Hydropower has served the UK incredibly well for over a century as a renewable electricity resource, helping to decarbonise the country’s power system. It has cumulatively saved the need to generate 300TWh from other sources, leading to an estimated saving of 160 million tonnes of CO2 equivalent emissions over that same period. However, the sector has yet to fully develop to the levels that have been previously suggested.

According to the UK Hydropower Resource Assessment 2022, a new report produced by The Energy Informatics Group at the University of Birmingham and commissioned by the British Hydropower Association, UK hydro is “an engaged sector that wishes to develop more”. It believes it has an increasingly important role to play in the security of supply as part of an overall net-zero generation portfolio. Furthermore, the sector has shown it is able to continue to innovate through the co-location of hydropower schemes with battery storage and the development of pico-scale hydropower systems.

The report’s aim was to provide an evidenced assessment of the potential of additional hydropower generation that could support the UK’s target of net zero. It suggests that “a sound representative estimate” of 217.5MW of hydropower could be built by 2030 under a favourable policy environment, which if scaled up across the whole UK would be up to 1.4 GW. However, a more conservative value is considered to be 1GW of additional capacity that would generate an estimated 1.5 % of the UK’s net-zero annual electrical demand by 2050.

According to the report, the main barriers to further hydropower deployment in the present climate include a lack of ongoing financial certainty, as well as difficulty in obtaining environmental licences, grid connections and planning permission. These challenges can be addressed, and the sector reinvigorated by implementing the report’s following five recommendations:

  1. The UK should target a 50% increase in its hydropower capacity.
  2. The Department for Business Energy and Industrial Strategy should continue to engage with the British Hydropower Association on the relative merits of different funding mechanisms to incentivise 1GW of additional deployment. The survey of BHA members which formed part of the report supports the level of certainty provided through a bankable policy such as a Contract for Difference as a more favourable approach than an upfront grant. However, upfront grants could be more favourable for small schemes, to help offset some of the initial costs such as consenting and electrical grid connections.
  3. Consideration should be given to a more coordinated approach to hydropower projects for planning and consenting and a greater sharing of best practices between the devolved environment agencies. There should be more proportionate levels of consenting fees which do not disproportionally reduce investment in the sector at the smaller scale of development. Plus more proportionate levels of valuation office business rates which do not disproportionally reduce investment at certain capacity levels, and a greater sharing of best practices between the different valuation offices across the UK.
  4. There should be a single publicly available dataset for all hydropower installations in the UK that defines a unique reference number for each installation. It would be useful if this publicly available dataset had at a minimum: the capacity of the installation, the location of the installation and the date of commissioning. This would help to manage the problem of slightly (or even very different) hydropower site names that exist between different public bodies
  5. A new detailed resource and techno-economic hydropower assessment should be commissioned and coordinated by the Department for Business, Energy and Industrial Strategy with input from relevant bodies from the Scottish Government, Welsh Parliament and Northern Ireland Assembly. This would make use of up-to-date LIDAR data, weather data (with consideration of climate change impacts) and other assumptions to reflect advances in hydropower system designs, the wider electrical generation portfolio, electrical network connections and the challenges of reaching net zero. The study could also consider low-head and pico-micro-sized installations

In conclusion, the report states that the evidence it has presented shows that hydropower should be viewed as an increasingly useful element of the UK’s diversified electrical generation portfolio.

“Hydropower is a proven and reliable technology,” says Kate Gilmartin, CEO of the British Hydropower Association. “The UK has an established hydropower supply chain, so nearly all of the support needed to unlock this investment will stay in the UK economy, creating jobs and growth.”

Tidal technologies

The BHA has also welcomed parliamentary committee calls for the UK to generate a significant proportion of its power from tidal and marine energy.

A new report, released by the Environmental Audit Committee (EAC) in January 2023 after a nine-month inquiry, considered the transitional role of oil and gas in the UK’s energy mix and scrutinised the Government’s British Energy Security Strategy.

The report highlights that tidal technologies get ‘scant attention’ in the strategy, despite the tidal range having the significant benefit of predictable and reliable, year-round, energy generation. It said that tidal energy projects should be “a vital component” of the government’s strategies and that the UK should be aiming to generate a significant proportion of its power from these sources by the middle of the 2030s.

The government had previously withdrawn support for tidal range, stating that costs are higher than alternative sources of low-carbon power. However, a recent review undertaken by the University of Birmingham found that the tidal range is cost-competitive with other low-carbon energy projects.

The BHA recommends that the government extends the support currently being received by the newly formed body called Great British Nuclear, which is receiving a £120 million development fund for new projects. It should match this with the Great British Tidal Rang’ and an equal development fund to bring forward the 13GW of tidal range projects currently proposed. This should sit alongside a development road map to ensure the more urgent speed and scale of delivery that the EAC report recommends.

The report states the need for grid reliability that embraces smart opportunities and requires deeper flexibility. BHA calls for pumped storage and hydropower to be considered, as the only renewable energy sources able to deliver the grid reliability highlighted in the report. An expansion in both will be needed to provide grid stability to match the growth of intermittent renewables.

The BHA welcomes the call for the government to provide a progress report in 2023 that should include the related plans to enable large-scale, long-duration electricity storage. All of which will be crucial to realising a secure, stable, low-carbon grid.

This article first appeared in International Water Power magazine.