The role of gas in generating electricity
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This is the second in a series of briefings from Energy UK and the Carbon Capture and Storage Association (CCSA), exploring the role of gas in the transition to a Net Zero economy.
This briefing specifically focusses on the role of gas in generating electricity. The first briefing in the series looked at the broad role of gas across the whole economy. Visit the Fuelling the Future webpage to read further briefings.
It is clear that we need to decarbonise our electricity supply and to do so we need to replace unabated gas (where the emissions aren’t captured and stored) with low-carbon alternatives over the coming decades. This will mostly happen by ramping up renewables, especially wind and solar.
Gas currently plays an important role in electricity generation and is the largest single source of electricity generation. It’s currently used for flexibility and resilience, so it is important to manage the inevitable reduction of gas for generation carefully.
To meet energy demand in the UK, the Government has proposed that the UK will need a limited amount of unabated gas into the 2030s, and possibly beyond, due to delays in developing low-carbon infrastructure, such as carbon capture, utilisation and storage (CCUS). Therefore, we need to consider a wider range of technologies to replace unabated gas to replicate its roles, which includes using flexible demand, electricity storage and interconnectors with Europe. It is paramount for the UK to ensure that these technologies are deployed as quickly and effectively as possible.
Gas with carbon capture and storage (CCS) and hydrogen-to-power (H2P) are also likely to play a unique role because of the importance of having low-carbon and dispatchable sources of electricity that use a fuel. CCS and H2P offer a way of delivering the benefits that gas currently provides to the electricity system, but with reduced emissions (termed “abated” gas). This is in addition to storage technologies like batteries.
The Government needs to provide clarity on the targets for decarbonising the electricity system, as well as going further and faster in creating new markets and continuing to develop business models for alternatives to unabated gas.
Why is gas important for electricity?
Although renewable energy is increasingly becoming a significant portion of our electricity mix, gas usually generates around a third of the total electricity for the UK, more than any other single source. Broadly, there are two different roles played by gas:
- Providing bulk electricity: some gas turbines can make electricity very efficiently, meaning we presently use them to provide a large proportion of the electricity we need for long periods.
- Keeping the lights on: gas is dispatchable and can be turned on at short notice. This makes it useful in providing electricity for periods when there may be lower than expected supply from other sources.
Although useful to maintain a stable electricity supply, burning gas creates carbon emissions. To avoid those emissions and take advantage of alternative technologies (especially renewables and storage) that are getting cheaper and more efficient over time, the role of gas will change. By 2030, if not before, most electricity will be generated by renewables.
How we use gas has changed
Since 2000, the amount of electricity from gas has remained relatively stable, varying between just over a third and just under a half of total generation. However, the role that gas plays in providing electricity changed significantly during that period and it will continue to change dramatically in the coming years.
The renewable energy revolution
In the early 2000s, gas and coal provided most of our electricity, with gas plants running almost constantly and occasionally ramping up to meet peaks in demand. As seen in Figure 1, there has been a shift in the past 15 years in which coal generation has been removed almost entirely from the grid, balanced by a colossal increase in renewables.
Figure 1: Electricity generation by source (2000-2023)

Source: DESNZ energy trends
The displacement of coal with renewables has allowed the UK’s electricity sector to reduce its emissions by two-thirds in just over a decade.[1] It has also meant gas has taken on a different function.
[1] DESNZ (2024): Provisional UK greenhouse gas emissions national statistics 2023
Currently, there are significant periods when wind and solar (alongside nuclear, biomass and stored and imported electricity) can provide almost all of the electricity we need, resulting in some gas power plants to be idle for part of the time. Recent record low-carbon intensities of electricity generation exemplify this, as shown in Figure 2. For example, at 1pm on 15th April 2024, only 2.5% of electricity came from fossil fuels. By comparison, in 2010 the lowest share was 57% and in 2018 it had never dipped below 10% [2] , [3]
Figure 2: Share of renewable versus fossil fuel generated course of electricity 2010 – 2024

Source: ESO (2024): Historic generation mix and carbon intensity
[2] ESO (2024): Historic generation mix and carbon intensity
[3] DESNZ (2023): Digest of UK Energy Statistics 2023
Conditions change though and when there isn’t enough electricity generated by the wind and sun, gas plants come online to make up the difference. This means the amount of electricity that is generated from gas is increasingly variable, but necessary to ensure that demand is met at all times.
Moving towards a decarbonised power sector
A vital stepping stone to the UK reaching Net Zero carbon emissions by 2050 is the official Government target for our electricity generation to be decarbonised by 2035.[4] This will be achieved by replacing unabated gas with other sources of electricity, mostly by building more renewable and nuclear capacity.
[4] HM Government (2022): British energy security strategy
The UK has ambitious targets of 50GW of offshore wind by 2030, 70GW of solar by 2035 and 24GW of nuclear by 2050.[5] This will enable the amount of electricity generated to increase by up to three times between now and 2050, which we will need to meet the increased demand for electricity from heat pumps and electric vehicles (EVs), for example.[6]
[5] HM Government (2022): British energy security strategy
[6] Energy UK analysis of ESO (2023): Future Energy Scenarios 2023
Even with a faster rollout of renewables, it has been proposed by the Government that unabated gas will continue to play a role in back-up capacity to plug the near-term supply gap arising from delays in low-carbon infrastructure and generation.
As Figure 3 shows, the capacity of unabated gas power stations will be around the current level for the next decade before gradually falling away. The amount of electricity generated from gas (and therefore carbon emissions), however, will decline rapidly in the coming years as it is displaced by renewables.
Figure 3: Unabated gas capacity and generation in a range of Net Zero scenarios

Source: Electricity System Operator (2023), Future Energy Scenarios
The amount of electricity generated from gas (and therefore carbon emissions), however, will decline rapidly in the coming years as it is displaced by renewables.
The rest of this briefing explains why in the medium term it is not possible to keep the lights on through the next phase of the energy transition in the UK without relying on unabated gas for at least some of the time. At the same time, the UK must make sure the technologies that will take over from unabated gas are deployed as quickly and effectively as possible.
The challenge of keeping the lights on
Ensuring that electricity is available at the flick of a switch is a unique challenge. Unlike any other product we consume, the supply of electricity must match the demand for electricity in real time, 24 hours a day. That becomes harder with more renewable generation on the grid, although advances in technology and markets make it possible to run a more flexible, renewables-led energy system.
Figures 4 and 5 show how gas currently steps in to make electricity when renewables are not providing enough. Despite fluctuations depending on the weather, weekends and holidays, daily demand is relatively stable as is the electricity provided by nuclear and biomass power stations. Wind, however, while being largely predictable does change frequently with gas generation making up the shortfall, and little gas generation when there is a lot of wind. The latter will occur more frequently as more wind capacity comes online.
Figure 4: Daily electricity generation in Q4 2023

Source: Energy UK analysis of Elexon Balancing Mechanism Reporting Service
Note: Great Britain excludes embedded generation (e.g. solar)
This can be seen in Figure 5 which compares two half-hour periods a week apart in winter 2023. On a still morning on Saturday 2nd December 2023, 70% of electricity was provided by gas, whereas on a blustery morning a week later on the 9th almost half of electricity came from wind, with gas providing only 7%.
Figure 5: GB electricity demand by generation source on a high-gas and low-gas day

Source: Energy UK analysis of Elexon Balancing mechanism reporting service
Note: Great Britain excludes embedded generation (e.g. solar)
Balancing the grid
Gas, for now, also plays a role in how the grid is fine-tuned in real-time. To ensure a steady supply of electricity, the National Grid has to balance supply and demand throughout the day. To do this the control room asks power stations (as well as batteries, large users of electricity and cables to Europe) to make or use more or less electricity on a second-by-second and minute-by-minute basis in a market called the Balancing Mechanism.[7]
[7] See the Energy System Operator’s guide to the Balancing Mechanism here
This ensures that if millions of people put the kettle on at the same time or a power station has a problem and needs to quickly shut down, there is still a constant flow of electricity. The flexibility of gas means that it is currently used for a significant proportion of the actions taken by the control room.
Figure 6 shows gas and other fuels used to provide additional power in recent years, with gas consistently representing the majority of “buy” actions where the control room needs additional electricity at short notice. This will begin to change, however, with the rollout of further ways to store low-carbon electricity for extended periods.
Figure 6: Fuels used to provide additional power at short notice in the Balancing Mechanism

Source: Energy UK analysis of Elexon Balancing Mechanism Reporting Service
Note: excludes embedded generation (e.g. solar)
The alternatives to unabated gas
There is no single solution that will allow us to entirely remove unabated gas from the electricity grid. Instead, a combination of technologies will need to be used, alongside innovations in the market for electricity. It will take time to deliver this, but bold decisions and ambition from Government can see us move away from unabated gas more quickly.
Flexibility
Market mechanisms can help electricity usage patterns better match the electricity being generated from renewables:
- Flexible tariffs: prices that are cheaper when there is a lot of electricity from renewables will encourage households and businesses to shift their usage away from times when we currently need to use gas.
- Demand-side response: when there isn’t enough electricity, we normally turn up a gas power station. But it is also possible to financially reward homes and businesses to turn down the amount of electricity they are using. Expanding that market will allow us to use less gas. Energy UK has produced a further briefing on this area.
More grid infrastructure
Being able to move more electricity within Great Britain and internationally will allow us to maximise the use of renewables:
- Transmission capacity: a lot of renewable generation is in places like Scotland and the North Sea, a long way from demand centres like London and the south east of England. Sometimes, there is more electricity generated in the north of Britain than the grid can carry, meaning turning off wind farms in Scotland whilst burning gas in England. Record investment in the grid will help solve that issue.
- Interconnectors: trading electricity with our European neighbours will allow us to use their electricity when they have surplus and vice versa, allowing for increasingly clean electricity on both sides of the Channel as we optimise generation at a continent-wide level.
Energy storage
We will need to be able to store excess electricity for use at later times, both over a couple of hours (like saving spare, midday solar power for the evening) and between seasons (like storing electricity in preparation for a cold winter). A range of technologies can do this, such as:
- Batteries: either large scale or using the batteries in electric vehicles (EVs).
- Pumped hydro: pumping water uphill ready to release and generate electricity later.
- Thermal storage: turning electricity into heat which is held to be used later.
- Flywheels: spinning large wheels which will hold energy in the short term, helping make the grid more stable.
There are many more storage technologies early in their development which might play an important role but require more support to research and scale. These include novel batteries, compressed air and gravity systems.
A cost-effective transition
- Gas prices can be volatile: paying for gas to make electricity costs money. International gas prices can be volatile, as seen in the 2022 crisis. The UK imports a significant proportion of its gas (46% in 2022), making us dependent on other countries and impacting our balance of trade.
- Renewables save money in the long run: renewables require upfront investment but then deliver very cheap electricity for many decades. Investing in supply chains, research and development will reduce the upfront costs of renewables even further, as will continuing to use tools that derisk investment and lower financing costs like the Contracts for Difference programme.
- System-level costs matter: there are lots of different ways to develop the electricity system as it decarbonises. Market mechanisms should be established and used to find the optimum mix of technologies to build and the most efficient way of using them. It is likely that the most cost-effective system will use some small amount of unabated gas to provide dispatchable capacity. Any technology (be it unabated gas, hydrogen or gas with CCS) that needs to be built and maintained but only used in certain circumstances will appear expensive per unit of electricity it produces. However, those costs allow the use of cheap renewables for the rest of the electricity we use.
- Low-carbon fuelled generation will become more economical: as hydrogen and CCS technology develop over time, costs will fall. Simultaneously, carbon prices in the UK are designed to increase as decarbonisation progresses. This means that hydrogen and CCS will become gradually more cost-competitive, making the role of support mechanisms less significant as the sector matures.
Decarbonisation pathways for unabated gas
Burning a gas (whether that is natural gas or hydrogen) to spin a turbine will remain a key tool in making electricity. This is because natural gas is a traded commodity that can be stored until needed, independently from the electricity grid, making it indispensable for extreme situations like a very cold winter or an extended period with below-average winds. Whilst the industry is still in its early stages of development, the same will likely be true of hydrogen. Therefore, we need to find ways of burning natural gas and hydrogen without emitting carbon. This can be done in two ways.
Hydrogen
Most hydrogen is currently made from natural gas in a process that emits carbon. In the future, however, more hydrogen will be made either from fossil fuels and capturing and storing the emissions from its manufacture (blue hydrogen) or through electrolysis (green hydrogen), which needs only water and clean electricity. To enable these to be price competitive with natural gas, there will need to be subsidies to drive decarbonised solutions.
Pure hydrogen, as well as hydrogen blended with natural gas can be burned in gas generating plants which are similar to the standard gas-powered plants that we have today. Some significant modifications to the plant will be needed for higher hydrogen blends, whilst plants running on pure hydrogen are under development.
Power CCS
Fitting natural gas generation with CCS, where the carbon from the power station’s exhaust is captured and stored safely underground, is a key pathway for conventional plants to continue using gas without adding more carbon to the atmosphere.
How much will we need to build?
It is hard to tell exactly what our energy system will look like in future, but some estimates include:
- The Government: according to a recent consultation, we will need at least 30GW but potentially up to 50GW of long duration energy storage (including some unabated gas, gas with CCS and hydrogen) by 2035. Separately, the Government has estimated the need for 10GW of power CCS by 2035.
- The Climate Change Committee: for a decarbonised power system in 2035 we will need 17GW of dispatchable low-carbon capacity in addition to 12GW of unabated gas (although this will only provide 2% of electricity).
- Electricity System Operator: in its Future Energy Scenarios, pathways that reach Net Zero in 2050 see 9GW-12GW of hydrogen and CCS capacity and up to 23GW of unabated gas.
What needs to happen?
It will take a concerted effort and decades of development to move from where we are today to an electricity system that uses no or very little unabated gas. The following actions from Government will be crucial to delivering our ambitions:
- Clarity of vision: the Government must make it clear what the decarbonisation targets are for the electricity system, including a definition of what “decarbonisation” means by 2035 and what exemptions will be made for security of supply.
- Facilitate the shift to hydrogen and CCS: for hydrogen and CCS to work at scale, there needs to be more clarity on future funding levels and business models, especially for the production, storage and transportation of hydrogen, as well as the delivery of hydrogen to power generating plant. Meanwhile, the Dispatchable Power Agreement (DPA) business model for power CCS is well advanced, and is expected to evolve as carbon clusters and infrastructure develop and contractual negotiations that are currently underway enable learnings for future projects. A greater understanding of how existing plant can be retrofitted with CCS or to be able to burn hydrogen within the existing market frameworks will also be crucial for the shift to hydrogen and CCS.
- Expand variable renewables: the heavy lifting for reducing and ultimately removing unabated gas from the system will be the mass deployment of renewables, especially wind and solar. This must accelerate in line with Government targets, mostly using existing market mechanisms like Contracts for Difference, that must be fit for purpose and reflect current market conditions.
- Optimise the use of existing business models: there are already well-developed mechanisms for encouraging the right capacity to be built and operated so that we have a constant supply of electricity. These should continue to be used to support the shift away from unabated gas:
- Balancing Mechanism: reforms to allow for better use of low-carbon options (like batteries and demand side response) in operating the grid over gas should continue.
- Capacity Market: the Capacity Market will remain the primary mechanism for ensuring enough flexible capacity is built and kept running to keep the lights on. It must evolve to do so in a way that delivers a mix of technologies, potentially including unabated gas that can transition to running with hydrogen/CCS.
- Create business models for long duration energy storage: most long-term storage technologies cannot compete in the current market. Existing and new mechanisms must be used to allow the development of these technologies, starting with explicit subsidies for emerging technologies before transitioning to all technologies competing on a level footing.
- Prepare a skilled workforce: a successful shift from unabated gas will require a strategic effort to address crucial skills gaps. The Government needs to publish an action plan on how we can prepare a workforce that can deploy and operate the wide range of projects that will deliver this transition.