Lighthouse Batteries
Improvements It is clear that the reliance upon fossil fuels and an aging generator are unsustainable. To combat this a bivalent system of renewable technology should be employed to provide a secure source of electricity for BBFO. With continuous electricity available, systems such as the UV filter and fridge freezers can run continuously. However, this will inevitably increase demand from the current system. There are also opportunities for electric based heating, using immersion heaters for hot water and heat pumps for space heating. All of these technologies are eligible for the Feed-in-Tariff (FIT) if installed by a certified installer. In the meantime some easy wins are listed below for improving system efficiency:
Easy Wins • Currently space and water heating rely on the generator for electricity. Suggest switching boiler pump over to battery power. • Run generator only when needing high loads, eg. washing machine cycle. Increase the load by charging a larger number of batteries. • Where possible do all wash loads one after another rather than on different days.
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5 • ENERGY 5.2 • Electricity Circuit Diagrams Electrical distribution circuit diagrams for both sockets and lighting are displayed over the next four pages. These circuit diagrams can aid in the planning of any adaptations to the system.
Cristin sockets circuits
Ground Floor
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First Floor
5 • ENERGY 5.2 • Electricity Circuit Control
Cristin lighting circuits
Ground Floor
When a system of renewables and batteries are employed for powering Cristin, automatic control measures should be placed on specific circuits. Daylight sensing should be used for the lighting circuits with lighting only able to be used when external light levels fall below a threshold. This could then automatically switch off at a given time to ensure lights are not left on all night unnecessarily. Timer switches could be used for the lights above the stairs. This method of lighting control is difficult for the bedrooms as lighting is only currently provided through side lamps. Sockets for guests could be limited to specific times or when there is plenty of generation from renewables.
First Floor
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5 • ENERGY 5.2 • Electricity Cristin yard sockets circuits
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5 • ENERGY 5.2 • Electricity Cristin yard lighting circuits
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5 • ENERGY 5.3 • Gas System Overview Gas is used for a range of appliances at Cristin. Its primary uses are for the fridge freezers and cookers. It is also used for supplementary space heating. The main weakness of gas systems is the production of large quantities of water vapour which increases internal humidity levels. Gas systems are difficult to replace for cooking due to the high levels of heat needed.
Cristin Pantry Kitchen Office South Wall Cristin Yard Food Shop Barn Kitchen Barn Lounge East Wall South Wall North Wall
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Fridge Freezers Oven & Hob Space Heater Propane Cylinders
2 2 1 2
Chest Freezer Oven & Hob Space Heater Propane Cylinder Propane Cylinders Gas Storage Site
1 1 1 1 2
Ovens & Hobs Gas ovens and hobs are used in both Cristin and Lloft Cristin. They are used daily and are a vital part of the observatory. Two cookers are situated in Cristin for guest use, the other cooker is situated in Lloft cristin for the Warden. Gas cookers require regular testing to ensure they are safe to use and are not emitting any carbon monoxide from the incomplete combustion of gas. The cookers are fired by propane which is situated externally.
Fridges & Freezers There are three fridge freezer systems and one chest freezer.
Ovens & hobs
Gas fridge freezers
Two fridge freezers are situated in Cristin, one dedicated to staff use and the second to guests. The second fridge freezer is located in the Lloft Cristin for use by the Warden. The chest freezer is used for scientific purposes located within the food shop; this freezer is locked. Gas fridge freezers are very costly to replace when they reach the end of their life, hence a shift to highly efficient electric fridge freezers is recommended in conjunction with a renewable system.
Space Heating There are a number of gas heaters used in Cristin and Lloft Cristin to provide added space heating. Unlike the Propane cookers and fridge freezers, the heaters use the blue Butane bottles which can be used indoors. These space heaters are not fixed and can be placed where there is a need. There are three operational gas heaters which are commonly found in the barn, the gift shop and the office. This method of heating has its benefits over centralised systems, as it can be used in occupied rooms only as opposed to heating a whole building. However, the efficiency and cost of using the heaters is difficult to predict amongst other issues such as large quantities of water vapour produced.
Gas heater
5 • ENERGY 5.3 • Gas Storage Both Butane and Propane are delivered to the island and then stored in an enclosure at Cristin. Both full and empty gas cylinders are stored here when not in use. Smoking is prohibited in the vicinity of any gas cylinders around Cristin.
Strengths Providing enough heat for cooking is highly energy intensive; gas provides an ideal system for producing this heat. Producing heating for cooking from electricity will require highly efficient cookers and a large amount of generation. Other strengths of gas systems are the ease of transportation and storage. Weaknesses The key weakness of all gas systems is the quantity of water vapour emitted from its combustion. The quantity is considerable and causes an increase in humidity in the spaces where it is combusted; this has negative impacts on the built fabric of the buildings. The other weakness of gas systems is production of carbon monoxide. This only occurs when the gas is not burnt fully. All gas appliances should be regularly tested for carbon monoxide and sensors should be installed in all rooms where gas is used.
Storage enclosure
Alternatives There are a number of alternatives to the current systems. Fridge Freezers - A+++ Electric fridges and freezers used in conjunction with renewable and a battery system. Heaters - Electric Oil Radiators used in conjunction with renewables and a battery system. System capacity should be known before using oil radiators. - Centralised systems only.
Cost Performance & Efficiency Fuel: Butane Av Consumption: 9-10 cylinders/yr 2015 kWh/yr Cost: £270/year Fuel: Propane Av Consumption: 54 cylinders/yr 1 cylinder/week 14000 kWh/yr Cost: £1750/year £35/week
Cookers - Highly efficient electric ovens and hobs used in conjunction with renewable and a battery system. - Utilising anaerobic digestion of food and human waste to produce Methane on the island. An innovative system which would require a separate study to be conducted.
Cristin propane supply 49
6 • WASTE Overview Waste can be categorised into four types: • Rubbish and recycling - deriving from packaging, excess and off cuts. • Waste water - often referred to as greywater. Derived from washing, and surface run off. • Food waste • Human waste Waste is not considered in our daily lives on the mainland, however, in an offgrid community waste provides a real challenge to be dealt with effectively and efficiently.
Rubbish & Recyclables Under a policy introduced by the Bardsey Island Trust in 2013 all waste (apart from human and food waste) must now be removed from the island. Glass, plastic, tetrapaks and card are currently separated into three black bins which are then shipped off the island for processing and recycling on the mainland. Waste removal is the responsibility of visitors.
Although the majority of waste water at Cristin is drained into soak aways, there are a number of waste water drains which outflow directly onto the land. This is undesirable as this produces an odour and greater surface runoff during heavy rainfall as opposed to allowing the water to soak into the land. Detergents are used for cleaning and this is allowed to run directly onto the land. Food Waste During the visit food waste was dumped under a bush. Since then, compost heaps have been introduced for food waste. These compost heaps should be rotated annually and the compost used on the garden.
Waste sorting bins 50
Waste Water
Cristn water outflow
Human Waste Grass composting toilets are used at Cristin. After using the toilet users are advised to sprinkle some grass on their waste. This system is an appropriate solution for an off grid community, as flushing toilets would have a high water demand and produce larger quantities of waste to deal with. The grass composting toilet buckets are emptied daily into plywood pits where the waste decomposes. The plywood pits are not emptied and rot over time. This is less than ideal as a long term sustainable solution to dealing with human waste.
Human waste pits
6 • WASTE Soak away drains Where waste water is currently discharged straight onto the landscape, soak away drains should be implemented. Soak away drains can be as simple as a large hole dug into the ground that is backfilled with gravel/rocks and then covered with topsoil. Waste water then permeates slowly into the ground. If there is enough area, a constructed wetland would be the ideal solution for waste water management. This system would allow water to percolate into the ground and be filtered biologically whilst also providing habitats for wildlife.
Human Waste Composting Separating human waste into liquids and solids allows for it to be composted quicker and re used as a fertiliser. Solid waste can be composted and reused within a year for root vegetables or arable crops. Liquid waste can either be stored and diluted to form a liquid fertiliser or a constructed wetland can be used to filter and purify it naturally. Seperating human waste is best done when it is generated. Commercially available funnels can be used to separate solid from liquid waste. If this is not possible a storage system that filters liquid waste can be used as is shown in the diagram.
Constructed Wetlands The treatment of waste water by a constructed wetland can be split into three; primary, secondary and tertiary. At each stage the quality of water is improved. There are two types of constructed wetland; vertical and horizontal; each have varying merits and constraints. Vertical systems have a permeable substrate where water flows down into. Horizontal systems allow water to pass slowly along a surface - these systems resemble ponds. As reedbeds are already present on the island, the use of a constructed wetland for purifying water waste is a highly attractive solution.
Waste management options Waste should be viewed as a potential, not a problem. There is potential to reuse human and food waste to produce soil rich in nutrients. Water waste provides the potential for a constructed wetland that in turn improves biodiversity. Reducing rubbish and reusing/recycling is something we should all be trying to do. Encouraging those visiting the island to reduce the amount of waste they produce could be done by discouraging excessive food waste and excessive packaging from being brought to the island.
Raised Toilet
Wheelie Bin
Solid & Liquid Separation
Soak away drain
Solid waste composting bin
Solid waste filtering bin. 51
7 • CONCLUSION Summary It is hoped that the report has provided a comprehensive analysis of Cristin and its associated systems for water, energy and waste. We hope some of the recommendations outlined in the report will be acted upon and developed to form a more secure and sustainable support base for the Observatories work. The key points of assessment and recommendations are outlined on the following two pages.
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Fabric • Heat is lost through the un-insulated walls, windows and infiltration at Cristin. • Improving air tightness and thermal performance will have a range of benefits, most importantly reducing running costs. • Cristin’s listed status provides challenges. These challenges are not prohibitive.
Fabric • Air tightness should be improved by sealing services penetrations and where windows and doors meet their frames. • Thermal performance should be improved through secondary glazing, roof and floor insulation and internal wall insulation.
Water • There are concerns about the consistency of water quality provided at Cristin. • The storage system is in need of maintenance in the short term. • Rainwater although utilised could be used and distributed more strategically.
7 • CONCLUSION Water • As a short term solution water tanks should be painted black and then white to reduce light ingress and heating. • A new system should be specified with new tanks that will not allow any light in. • A range of water purification and treatment options should be assessed, including chemical treatment, sediment filtration and UV treatment.
Energy
Energy
Waste
• The current use of fossil fuels is unsustainable and costly. • There is huge potential to reduce the amount of fossil fuels used at Cristin. • The systems have grown sporadically where demand was needed, a more centralised system would improve efficiency • A target should be set for zero fossil fuel use at cristin.
• A range of technologies should be explored for reducing fossil fuel use. • Solar PV will reduce the generator demand as well as a proportion of gas and burning oil demand. • Solar thermal in conjunction with PV could further reduce burning oil demand. • Wind power in conjunction with Solar PV could produce enough energy to eliminate all burning oil through the use of heat pups and eliminate gas use through electric ovens and fridges.
• Management of human waste is poor throughout the island. • There is potential to utilise food and human waste on the island for compost and fertiliser. • Separating solid and liquid human waste makes it easier to deal with. • Although all rubbish and recycling is removed from the island visitors could be advised to produce less waste. • Anaerobic digestion and or constructed wetlands could be used to treat waste and produce usable by-products.
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EWB UWE Bardsey Island Audit Report 2013/14