Task 37 - UK Experience with Gas Grid Injection

Task 37 Energy from Biogas conference Cork

UK Experience with Gas Grid injection

15th September 2011 John Baldwin CNG Services Ltd john.baldwin@cngservices.co.uk www.cngservices.co.uk 07831 241217

UK Experience with Gas Grid Injection • • • • • • • • • • • • •

CNG Services Ltd Didcot Biomethane Project Adnams Biomethane Project Biogas clean-up and upgrading Gas Enrichment BtG Plant Connection Pipeline and Contracts with Gas Distribution Networks Ofgem Review Process Oxygen Economics Green Gas Certificates Market Forecast Biomethane Conclusions

CNG Services Ltd • Cleaning bio-gas and injecting biomethane into the gas grid – – – –

Creator of the UU Davyhulme BtG and CBM Project Developer of Didcot project for Thames Water, SGN and Centrica Consultant on Adnams Project Working on 8 further BtG Projects in UK

• CNG Filling Stations – Supporting CNG/CBM vehicle development – VCNG-LNG virtual pipelines – LNG for vehicles/off-grid energy consumers

• Supporting development of onshore gas and storage projects – Ryedale Gas Project – Wingas Saltfleetby – Halite Preesall We are independent from all makers of plant, vehicles, clean-up, compression....our aim is to support developers in projects which are gas engineering based but a bit complicated.....

BG Group Kazakhstan • We commissioned in July 2010 the first CNG filling station in Kazakhstan • 200 buses ordered for Asian games • CNG is the solution to air quality (not one CNG bus in UK due to Bus Service Operators Grant (BSOG) which makes CNG uneconomic for buses in UK)

Most major cities have air quality problems and so make CNG the fuel of choice for buses.......we should have CNG buses in UK, we have very few

Crewe CNG Station • We have re-opened our Crewe CNG station in August • Filling 5 CNG dual fuel trucks for GIST/M&S • http://www.youtube.com/watch?v=orxBtoXyjos

Largest grid supplied CNG station in UK – takes gas from 4 bar grid and so uses 20% less electricity compared to 0.5 bar grid

Biomethane Injection - Didcot

Didcot biogas was flared, now used to heat Didcot homes

Process Overview for Gas Injection into Grid at Didcot

Biomethane

Biogas Clean-up and upgrading Plant

Biogas

Didcot – UK’s First BtG Project

Digesters

Propane Storage Gas bag Propane Injector

Telemetry Energy & quality Measurement

CSL – Designer and Project Manager H2S and Siloxane filters

Biogas upgrader

Flow of biogas - 100 m 3/hr First gas to grid on 3rd Oct 2010

Site Location

Connection to Gas Network

Location of New Plant

9

Residential Area that will use new gas supply

Process Flowchart Raw Biogas AD

Gas Bag

63% CH4 34.5% CO2 0.3% O2 2% N2

Waste Biogas Flare

120 scmh Biogas Clean Up Process Plant

Out of Spec Biomethane

Propane Injection Biomethane 98.2% 0.3% 1.5%

Network Entry Valve (ESD)

CH4 O2 N2 Biomethane To Grid Equipment

Existing Gas Network

Network Connection Valve

Filters for Siloxanes and H2S

Water Wash Process Plant

Site Layout

Propane Storage and Blending Plant

Gas Analysis equipment

Biomethane to Grid Plant

Adnams – BioGroup – the UK’s first BtG Food Waste Project

CNG Services is providing design and other consultancy related to the injection of gas into NTS and biomethane sales

Food Reception Hall, Clean-up, Upgrading and BtG Plant

Food Reception Building BtG Compound

GTS Plant (cryogenic CO2 removal)

Biogas Clean up and Upgrading Technology Summary

Biogas Composition

• • • • • •

Methane 55 - 60% CO2 35 - 40% O2 0.1 – 0.5% N2 0.5 – 2% H2S 200 – 2,000 ppm Siloxanes (sewage biogas)

H2S and O2/N2 important Aim is to remove H2S, CO2 and dry the gas

Water Wash

• • • • •

99% of biomethane to grid, 1% methane slip Can recover heat from larger plants (from compressor cooling water) 14 m high Removes H2S and siloxanes Simple plant, as Didcot, likely to be lowest cost option at <500 m3/hr

Chemical Absorption

• 99.8% of biomethane to grid, <0.2% methane vented • Needs significant heat to raise steam regenerate the chemicals (around 10% of biogas energy) – can often recover most of this • Ideal if waste heat already available • Requires less propane • Less electricity if 2 bar grid

Pressure Swing Adsorption

• 92% of biomethane to grid, 8% of methane goes with the CO2 • This gas can be flared or burnt in CHP or boiler (but needs to be brought back to 33% methane) • No methane vented • Similar electricity to water wash

Membrane Separation

• • • •

Few membrane plants Similar electricity to PSA Similar issue to PSA in giving an ‘off-gas’ with 5 - 10% CH4 May be a good technology if can reduce CH4 in off-gas...

Cryogenic Upgrading

• North Morecambe gas with 10% N2 uses this technology • Appears to be a good technology, but not yet fully proven for biogas applications • Liquid CO2 attractive for use as refrigerant

EU Experience of Biogas Clean-up and Upgrading

• Task 37 Report: • 42 Water Wash • 36 PSA • 23 Chemical Wash

• CSL staff have visited around 10 such plants including >500 m3/hr for each technology

Gas Enrichment

Propane Enrichment Propane Storage tanks

Propane Mixing Vessel

• The Gross Calorific Value (GCV) in the GB gas grid is around 39 MJ/M3 • The typical biomethane GCV is 37 MJ/M3 • Propane has to be added to bring the CV up to 39 MJ/M3 • This is because of billing for natural gas

BtG Plant

Biomethane to Grid (BtG) â&#x20AC;&#x201C; Equipment and Regulations Network Entry Plant must have:

Regulation Requirement

Gas Quality Measurement

GS(M)R Reg 8 Schedule 3 pt 1

Gas Flow weighted average CV to measure/record the energy of the gas

OFGEM Direction under the 1996 Gas (Calculation of Thermal Energy ) Regs

Volume Flow Measurement to enable calculation of gas quality

GS(M)R

Pressure Control of gas delivery into network

GS(M)R & PSSR

Stenching Agent injection

GS(M)R Reg 8 Schedule 3 pt 1

COMPLIANCE -Telemetry to monitor & record to Gas Control Centre SHUTDOWN - Emergency Shutdown System (ESD)

BtG Plant • The BtG plant is located after the Clean-up and Upgrading Plant and before the connection pipeline to the gas grid • BtG Plant comprises the following: • • • • • •

Odorant storage and injection Gas quality monitoring Gas CV measurement Gas flow measurement Pressure control Telemetry

Next slides show the major components

Odorant Plant

Odorant injection system

Gas Metering & Pressure Control Equipment

Accurate flow measurement

Pressure control â&#x20AC;&#x201C; entry into 2 bar MP

Gas Quality and CV Measuring Equipment • Key considerations that the project had to recognise were: – Charge to Consumers – Safety of Gas – Maintain network integrity

CV H2S & Wobbe Number Water dewpoint & Oxygen (internal corrosion)

• Monitoring and CV measuring costs over £300k – – – – –

Currently only one Ofgem approved device (Danalyser) Siemens Microbox (FWACV hardware) Total sulphur & H2S measurement (MAXUM) Hydrocarbon dewpoint measurement High Pressure Metering Information System (HPMIS)

Gas Quality and CV Measuring Equipment (2) SGN as the gas transporter were Directed

by OFGEM to use an approved type Danalyser ( Gas chromatograph) that enables highly accurate sampling.

Accurate to around 0.14 MJ/M3 (less than 0.4% error) Accepted that this is an expensive solution but there was no alternative for Didcot 2010

700 Series Danalyser

Fast Acting Gas Sampling and Shut Off (ESD) Equipment

Fast acting gas quality sampling equipment

Emergency Shut Down System

Connection to Gas Grid

Connection to Gas Grid

Capacity in the Gas Grid • Often the gas grid cannot accept the biomethane on a 365 day basis – CSL believes an issue around 30-40% of the time Expected Minimum Hourly Injection Rate (Overnight) Expected in the Driffield Area Based on Standard Load Duration Curves 1000 900 800 700

scm/h

600 500 400 300 200 100 0 Jan

Fe b

Mar

Cold Profile

Apr

May

Jun

Ave rage Profile

Jul

Aug Warm Profile

Se p

Oct

Nov

Dec

Required Input

• Solution is compressors within the grid (to export gas from one pressure tier to the higher pressure one that feeds it) – CSL developing a pilot project for NG/NGN

National Grid Feasibility Study

Contracts with Gas Distribution Network

Network Entry Agreement • NEA needs to address capacity – NTS NEA has no relevance to capacity which is covered in Uniform Network Code – Links to GDN incentives, obligations etc.

• NEA needs to address liabilities if the GDN provides some services such as odorant addition or gas quality monitoring • NTS NEA has concept of Daily Flow Notifications where NTS informed continuously of flow forecasts – For biomethane likely to be unmanned sites – Key is that the GDN network is not impacted if biomethane flows stop – Until there have been a number of projects it may be that GDN System Control want information even though they do not use it for any purpose – The biomethane system flows must be monitored by computer with no need for manual intervention

• NEA Links to Biomethane Sales - the gas purchaser also requires forecasts to allow them to stay in balance – Materiality point as flows very low – Unmanned sites, gas flows should be steady with changes only due to plant malfunction

Design and Build Agreement • • • • • •

What plant is built?

What level of reliability/redundancy?

Liabilities for failures/standards of service Who pays for it?

Who maintains it?

These are all issues that are being resolved in an Ofgem led Review Group….see next slide

Ofgem Review • Ofgem are leading an industry wide review to establish consensus in relation to a number of key issues: – GDN Connection Policy/ownership for Biomethane Projects (see next slides) – Capacity for Biomethane – Technical standards associated with Calorific Value measurement for biomethane flows – Gas Quality Analysis at Biomethane entry – Transmission of data to the GDN's agent (Xoserve)

• First meeting on 27th Sept 2011 • Aim to complete by end 2011

BtG Ownership and Liability Options (1) • Option 1 Biomethane producer funds, GDN owns and maintains, no RAV/return to GDN, GDN takes limited liabilities for plant performance – This is the existing policy of the GDNs and needs Ofgem consent to change it – Duplication of engineering and construction and work has to be done by biomethane producers and by companies on the grid company approved vendor list

• Option 2 GDN funds the plant, owns it, receives a return and takes appropriate liabilities – This is similar to the German model (75% GDN, 25% customer funding), high capital cost, more redundancy – GDNs have made a proposal to modify the way that biomethane projects pay transportation charges (helpful development)

BtG Ownership and Liability Options (2) • Option 3 Biomethane producer funds, owns and operates having to meet GDN’s specification: – This is the Dutch model for biomethane and allows the producer to set level of redundancy (if they need 100% reliable, need more plant, higher cost) – Producer can appoint single contractor for design and build of cleanup, upgrading, propane, BtG, pipeline with lower overall costs and clear accountability for safety and project programme – The Dutch include an insurance scheme with this option

Oxygen • GS(M)R limit is 0.2%, the industry needs 1% (ideally 2%) • Usually no blending option (as at Didcot) • Key issue is corrosion if there are metal mains and the grid is wet • At present HSE may grant an exemption based on individual risk assessment in each case • HSE have reviewed Oxygen content in respect to GDN networks and are believed to be content to change specification to 1% subject to some additional data from GDNs • Hopefully, move to 1% in 2012

Economics

Renewable Heat Incentive (RHI) • 6.7 p/kWh • This is on top of value of gas – around 2 p/kWh • Energy that can claim RHI adjusted: – First remove propane energy – Next, remove energy from external sources used to heat the AD

• Tariff fixed for 20 years, increases each year with inflation • The RHI gives broadly similar project returns to the electricity option RHI is attractive if there is no local use for waste heat

Electricity Feed In Tariff or ROCs • Biogas that generates electricity can an electricity Feed In Tariff (FIT) • For plants >500 kWh , FIT worth 9 p/kWh on top of the normal electricity price (which is around 4 p/kWh) • Or biogas that generates electricity can earn double ROCs (Renewable Obligation Certificates) worth around £45/MWh for 1 ROC

Most existing ADs in UK (they are located at sewage treatment works) earn 1 x ROCs

Renewable Transport Fuel Certificates • • • •

Compressed Biomethane (CBM) earns 1 X Renewable Transport Fuel Certificates (RTFC) 1 x RTFC worth around 20 p per KG of CBM Under EU Renewable Energy Directive double RTFCs for transport fuel made from waste 40 p/kg still not as good as income from electricity or for grid injection

300 m3/hr gives around 1 MWh of electricity with FIT of around £600k 500,000 therms into grid = 1 million kg = RHI of around £700k 1 million kg of CBM has RTFC worth around £400k – so vehicles will not run directly on biomethane

Green Gas Certificates

Green Gas Certificate Scheme • Announced on 8 October 2010, system being built, formal launch was on 3rd March 2011 by Renewable Energy Assurance Ltd • Designed to allow ‘tracking of biomethane from injection point to customer” – Integrity - no ‘double counting’

• It is expected that the Green Gas Certificate will be bought by the gas purchaser and not sold separately • Allows the gas purchaser to work with the producer to market biomethane to customers

GGCS Launch Members • • • • • • • • •

National Grid British Gas Eon Thames Water (Didcot) Adnams Biogroup (Adnams) Milton Keynes City Council CNG Services Ltd System built that will allow the system to operate http://www.greengas.org.uk/

AD Developer – Gas Supplier – Gas Grid – Gas Consumer Green Gas Certificate Scheme

Gas can be used in CHP, in vehicles, in fuel cells, any use possible

Gas Consumer Sale of ‘green’ therms

Gas Supplier

Purchase of biomethane therms

Normal grid gas

Clean-up plant and grid injection

Gas Distribution Network Inject gas into grid

AD Developer Organic material Processing via Anaerobic Digesters

Market Forecast •

The are 5 main sectors: • Agricultural • • •

• • • •

Waste Animal manure Crops for Energy

Commercial food waste Biodegradable waste (local authority garden/food waste) Sewage sludge Landfill

It is possible that there will be 40 BtG projects in UK in period to 2014

Biomethane Conclusions • • • • • •

Biogas should only generate electricity when all the heat can be used UK has advanced gas grid and the full support of UK gas distribution network owners and energy suppliers UK gas production declining, we need to find new gas resources to supply domestic customers and improve security of supply Biomethane injection into gas grid is widespread in Europe, no material technical issues 10% of domestic customer gas supply by 2020 is a reasonable target Green Gas Certificates offer opportunity to keep gas into new homes which has to make a lot of sense and also to fuel dual fuel CNG-diesel trucks Now that RHI has been introduced at a reasonable level, the market for biomethane can start to develop in the UK