The Climate Change Committee published a report on 9 March 2023 setting out what a reliable, secure and decarbonised power system in 2035 could look like, and concluding that it is possible but "will not happen at current rates of deployment"1. The report carries 25 new recommendations to improve the prospects of delivery1.
The modelling is built on an hourly representation of demand and generation, using historical annual weather patterns to simulate future years1. Across the year, renewables and other relatively inflexible generation (nuclear and bioenergy with carbon capture and storage) contribute around 70% and 20% respectively of generation needed, with the remaining 10% covered by low-carbon flexible options1. The CCC has factored in a 50% increase in demand on electricity, to reflect expected increases in electricity use in transport, industry and buildings1. Emissions from electricity generation have fallen 69% since 20101.
The CCC also tested a scenario of an extended 30-day period of wind drought, combining the 30-day period of highest residual demand with the 30-day period of lowest wind load factors over 2009 to 20191. It states this is designed to test a more extreme scenario and does not have a historical precedent1.
Alongside the Government's Energy Security Strategy commitments to renewables and nuclear, the report identifies three further requirements1:
| Requirement | Detail given |
|---|---|
| New low-carbon back-up generation | Hydrogen-based power stations and some continued use of fossil gas, made low-carbon through carbon capture and storage |
| Smart shifting of consumer demand | Smoothing peaks in demand and absorbing excess supply, especially through controlled timing of electric vehicle charging and use of heat pumps |
| New storage solutions | Beyond batteries; most critical is using surplus generation to produce hydrogen through electrolysis, providing long-term storage for later electricity generation |
Lord Deben, Chairman of the Climate Change Committee, said:
"We know how to do this, but Government is asleep at the wheel. Recent commitments for new nuclear and renewables are welcome, but these alone are insufficient. A rapid overhaul of the planning system and regulations is needed. It is not clear where the responsibility lies for the design and operations of our modern energy system rests among key organisations."
Baroness Brown, Chair of the Adaptation Committee, said climate risks to the electricity system are currently underplayed and that resilience needs to be built in now as the system is scaled1. The CCC recommends that the Government must commit to a long-term cross-sectoral infrastructure strategy, identifying low-regrets hydrogen and electricity infrastructure development and areas unlikely to be suitable for hydrogen1. It also states that renewables continue to be the cheapest form of electricity generation1.
Why it matters for households
The report's central claim is that a system relying mainly on UK renewable resources would cut exposure to volatile international fossil fuel markets1. For a household, that connects to how electricity is generated and priced over time, and to the CCC's expectation that electricity use rises by 50% as transport, industry and buildings switch away from fossil fuels1. Two of the three additional requirements touch the home directly: controlled timing of electric vehicle charging and use of heat pumps, and the storage and back-up generation needed when wind output is low for extended periods1. The CCC's stress test of a 30-day wind drought, without historical precedent, is the part of the analysis that speaks to reliability rather than only to emissions1. The report does not set out household costs, bill impacts or support schemes; those are not reported here.
What happens next
The report sets no dated milestones of its own. It states that delivery and deployment must happen at a much greater pace than present regulatory, planning and consenting regimes can achieve, that barriers to swift deployment of critical infrastructure must be removed and policy gaps remedied, and that network and storage build is required for electricity, hydrogen and CO21. The CCC's recommendations are addressed to Government; no Government response date is given in the report1. The UK's progress against its carbon budgets and net zero targets is tracked separately, and wider regulation and policy changes would be needed to move the 2035 goal forward1.