The Climate Change Committee published a report on 9 March 2023 concluding that a reliable, secure and decarbonised power system by 2035 is achievable, but not at present rates of delivery. The committee, which advises the UK government on carbon budgets and net zero targets, said the report demonstrates the scale of the task in meeting the government's 2035 goal and contains 25 new recommendations to improve the prospects of delivery1.
The committee's modelling sets out the shape of a 2035 system. Across the year, renewables and other relatively inflexible generation, meaning nuclear and bioenergy with carbon capture and storage, contribute around 70% and 20% of generation respectively, with the remaining 10% covered by low-carbon flexible options1. The committee factored in a 50% increase in electricity demand to reflect expected growth in electricity use in transport, industry and buildings1. It also tested a scenario of an extended 30-day period of wind drought, built by combining the 30-day period of highest residual demand with the 30-day period of lowest wind load factors over 2009 to 2019. The committee said this is designed to test a more extreme scenario and does not have a historical precedent1.
The report states that delivery and deployment of infrastructure must be achieved at a much greater pace than present regulatory, planning and consenting regimes can achieve, requiring that barriers to swift deployment are removed and policy gaps remedied1. It identifies three needs alongside government commitments on renewables and nuclear: new low-carbon back-up generation, including hydrogen-based power stations and some continued use of fossil gas made low-carbon through carbon capture and storage; smart shifting of consumer demand, especially through controlled timing of electric vehicle charging and use of heat pumps; and new storage beyond batteries, most critically using surplus generation to produce hydrogen through electrolysis1.
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."
The committee reports that emissions from electricity generation have fallen 69% since 2010, and that renewables continue to be the cheapest form of electricity generation1. 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.
Why it matters for households
The report's central claim is that a decarbonised grid would cut exposure to volatile international fossil fuel markets by relying more on homegrown renewables, and that this carries new significance after the recent period of heightened energy insecurity1. For a household, the practical consequences sit in the demand side the committee describes: controlled timing of electric vehicle charging and heat pump use, so that peaks are smoothed and excess supply absorbed1. That points to a system in which when a car charges or a heat pump runs may matter to the wider grid, not only to the bill. The committee also notes that managing the variability of renewables imposes some extra costs on the wider system, which it describes as manageable given that low-carbon flexibility options make up a relatively small proportion of generation and capacity1. The report does not set out household costs or bill effects, and no such figures have been reported1.
What happens next
The report makes 25 recommendations, including that the government must commit to a long-term cross-sectoral infrastructure strategy covering hydrogen and electricity infrastructure, identifying low-regrets investments that can proceed immediately1. No timetable for government response is given in the report1.