The Sustainable Gas Institute’s third White Paper reviews evaluates the overall potential for decarbonising the gas network, including the use of biomethane and hydrogen in existing gas infrastructure. Download: http://www.sustainablegasinstitute.org/a-greener-gas-grid/

1. A greener gas
grid: What are
the options?
20th July 2017
Jamie Speirs
Sustainable Gas Institute
www.sustainablegasinstitute.org/
twitter.com/sgi_London
sgi@imperial.ac.uk
Be social! Use #GreenGasGrid

2. Context: Existing Gas Network
• Valuable asset
• Provides system benefit:
flexibility
• The higher pressure
stages of this network
will likely remain for
some time
• The low pressure local
distribution network may
not
Based on UK gas network

3. Context: The Problem
• There are emissions associated with natural gas including supply chain
• Ambitious carbon targets place pressure on these GHG emissions
• Many scenarios therefore choose less gas in future, often in favour of electricity and
electric heat pumps
• However, gas deals with daily and seasonal flexibility well, consumers are familiar with
it and many buildings are difficult to heat with electric heat pumps

4. Aims and scope
• What are the options for decarbonising gas
networks including:
• Technical potential;
• GHG emissions;
• Costs; and
• How do these options compare to electricity
and heat pumps?

5. Evidence Review Methodology
Systematic Review of
Literature
• Systematic
• Replicable
• Robust
Expert Panel
• Wide Range of experts
• Academia, industry,
government, third sector
• Provide guidance on
scope
• Provide review of
emerging analysis
Final Report
• Analysis of evidence
• Accessible, written for
non-expert audience

6. …for the rest of this presentation…
• Key Findings
• Options to Decarbonise the Gas Network
• Costs of Decarbonised Gas Network Options
• Greenhouse Gas Emissions from Decarbonised Gas
• Conclusions

7. Key Findings
The Benefits
• There are a number of options to significantly reduce GHGs in gas networks
• The benefits include:
• Low cost flexibility, low impact and costs to consumers, similarity to the existing
system
The Uncertainties
• Costs of decarbonised gas options are uncertain, will be more expensive than natural
gas, but compare more favourably to electricity and heat pumps.
• GHG emissions are also uncertain and estimates vary significantly
The Challenges
• GHG emissions are significantly lower than current gas system, but often higher than
low carbon electricity and heat pumps.
• There is a need for more evidence, particularly on the safety of hydrogen in existing
gas networks

8. Options to Decarbonise the Gas Network

9. Options: Hydrogen
Hydrogen can
be converted
to methane

10. Options: Biomethane
Wet biomass
Dry biomass
Anaerobic
digestion
Gasification
Biomethane
Hydrogen Methanation

11. Impact on gas system
Biomethane
• Biomethane production plant,
including upgrading/purifying/
methanation
• Connection to the gas network
• Rest of network largely prepared,
including consumers
Hydrogen
• Hydrogen production plant needed
• Connection to existing network needed
(national and local transmission)
• Upgrades to existing low pressure network
(IMRP)???
• Consumer conversion

12. Gas demand: SMR and CCS
We will need more gas

13. Costs of Decarbonised Gas Network Options

14. Costs: Hydrogen and
Biomethane production

15. Costs: pipelines and storage
Cheapest types of
electricity storage >
£100/kWh
Cost of upgrading existing
low pressure network for
hydrogen may be very low
~£10,000/km

16. Retail price of gas
Includes
• Cost of gas
production plant
• Cost of network
improvements
• Cost of network
access
• Costs of storage
• Vat and other levies
(UK)
• When comparing
heat the appliance
efficiency becomes
very important

17. Greenhouse Gas Emissions from
Decarbonised Gas

18. GHG emissions: hydrogen

19. Emissions from SMR with CCS
At highest CO2 capture rates and
lowest supply chain emissions
hydrogen from SMR with CCS
approaches total GHG emissions

20. The importance of
supply chain emissions
• Supply chain emissions are increasingly important as the
emissions from gas production are reduced
• However, not yet well represented in the evidence
• The supply chain emissions for hydrogen production from
SMR with CCS and electrolysis are very important due to
low emissions in hydrogen production.
• Biomass gasification characterised by large negative
supply chain emissions and large positive hydrogen
production emissions. Small percentage improvements in
biomass gasification emissions could therefore have
relatively large impact on total emissions.
SMR + CCS
Supply Chain: 37 to 41
H2 Production: 40 to 77
Electrolysis
Supply Chain: 25 to 178
H2 Production: 0
Biomass Gasification
Supply Chain: -786 to -288
H2 Production: 571 to 786
Units: gCO2eq/kWh

21. Findings (again)
The Benefits
• There are a number of options to significantly reduce GHGs in gas networks
• The benefits include:
• Low cost flexibility, low impact and costs to consumers, similarity to the existing
system
The Uncertainties
• Costs of decarbonised gas options are uncertain, likely to be more expensive than
natural gas, but compare more favourably to electricity and heat pumps.
• GHG emissions are also uncertain and estimates vary significantly
The Challenges
• GHG emissions are significantly lower than current gas system, but often higher than
low carbon electricity and heat pumps.
• There is a need for more evidence, particularly on the safety of hydrogen in existing
gas networks
• In future a balance of gas and electricity vectors may be needed
take advantage of their respective benefits.
• More research needed to understand these trade-offs better

22. Acknowledgements
Authors: Jamie Speirs, Paul Balcombe, Erin Johnson, Jeanne Martin, Nigel Brandon and
Adam Hawkes
The Expert Panel,
Chris Andreou (National Grid), Philip Cohen (Department of Business, Energy and Industrial
Strategy), Paul Dodds (University College London), David Joffe (Committee on Climate
Change), Stephen Marland (National Grid), Dan Sadler (Northern Gas Networks) and Goran
Strbac (Imperial College London).
Special thanks to
• Phil Heptonstall (Imperial College London)
• Zara Qadir (SGI)
• Jeff Edwards (Shell)
• And the rest of the SGI Team: Kris Anderson, Sara Budinis, Ivan Garcia Kerdan, Sara
Giarola, Chris Jones, Julia Sachs, Quasirat Hasnat

23. Thank you for your attention
Download the full White Paper 3 and the Briefing Note at:
http://www.sustainablegasinstitute.org/A-Greener-Gas-Grid
Dr Jamie Speirs
Lead: SGI White Paper Series
Sustainable Gas Institute
www.sustainablegasinstitute.org/
twitter.com/sgi_London
sgi@imperial.ac.uk
Be social! Use #unlockCCS

24. Back-up slides

25. Retail price per unit of heat

26. Emissions from Electrolysis
Remove

27. Resource implications:
Electrolysis

28. Hydrogen Conversion Costs

29. Decarbonised
gas network options
Low carbon gas
Hydrogen Biomethane
Reduce methane use
Blending (up to 20% vol)
Hybrid heat
pump
Gas fired
heat pumps
100%
How much can this achieve?
Already
doing
this

30. Methane
MethanationElectricity Electrolysi
s
Hydroge
n
Coal
Dry
biomass
Gasificatio
n
Wet
biomass
Anaerobic
digestion

31. Countries that use gas networks
• A number of
countries have
very developed
gas networks
• Most evidence
comes from
these countries
• Less well
networked
countries may
develop in the
future