What are marine renewables?
The term ‘marine renewables’ is commonly used to refer to technologies that harness energy from the sea to generate electricity. This could be from waves, tidal streams and tidal ranges, for example. It is sometimes used more broadly to include any renewable technology that operates at sea, including offshore wind, although the focus of this debate will be wave and tidal energy.
Marine renewables in the UK
There are currently around 10 megawatts (MW) of wave and tidal energy capacity in the UK. This has increased little since 2020 and peaked at 22 megawatts in 2019. Its contribution to UK generation is currently less than 0.01%.
Government data shows that 7 tidal stream projects have received planning permission with a total installed capacity of 355 MW. A further 5 tidal stream projects and two shoreline wave projects have planning applications submitted, with a total proposed installed capacity of 336 MW. By comparison, around 23,000 MW of offshore wind generation is under construction or awaiting construction.
Government policy on marine renewables
Neither the previous government nor the current government have set any targets for the installation of either wave or tidal energy.
The government has set a target to achieve at least 95% of low carbon generation by 2030. Its December 2024 Clean Power 2030 Action Plan does not set any specific targets for marine renewables but does see them potentially being deployed at scale and playing a role in the UK’s longer-term decarbonisation objectives.
The government’s primary way of supporting new low carbon power infrastructure is the contract for difference (CfD) scheme.
CfDs work by guaranteeing a set price for electricity (known as a strike price) that generators receive per unit of power output. As the wholesale price of electricity fluctuates, the generator is either paid a subsidy, or pays back, so that they always receive the value of the strike price. The cost, or benefit, is passed on to consumer bills.
The government changed the way that offshore wind and tidal stream technologies compete for funding in the fourth allocation round of the CfD scheme, held over 2021-2022. This led to tidal stream being awarded CfDs for the first time at that allocation round and in the two subsequent rounds in 2023 and 2024. No wave energy projects have been awarded CfD contracts to date.
Further reading
The following briefings from the Commons Library and the Parliamentary Office of Science and Technology (POST) provide background on these technologies: