Gas system in transition: Security of Supply consultation response

Future Energy Networks (FEN) represents National Gas, Cadent Gas, Northern Gas Networks, SGN and Wales & West Utilities and Northern Ireland associate members (Evolve Networks, Gas Networks Ireland, Kinecx Energy, Mutual Energy, Phoenix Energy).

We welcome the opportunity to respond to this consultation on security of supply as the first of what we hope to be a detailed and thorough “gas system in transition” review. Gas networks fully support the net zero transition and can play an active role in delivery of decarbonisation helping to manage costs, minimise disruption to consumers and enable economic growth. Effective utilisation of the gas networks can help to deliver net zero in a fair and affordable way, whilst maximising consumer choice and, crucially, maintaining resilience and security of supply.

While we welcome the government’s consideration of the gas system transition, we are concerned that the analysis in this consultation is too narrowly focused solely on gas and risks informing decisions which do not take into account the role of the gas infrastructure in the energy system as a whole. For example, statements on energy security benefits consider only the gas system and not a range of whole system scenarios, of which gas is one part. This approach needs fundamental review to ensure that decisions on gas system transition take into account impacts on the energy system as a whole.

Our approach to this consultation response and key messages

This consultation is primarily focused on upstream gas production and onshoring and storage of that gas production, rather than the midstream infrastructure which our members own and operate. However, clearly the overall security of supply of our gas system is of paramount importance to our members and their transportation infrastructure will play an absolutely pivotal role in ensuring gas security of supply over the coming years and through the energy transition.

We have not responded to the specific consultation questions but want to provide you with evidence as to the important role that our gas pipeline infrastructure must play in ensuring gas security of supply.

To that end, our response is framed around three key messages:

1. The role of gas in the energy system is changing and will change even more in the future, but that doesn’t automatically equate to a changing role for gas infrastructure during the transition. It is expected that total gas volumes (whether that be fossil gas or renewable gas) will decrease over time through the energy transition, but there is not a linear relationship between volumes of gas supplied and the infrastructure requirements to transport that gas. This fact should be central to strategic planning of our energy system and managing security of supply risk over the coming years. We must ensure both that there is sufficient investment in our gas infrastructure to maintain a robust level of security of supply and that we maximise the opportunities afforded by our world class, modern gas network. 
2. While a reduction in gas volumes is likely to be part of the journey towards Net Zero, a significant reduction in gas infrastructure should not be assumed to be the destination at the end of the transition. There is very strong and credible evidence to suggest that a widespread gas network transporting lower volumes of gas than today will be critical to a future energy system which meets our decarbonisation goals while keeping bills affordable and supplies secure. When viewed in this context, that puts a very different framing on how to address security of supply risks in the nearer term.
3. Low carbon gases should not be out of scope of this consultation as a means by which to mitigate gas security of supply risk. This is true for both green hydrogen and biomethane, particularly the latter where the technology has made a material difference to gas security of supply over the past 15 or so years.

We have also commented on one specific point raised in the consultation about a review of the Wobbe index.

Conclusion

FEN supports the need to ensure security of supply of gas through the energy transition. We note that this consultation, whilst part of the Gas System in Transition programme, is separate from the call for input on the transition and the future role of gas which is expected later this year from DESNZ. It must be ensured that the responses to both engagements are joined up so as not to create a fragmented view and conflicting or unnecessarily limiting decisions being made. We encourage a joined-up response from DESNZ once the Gas System in Transition programme has been completed.

Gas will remain a critical part of energy demand, powering industry and homes that cannot easily electrify and acting as a backup in times of peak demand to ensure electricity can continue to meet consumer needs. The transition to net zero sees a significant role for the gas networks in transporting gases to where they are most needed. Maximising the use of gas infrastructure will ensure security of supply and help to manage the costs of electricity grid upgrades whilst delivering investment, jobs and other income streams for rural communities, helping to support local growth and tackle climate change. 

FEN encourages the use of a whole systems approach with multiple energy vectors meeting energy demand. Supporting green gases and hybrid heating solutions can maintain resilience and security of supply, keep the cost of the energy transition low, deliver real carbon savings today and ensure more consumers can engage in the transition sooner.

FEN and our members are very keen to engage with DESNZ on this topic and the broader Gas System in Transition programme and would welcome dialogue outside of the formal consultation process through our senior leader industry working groups and bilaterals. Please contact myself or the team to progress this: james.earl@futureenergynetworks.org.uk / enquiries@futureenergynetworks.org.uk. 

Yours sincerely 
 
James Earl
Chief Executive Officer 
Future Energy Networks

Our Response in Detail

1. The role of gas in the energy system is changing and will change even more in the future, but that doesn’t automatically equate to a changing role for gas infrastructure during the transition.

FEN is an advocate for the decarbonisation of the energy system. We acknowledge that there will be a changing role for gas with lower volumes being consumed across a “normal” year as more energy demand moves to electrification. The role of gas infrastructure delivering energy to consumers will not change at the same rate or uniformly across the nation. We agree that reducing consumption of fossil fuels and increasing the proportion of “home grown” renewable energy in our supply mix will allow the nation to decarbonise, whilst also contributing to security of supply. Safeguarding our electricity system with a reliable and readily available, dispatchable energy source in the form of a gas will be critical to enabling us to meet peak demand or deliver when electric renewable sources are not available in sufficient quantities.  We fully support and welcome the recognition from DESNZ that gas infrastructure must be maintained so it is ready to manage peaks in demand throughout the transition and into the future to support clean power and security of supply. 

Renewables such as wind and solar have inherent intermittency and are exposed to periods known as ‘Dunkelflaute’. This requirement for flexibility and weather dependent lack of reliability builds in risk to security of electricity supply throughout the transition as there are not big enough batteries to store electricity for these types of periods, particularly when demand is high or the Dunkelflaute period is sustained. This is why the gas network and gases will become even more important to ensure a consistent and reliable supply of energy throughout the transition and into the future. The gas network acts as a huge energy store through the ability to line pack gas in the network ready for immediate use when it is required. The production of green hydrogen can also minimise constraint costs at the other end of the spectrum, when demand is low but renewable wind output is high. This manages the cost of the whole energy system more effectively and maximises the use of a storable energy vector in a reliable way. 

Whilst the future will likely involve greater electrification, we are pleased to see DESNZ refer to the need to maintain gas infrastructure to support dispatchable power generation. This will be a requirement during the transition and well into the future. We also see a sustained role for a gas in other areas of energy demand. For example, up to 40% of domestic properties may not be suitable for electric heat pumps^[1] and in order to prevent deindustrialisation, a gas will still be required for a wide array of industrial processes, either due to high temperature requirements of the manufacturing process or for other more practical reasons, such as limitations in electricity infrastructure or the cost of upgrading production equipment to facilitate electrification. Maintaining a safe and reliable national gas transmission and distribution network at a range of pressure tiers will be crucial to ensure that gases can reach all types of consumers when and where it is required, without interruptions. 

Liquefied Natural Gas (LNG)

The consultation explains the various sources of gas supply and the proportionate contribution they make to today’s supply mix stating that this supply mix will change: the UK continental shelf contributing less with other sources of supply such as LNG (all of which are external to the UK) playing an increasingly important role. We agree that the supply mix of gases is going to change over time. Forecasts suggest that within two years there is likely to be a global over supply of LNG, suggesting there will be a more abundant supply of gas rather than less availability which would likely lead to lower prices^[2]. This outlook puts a different context on the energy system and highlights the need to ensure the gas networks are able to accept, store and distribute LNG throughout the country as it will be a cheaper and more available energy source. Maintaining the gas network at the same time as building out electricity transmission will allow the UK energy system to respond in a more agile way to energy availability and take advantage of variations in commodity prices. Using gas storage to land LNG when it is cheaper for use at different times to when there are abundant renewables must be supported through ongoing investment in gas storage and transport infrastructure.

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[1] Recommendations for Hybrid Heating
[2] Global LNG Outlook 2024-2028}}

We agree that decarbonisation will align with improved energy security. We are confident gases will have a role in this. Decarbonisation can be delivered, and according to all of NESO’s 2025 Future Energy Scenarios^[3] can only be delivered when a gas is also available as an energy vector, therefore our gas infrastructure must be maintained to enable this throughout the transition. Gas consumption can and will be compliant with a low carbon net zero energy future in the UK through increasing production and distribution of biomethane and hydrogen as well as consuming natural gas with carbon capture use and storage (CCUS). Throughout the energy transition gas infrastructure will be critical to delivering decarbonisation in a more affordable and resilient way. Investment into all areas of the gas network must be maintained to ensure energy demand can be met safely and reliably even if demand for gas reduces over time.

2. While a reduction in gas volumes is likely to be part of the journey towards Net Zero, a significant reduction in gas infrastructure should not be assumed to be the destination at the end of the transition.

We agree that investing to maintain infrastructure to ensure there is sufficient capacity to respond to a broad range of demands when needed is key. These swings in demand are likely to be retained, if not exacerbated in a future with high renewable electrification. Therefore even once the UK is fully decarbonised, gas infrastructure will still be required to act as a back up energy supply. 

The important role of maintaining capacity is one held by both National Gas Transmission (NGT) with their National Transmission System (NTS) and the Gas Distribution Networks (GDNs) at lower pressure tiers. The NTS plays a key role in line pack and balancing the gas system as well as connecting all the import and export locations (storage, LNG, interconnectors, UKCS etc). This functionality will be necessary in a decarbonised future, so investment must be maintained to ensure ongoing good asset health.

The GDNs also play an important role in transporting and delivering supply at times of peak demand and can support with storage through line pack. The line pack in the distribution system is and will remain an important part of delivering security of supply for an intra-day demand spike during extreme weather events^[4]. They ensure supplies can get to electricity generators and industry when needed. When considering security of supply capacity in our infrastructure we must ensure the consumers who need it are connected to the supply otherwise the capacity is wasted, therefore the distribution network should not be excluded from consideration on this topic. 

Ensuring gas infrastructure resilience is a key priority as recognised in the consultation. Ensuring resilient infrastructure capacity at all pressure tiers is a key priority as the gas supply mix changes. This is because domestic, industrial and power generation sites are connected across the country at a range of pressure tiers. There are 67,000 industrial connections, 460,000 commercial properties and over 300 gas fired power stations all connected to the GB gas network, with the overwhelming majority of these connected to the gas distribution network. All levels of the gas network have to be maintained to ensure the resilience of the whole system and allow demand to be supplied when and where it is required. Given that 50% of industrial connections are outside of industrial clusters and that not all industry will be able to electrify, it is likely that in a decarbonised future a gas network will still be required to supply these businesses with energy, so maintaining investment in gas networks across all pressure tiers is necessary.

Risks to security of supply and infrastructure maintenance can also come from how the sector is perceived, and DESNZ should be mindful of this in establishing policy in this area. A narrative that the gas network will be retired over time is not borne out by what we are seeing in reality. Gas distribution networks are still connecting more new connections than they are dealing with disconnections. If this misleading narrative is allowed to persist then it will make recruitment and retention of skilled workers more difficult both as direct employees and also in the supply chain. If there is not confidence in the gas network, skills and capability will move to other industries risking the remaining gas assets. This should also be a consideration for government.

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[3] Future Energy Scenarios (FES) | National Energy System Operator
[4] Linepack flexibility}}

GB’s role in gas supply and storage to Northern Ireland

The role the GB network plays in providing gas to Northern Ireland (NI) should not be forgotten. Ensuring the people and businesses of Northern Ireland also have a secure gas supply is critical. DESNZ must recognise that forecasts from NI require gas for power generation as it is the only back up for renewables. Additionally, in NI it is not believed that gas demand has peaked, so demand forecasts in NI do not match those of GB. It may be that peak gas demand in NI does not come down until after 2030^[5].Additionally, Ireland is uniquely exposed to GB regulatory decisions, continued regulatory alignment across GB, NI and Ireland is critical. Where full regulatory alignment is not achievable, regulatory frameworks should remain compatible.

With regard to storage and infrastructure in general, there must be continued investment in line with that of GB to manage more volatile demand profiles which reflect the short term in day peaks as gas power generation is used more and more to manage renewable intermittency. This is the pattern we expect to see at Moffat due to the dominance of gas fired generation on the island of Ireland^[6]. Further to this, and noting the expected transition in GB from primarily using gas landed in Scotland to reliance on LNG shipments (and interconnector imports) which all currently land in the south of England, this will lead to a reversal in the prevailing direction of flows of gas on the GB network. FEN and our members are keen to understand if DESNZ have modelled the impacts of this change. This potential flow direction change is particularly pertinent for NI given the location of the Moffat interconnection point and our expectations of future demands as highlighted above.

Finally, whilst not in the gift of DESNZ alone, the Islandmagee storage project has the potential to be key to meeting NI’s and ROI’s future gas demand while also contributing to GB security of supply. The Islandmagee storage project is a proposed gas storage solution in Larne, Northern Ireland, comprised by underground salt caverns. We recommend that this project be featured in DESNZ's thinking around future storage options as it could alleviate dependence on LNG imports, and provide geographical diversification, for the UK as a whole.

3. Low carbon gases should not be out of scope of this consultation as a means by which to mitigate gas security of supply risk.

Security of supply is critical to ensure we have the energy we need when it is required, without interruption. The consultation refers to the need to reduce dependence on fossil fuels as a way to transition to net zero and to minimise exposure to global commodity price shocks. There is also reference to the expected significant reduction in gas consumption between now and 2050 referring to the NESO Future Energy Scenarios. Green gases can be used as a way to manage security of supply by minimising the dependance on globally traded commodities such as LNG as they are home grown and storable in our extensive gas network.

Green gases

We strongly advise the government to look at home grown sources of renewable gas to reduce the dependence on external gas supplies and help reduce the carbon emissions associated with gas consumption by further exploring the options of biomethane and green hydrogen. Electrification should be not be seen as the primary means by which to displace fossil fuel gas with renewable alternatives, but this is how the consultation currently reads.

Biomethane

In comparison to the FES25’s holistic transition, research suggests that up to 70% of GB’s methane demand in 2050 could be met by biomethane (120TWh)^[7]. We should not be excluding this gas source from the scope of government thinking on gas security of supply now as it could risk the future potential of the industry.  In the short term, biomethane is contributing to decarbonisation today, with the equivalent of 1million homes using biomethane. Biomethane’s contribution can grow and support our energy security even more as it is reliable, renewable and ready now.

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[5] Mutual energy NIGCS-2024-25
[6] Gas Capacity Statement
[7] Unlocking the Potential of Biomethane}}

While you have specifically called out electrification of home heat as a key contributor to gas security of supply (through the line on page 5 “Demand for gas is also falling thanks to our efforts to roll-out renewable power sources and electrify home heating”),  you have not recognised the value that biomethane has provided and instead ruled it out of scope. Our view is that this is a mistake, and this is borne out by looking at historical data.

Our analysis shows that biomethane has contributed more to security of supply and decarbonisation over the past 16 years than electric heat pumps by an order of magnitude of up to seven times. This is down to three key factors:

1. Assuming 11,500KWh of natural gas per home (as per Ofgem figures^[8]), the biomethane market has delivered an amount of gas which equates to significantly more homes decarbonised than the numbers of heat pumps installed.
2. The biomethane market started to develop earlier than the heat pump market in the UK, which means that the emissions benefits from the displacement of natural gas have compounded over the years since then.
3. Biomethane injection is a like-for-like displacement of fossil gas. In contrast, while we still have a power system which relies on gas as part of the mix this means installation of a heat pump does not automatically equate to an equivalent displacement of fossil gas. A heat pump installation will add to the load on the electricity system and this additional load will currently be met by gas-fired generation, given that gas is always the marginal fuel in the electricity generation merit order. This means that any fossil gas displacement from the installation of a heat pump only comes from the relative efficiency of a heat pump using electricity from gas-fired generation compared to gas being used directly in a boiler.

While this last factor will change as the power system is decarbonised and if gas is no longer always required as the marginal fuel to meet demand, it does not change the fact that biomethane has contributed more to our gas security of supply than heat electrification has to date. Our analysis below shows this clearly, comparing annual and cumulative fossil gas displacement from biomethane compared to heat pumps using electricity from gas. Even in a world where those heat pumps had been using completely renewable electricity (depicted by the dotted line in Figure 1 and lighter blue in Figure 2), biomethane has still delivered significantly more security of supply benefit.

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[8] Ofgem - average gas and electricity use}}

Key inputs to Figure 1 and Figure 2:

• Average heat pump SPF: 2.836 (Sources: ASHP ESC Electrification of Heat Demonstration Project 2025; GSHP rbandm In-situ Heat Pump Performance)
• Gas power generation efficiency: 46.6% in 2009 - 48.9% in 2024 (Source: DUKES 2025, 5.10.C – CCGT thermal efficiency)
• Gas boiler efficiency: 83% (Source: DECC - In-situ monitoring of efficiencies of condensing boilers)
• Number of installed heat pumps annually: 1,003 in 2009 - 51,199 in 2025  (Source: The MCS Data Dashboard - MCS)
• Average home gas demand (MWh/yr): 15.2 in 2010 - 11.5 in 2023 (Source: Regional and local authority gas consumption statistics - GOV.UK)

This analysis shows exactly why we should be viewing decarbonisation of our energy system and security of supply as whole systems questions which deserve whole systems answers, rather than leaning in too heavily to particular technologies or vectors. DESNZ should not be framing electricity as the only way to decarbonise and improve supply security. Biomethane clearly has a significant and important role too, so excluding it from this consultation is self-limiting. 

When it comes to future gas supply mix, if the proportion of gas supply provided to the UK by other countries increases, even if total volume of demand reduces, this still leaves the UK exposed and requires it to compete with other countries. This fact is discussed in detail in the consultation with regard to LNG and floating storage and regasification units (FRGU). We should be focusing on producing a larger proportion of the gas we consume from our own resources rather than increasing our exposure to global markets as this is the only way to ensure our supply is secured. We can use our existing infrastructure to connect and distribute biomethane and hydrogen around the UK, as well as homegrown sources of fossil-derived methane which are likely to have a far lower emissions impact than importing LNG. 

We can also make the gas we consume go further by combining it with hybrid heating solutions which reduce demand by up to 75%^[9]. We can make up to 120 TWh of biomethane sustainably by 2050^[10] and can safely distribute hydrogen (100% or blends) in all pressure tiers of gas^[11]. Using gases we generate ourselves whilst distributing them with our world class network can help contribute to the net zero transition and reduce the demand on the electricity network at times of peak demand thus reducing emissions and costs. It gives us flexibility and control as these gases are storable, flexible, dispatchable, renewable, home grown, at the same time securing jobs in our country.

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[9] Unlocking the power of Heat Pumps with hybrid installations
[10] Unlocking the Potential of Biomethane
[11] LTS Futures}}

Green hydrogen

Hydrogen has also been deemed as out of scope in this consultation. Hydrogen is another potential source of home grown renewable gas which could help manage exposure to global commodity cost fluctuations, make use of surplus renewable energy and support security of supply. While we recongise this consultation is primarily aimed at a nearer term security of supply concern, and hydrogen will likely take time to develop as an important vector in our energy system, that doesn’t mean that green hydrogen should be ruled out of scope as a means by which to contribute to gas security of supply in the long term.

The 2025 NESO Future Energy Scenarios all highlight a significant requirement for hydrogen in order to deliver net zero. We understand the forthcoming Hydrogen Strategy will likely refine and minimise the use cases of hydrogen. This decision would risk the viability of the hydrogen economy due to it limiting the demand of hydrogen therefore restricting the opportunities for the cost of hydrogen production to be managed and reduced. If government fail to create an investable environment for the production of hydrogen now this risks the failing to deliver the required volumes of hydrogen we will need it to in the future. This is a significant risk not only to security of supply but also jobs and growth in the UK.

The consultation frames moving from gas to electricity to be the right choice to ensure security of supply. For this to be accepted as valid, government and all involved would need to understand the total cost and complexity of the counterfactual: making the electricity system ready for this new demand. We urge government to publish evidence you have on this to allow assurance and validation of this data. It may prove cheaper and less complex to invest in low carbon gases alongside electrification, so that both low carbon energy vectors can contribute to mitigating security of supply concerns.

Regulatory Changes

We are supportive of a review of the Wobbe index and encourage it to be as holistic as possible including ensuring any potential changes undergo cross-border impact assessments and engagement with relevant bodies to ensure continued compatibility with connected jurisdictions. Both the upper and lower ends of the range need to be considered to ensure we can reduce emissions from both from LNG ballasting and biomethane propanation. It makes little sense to increase the emissions associated with gas usage by adding nitrogen or propane to various sources of methane. Instead, a broader review of gas settlement and billing arrangements to ensure consumers get charged for the gas they consume is needed. This broader review will also pave the way for increased hydrogen blending above 5% in the distribution network.  With these and other regulatory changes, FEN and its members want to work with Ofgem, HSE and DESNZ to ensure regulation is fit for purpose and supports decarbonization of gases as well as ensures the safety and security of supply of the network.