1. Biomethane Review of UK activity
Alan Midwinter
SGN Project Manager 29th September 2011
Wardell Armstong LLP

2. Who are SGN? Scotia Gas Networks –
Formed in June 2005 following the acquisition of two gas distribution networks from National Grid (Scotland and South of England)
Owns and operates the second largest gas distribution network in the UK.
Serving over 5.8 million customers 2

3. Why gas networks here? DECC 2050 Pathways Study
Demonstrated that substantial electrification of heat and transport is required in order to meet 2050 Targets (80% GHG emission reduction)
What is the future for the gas networks ?
ENA Gas Futures Group commissioned Redpoint to develop future gas scenarios to 2050 and beyond :-
Retaining gas infrastructure could be up to £700bn cheaper to UK plc than a complete electrification solution
Require low carbon renewable gas (BIOGAS) for Bio-methane
Potential for Bio-methane injection - 50% of UK domestic heating load
DECC output targets for bio-methane are 7TWh p.a. by 2020 and could extend to TWh per annum of renewable gas by 2050 3

4. Gas Futures Redpoint Pathways involving significant
Biomethane to Grid Injection
Green Gas
Gas Versatility

5. ‘Green Gas’ Incentive 5

6. Low Carbon Energy - Biogas
UK produces 16 million tonnes of food waste (8 million tonnes from households) and 90 million tonnes of animal waste annually with the majority going to landfill.
Organic material degrades producing methane gas, 23 times more damaging to the environment as a greenhouse gas than carbon dioxide.
EU landfill directive obliges local authorities to send less biodegradable waste to landfill, generating requirement to recycle or reprocess.
Anaerobic Digestion (AD) is a waste treatment process for organic waste, recovering energy from waste in the form of biogas (50% to 65% methane)
Biogas traditionally has been used for Electricity generation but can be cleaned for Biomethane injection or used as CNG for vehicle fuel. 6

7. Government Incentives
UK Government is committed to meet Greenhouse Gas Emission targets
15% reduction by 2020
80% reduction by 2050
Landfill taxes – increasing to £80 per tonne.
Energy recovery potential for AD could support 2,100 AD plants (50,000 t) will be required.
The Government has incentive schemes for the use of Biogas as a low carbon energy
Existing incentives FIT’s & ROC’s for electricity generation
RTFO’s for vehicle fuels
Government has now incentivised a scheme that will for the first time provide long-term guaranteed financial support for renewable heat installations
Renewable Heat Incentive (RHI)

8. RHI & Bio-methane Injection
Introduction of the RHI (July 2011) provides a sound economic pathway for gas injection into the grid, financially attractive above 500 m3/h bio-gas (300 m3/h biomethane).
Bio-methane RHI tariff is currently 6.8p / kWh
20 year tariff to include capital cost for all plant
Degression of RHI tariff will feature once target volume is reached
Bio-methane injection is 50% more efficient than electricity only applications
Important contribution to a stable and reliable energy supply 8

9. Comparative Income
£/m
Biogas Plant Capacity m3/hr 9

10. Didcot - The Objectives10

11. Project time-line SGN commissioned Feasibility study in April 2009
Project Approval April 2010
3 October 2010 SGN, working with our partners, Thames Water and Centrica, delivered the first Bio-methane gas to Grid in the UK
Update output to capacity and schematic
The UK Government in conjunction with the rest of the European Union want to deliver 15% of energy from renewable sources by 2020
methane the main component in natural gas is 21 times more harmful to the atmosphere than CO2
it is acknowledged that if waste methane can be harnessed to produce energy, then this would go part of the way to meeting the national targets.
As a business SGN realised that the world of Biogas was a real economic and socially responsive opportunity and that we wanted to be a stakeholder in the future of AD development.
There is a belief that up to half of the UK’s domestic gas ( xxx ) could be produced from biogas and in the process up to 10,000 jobs could be created.

12. Key Objectives
SGN used Innovation Funding to deliver a number of important objectives:
Understand Legislative and Regulatory issues
Improve understanding in relation into gas quality (Oxygen and siloxanes in particular)
Understand the impacts of bio-methane on the operation and configuration of the local gas network
Prove biogas clean-up and upgrading technology in the UK
Provide a ‘base-line’ for gas quality monitoring and associated equipment from which lower cost options could be developed
Share Project learning and improve efficiency to the benefit of future schemes
Read Slide Content

13. Regulatory Requirements
Safety (HSE)
Transporters may only Transport gas that complies with provisions of Gas Safety Management Regulations (GS(M)R)
Gas Transporters are obliged (by the Regulations) to take sufficient measures to confirm that gas is compliant or must not allow gas to flow
Commercial (Ofgem and the Uniform Network Code)
The bio-methane must have its energy measured in compliance with Gas Thermal Energy Regulations
The processes must comply with appropriate UNC arrangements

14. Gas Quality Baseline
Establish Biogas composition and available flow-rate
Ensure the local SGN Network could accept the volume of gas that will be produced on a 24/7 basis
Establish biomethane gas quality requirement, specifically around :
Oxygen
Siloxanes
Calorific value
Identify appropriate biogas clean-up and upgrading technology for Didcot

15. Key Objective Outputs Oxygen content could potentially be up to 2%
HSE derogation would be required for >0.2%
Siloxanes were likely to be present in the biogas
Additional filtration equipment would be required
The calorific value from the bio-methane would be lower than the existing network values
Enrichment with propane would be required
Costs were likely to be high – SGN IFI Funding used
The project could be implemented in 2010 and would therefore provide valuable learning ahead of RHI introduction in 2011

16. How can AD Biogas become Bio-methane
Bio-gas from an anaerobic digester contains typically
Natural gas contains around 90% methane, with ethane, propane, butane, CO2 and nitrogen making up the rest.
To inject Biogas into the gas grid it is necessary to clean it and upgrade it to biomethane
Bio- methane is around 98% methane content
Methane = 55 – 65%
CO2  = 35 – 40%
O2 = 0.1 – 0.5%
N2 = 0.5 – 2%
H2S = 200 – 2,000 ppm
Siloxanes (sewage only) 16

17. The Didcot Project

18. Didcot Project – Before injection (April 2010)
Digester Gas Bag Flare 18

19. Why Didcot ?
Existing Sewage Treatment Works with 2 Digesters producing sufficient waste biogas
Thames Water interested in the SGN proposition to clean up the biogas, upgrade and inject into
the local SGN grid
Practical details:
Resilient local Network within 400m of site
Available space
Unlikely to have issues with planning authorities

20. Didcot – The ‘GREEN’ Gas process
Biomethane
Biogas
Biogas Clean-up and upgrading Plant

21. Residential Area that will use new gas supply
Site Location
Connection to Gas Network
Residential Area that will use new gas supply
Location of New Plant
SGN decided to develop a plant to make bio methane to grid a reality, selected Didcot with Partner Thames Water
Thames Water had an existing digester where excess biogas was being flared off as waste.
The flows were low and therefore allowed for development and learning on what was an unknown entity in the UK.
The local gas grid was relatively local and predominantly plastic and injection pressure was ideal.

22. Biomethane – The ProcessAD AD
Electricity Output
Typical Bio-gas
60-65% CH4
34-36% CO2
1% O2
Gas Storage
Gas Engines
Flare
CO2
Bio-gas Clean
Up Plant
(Water Wash)
Filters
Out of Spec Bio-methane
Bio-methane
97-98% BioCH4
0.3% O2
Propane Upgrade
Network Entry Valve (ESD)
Bio-methane to Grid Entry Equipment
(Network Entry Assets)
Existing Gas Network
Network Connection 22

23. Site Layout Filters for Siloxanes and H2S Water Wash Process Plant
Propane Storage and Blending Plant
Gas Analysis equipment
Biomethane
to Grid Plant

24. Didcot Project (Apr – Oct 2010) First Biomethane to grid plant in UK
DIGESTERS
GAS STORAGE
UPGRADE PLANT - PROPANE
TELEMETRY
CUSTODY TRANSFER STN
CLEAN UP PLANT 24

25. Biogas Clean-up and Upgrading Equipment
Established Water scrubbing technology
Removes CO2
Removes H2S
Removes most siloxanes
Dries the biogas
Additional filtration to ensure no siloxanes enter network
H2S captured when it is removed from the water and not vented to atmosphere

26. Propane Enrichment Propane Tanks refilled by Tanker every 3 to 4 weeks
Propane Storage Tanks
Mixing Vessel
Industry Review Group (GDNs, shippers, REA, Ofgem)
Sept-Oct 2010 agreed that adding propane to meet FWACV was necessary to ensure customers were not being disadvantaged by bio-methane injection

27. Biomethane Injection – Equipment and Regulations
Gas Transporter must ensure : Regulation Requirement
Gas Quality Measurement GS(M)R Reg 8 Schedule 3 pt 1
Pressure Control of gas delivery into network GS(M)R & PSSR
Stenching Agent injection GS(M)R Reg 8 Schedule 3 pt 1
Volume Flow Measurement GS(M)R & Gas (Calculation of Thermal to enable calculation of gas quality Energy ) Regs
Gas Flow weighted average CV to OFGEM Direction under the 1996 Gas measure/record the energy of the gas (Calculation of Thermal Energy ) Regs
To facilitate entry into a gas network the facility must ensure that the gas entering the network is in compliance with UK legislation and provide enough information to satisfy the gas transporter that sufficient measures are in place to CONFIRM that the gas entering the network is COMPLIANT to enable the Gas Transporter to discharge their duties within GSMR.
If the gas is out of ‘GSMR tolerance’ the gas transporter is obliged to ensure that any out of specification gas is prohibited from flowing into the gas network.
COMPLIANCE -Telemetry to monitor & record to Gas Control Centre
SHUTDOWN - Emergency Shutdown System (ESD)

28. Gas Network Considerations
Key considerations that the project had to recognise -
Charge to Consumers CV
Consumer Safety H2S & Wobbe Number
Network Integrity Water dewpoint & Oxygen (internal corrosion)
Existing Constraints
Currently only one OFGEM approved device (Danalyser)
Siemens Microbox (FWACV hardware – supervisory software)
Total sulphur & H2S measurement (MAXUM)
Hydrocarbon dewpoint measurement
High Pressure Metering Information System (HPMIS)

29. HSE - GAS SAFETY – GS(M)R Fast Acting and Shut Off ( ESD)
Fast acting gas quality
sampling equipment
(H2O, H2S, S, CV, H2, O2 , etc)
Emergency Shut Down System

30. GAS SAFETY – Stenching Agent
Odorant injection system

31. GAS SAFETY - Pressure Control & Metering
Accurate flow measurement
Pressure control – entry into 2 bar MP 31

32. OFGEM - Thermal Energy
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

33. Completed Project (1) Digesters Propane Storage Gas bag
Propane mixing and injection
Thames Water control room
H2S and Siloxane filters
Energy and quality Measurement, odorant addition, telemetry to Gas Control Centre
Biogas clean-up and upgrading plant 33

34. Project at Completion
Note the reason that planning consent was not perceived to be a problem – Didcot A station – coal fired generation in background – due to close in sometime during 2012.

35. Project at Completion (2)
Some photos of the finished plant
Admire the irony of Didcot power station in the background – it only reinforces the possibility in these times for the need to secure renewable energy wherever possible

36. Project at Completion (3)

37. Project Learning

38. Successes – All in it together!!
Co-operation of Regulatory Bodies
HSE Positive support for 2% Oxygen exemption
OFGEM Timely Letter of Direction
- Expedited verification of Danalyser and other directed equipment
Single Party Delivery
of Project
SGN lead project delivery as principle contractor supported by our technical partner CNG Services Ltd
Excellent H&S record on congested site
Significantly reduced construction period
Modular Construction
HSE - It is a known fact that ferrous pipes will corrode if there is moisture and oxygen present.
We were therefore required to undertake close sampling of gas within the network to establish firstly that the existing network was dry and subsequently that it remains dry.
We undertook a substantial survey of all metal pipes in the network, network analysis of the predicted spread of biogas at raised oxygen levels and submitted this to the HSE
Sampling is still being carried out and results to date have surprised us with Oxygen levels of 0.3% in the biogas and only slightly more in the bio methane, further sampling will continue to validate this.
Output of the Technology
Bio-methane quality of clean up plant established
Propane requirement less than anticipated

39. Learning Location of Anaerobic Digestion - near gas grid
Capacity of the gas grid must be able to support facility
Operating pressure (IP or MP best)
Clean up technology and AD must be designed together to meet gas and energy quality requirements – retrofit process performance difficulties
Income balance between CHP (Fit’s) and grid injection (RHI) is attractive
Network Entry Agreements – Must be appropriate
Measurement
Telemetry
Nominations – link to gas sales
Communication
Design and Build Agreements – need industry standard
Maintenance
Ownership and Responsibility for Plant
Plant Redundancy / Availability 39

40. Future Challenges for Bio-methane Injection

41. Technical Challenges for Biomethane Injection
Technical barriers to Biomethane growth in UK
Oxygen content / specification - GS(M)R – is it appropriate at 0.2%?
CV enrichment with propane – not seen as green
Cost - Gas Quality / Thermal Energy equipment
Regulations and systems are designed for large volumes of gas.
GSMR data duplication - clean-up and network entry plant.
Increase diversity of suppliers for network entry systems
Network Entry Agreement
Historically designed for large facilities, need to be reflective of smaller biomethane sources.
Network Capacity Constraints
Capacity re-engineering and suitable models to facilitate biomethane entry
Gas Transporters Licence exemption
Class Exemption from section 6A of Gas Act for Biomethane 41

42. Future Challenges for Biomethane Injection
Socio-economic barriers to Biomethane growth in UK
Clarity on ownership and funding for network entry equipment.
Incentives for GDN’s within next Price Control Period?
RHI degression from 2012 ?
Feedstock suitability – varied feedstock contaminants / landfill gas 2012 ?
Project Funding – (Energy from Waste AD facilities)

43. Conclusions
Bio-methane could supply up to 50 % of domestic gas load here in the UK.
Bio-methane into the Gas Grid is far more efficient than into the electricity grid providing a sustainable gas supply
2020 UK Government target - generate 15% of national energy requirement from renewable sources
The Gas networks currently have the infrastructure to deliver this energy supply to the majority of our consumers .
Bio-methane injection is the best way to supply this low Carbon energy into millions of homes and businesses

44. Alan Midwinter alan.midwinter@sgn.co.uk www.sgn.co.uk
The potential is huge…..
Thank you
Alan Midwinter
The potential is huge…