The Anonymous Widower

UK Pumped Storage Projects Surge After 40-year Gap

The title of this post, is the same as that of this article on International Dam and Waterpower Construction.

This is the sub-heading.

Plans are underway to ensure the UK soon adds to its pumped storage portfolio, which hasn’t seen the development of a new project for over 40 years

This first paragraph gives a summary of the new pumped storage hydro schemes under development.

According to the British Hydropower Association (BHA), although the UK hasn’t witnessed new pumped storage capacity for over 40 years, there are now 11 schemes at various stages of development across Scotland and Wales, with a combined 10 GW and 200 GWh of storage capacity.

Note.

1. Currently, there is a total of 2.8 GW/24-26 GWh of pumped storage hydro in the UK in four plants.
2. Two are in Scotland and two are in Wales.

The world’s largest operational pumped storage hydro scheme is the Fengning Pumped Storage Power Station in China, which is 3.6 GW/ 40 GWh.

The second paragraph gives details of Coire Glas, which is one of the largest being constructed.

Mike Seaton from SSE Renewables gave an update on a project his company has been working on – the 1.4GW and 30GWh, £2 billion Coire Glas scheme. Planning consent was given in 2020 and a 1km exploratory tunnel has already been dug. With the final investment decision expected in 2026, the scheme could be generating power by 2033.

Note.

1. This scheme is almost half the size of the world’s largest scheme in China.
2. It is planned to take thirteen years to build from planning permission.
3. The slightly smaller 1.7 GW/9.1 GWh Dinorwig power station took ten years to build and cost half a billion.

Pumped storage hydro powerstations consume a lot of time and money in the building phase.

The View Of An MSP Is Given

Michael Matheson MSP said this.

Working alongside the British Hydropower Association, it is my ambition that frank and open engagement can take place between industry, developers, and communities to ensure that Scotland maximises it’s PSH potential while delivering real improvements for communities and driving towards a sustainable economy and energy mix.

That’s a good attitude.

Scottish Pumped Storage Experience

Under this sub-heading three new large schemes are outlined.

• Earba – 1.8 GW/40 GWh
• Fearna – 1.8 GW/36 GWh
• Glen Earrach Energy – 2 GW/34-46 GWh

Note.

1. All seem to have at least initial planning permission.
2. All are larger than Dinorwig.
3. The three schemes total around 5.6 GW/ 116 GWh.

Scotland seems to be finding places to site these monster pumped storage hydro systems.

Cap & Floor For Pumped Storage Hydro

This paragraph talks about how the authorities and an energy company are talking about a better financial regime, that will encourage investment.

Gilkes Energy is also working with the UK Government and Ofgem to implement the Long Duration Energy Storage (LDES) ‘Cap & Floor’ mechanism in 2025. This policy is expected to facilitate investment in PSH projects by addressing financial risks. Crompton noted that the mechanism has already attracted private investment for interconnectors and is expected to do the same for pumped storage.

Note.

1. My experience with truck leasing and peer-to-peer lending, tells me, that if you want billions you can get it.
2. Goldman Sachs has taken an interest in Highview Power, who are developing liquid-air batteries, which are up to 300 MW/ 3.2 GWh.
3. Barclays have also invested in specialist batteries to charge electric buses, as I wrote in First Bus To Launch 1MW BESS Unit In Hampshire, Aberdeen To Follow.
4. From what is said in World’s Largest Wind Farm Attracts Huge Backing From Insurance Giant, I can see big insurance companies like Aviva, helping to fund pumped storage hydro.

With pumped storage hydro, which is very much a scenic asset, the CEO of the investing company can have a nice picture on his wall.

Upgrading Sloy

The upgrading of Sloy hydro power station to a pumped storage hydro powerstation, is unusual, but the sort of practical idea, that engineers think up over a few pints of real ale.

These two paragraphs outline the Upgrade.

Back in April, SSE Renewables submitted a Section 36 planning application to the Scottish Government to convert the existing Sloy Power Station near Loch Lomond into a pumped storage hydro scheme. The proposal would see the station, which has operated since 1950, adapted to include a pumping capacity of up to 100MW, allowing it to deliver up to 16GWh of long-duration electricity storage. If approved, SSE plans to reach a final investment decision by late 2027, with the conversion completed and operational by the end of 2030.

The project would involve installing new pumps at the Inveruglas site, enabling water to be pumped from Loch Lomond to Loch Sloy during low electricity demand periods. This stored water would then be released to generate electricity when demand is higher. The application also includes a proposal to upgrade the station’s existing 32.5MW G4 turbine, which would raise the plant’s total generating capacity from 152.5MW to 160MW.

 

Note.

1. Sloy has been operating for 76 years.
   It looks like it could be a 160 MW/ 16 GWh pumped storage hydro powerstation.
   I doubt there would be any planning problems.

With Cruachan pumped storage hydro powerstation and the 300 MW/3.2 GWh Highview Power battery at Hunterston, it would be one of a number of assets protecting Glasgow’s electricity supply.

New Ways To Use Water

This section starts with these two paragraphs.

As discussions at a recent webinar hosted by the International Hydropower Association highlighted, other technologies need to be able to step up to provide deep storage in locations where conventional pumped storage is unable to.

Gavin O’Leary is the Head of Electricity Storage Policy at the Department for Energy Security and Net Zero (DESNZ). Explaining that although the UK has 2.8GW of Long Duration Energy Storage (LDES) capacity installed in the form traditional pumped storage across four sites, he said: “We have not found the right model in a privatised electricity grid to incentivise development of storage.” And that’s why the country has gone over four decades without adding to its stockpile of long duration storage.

O’Leary also says, that it takes a long time to build.

Scalable Solution

This section starts with these two paragraphs.

Stephen Crosher is the CEO of RheEnergise, a company that is developing High-Density Hydro. Based on traditional pumped hydro storage, it claims to be solving the challenges the technology faces, such as lack of sites, environmental and social issues around flooding valleys, water abstraction, the time taken to consent and construct, plus distances from generation or demand.

RheEnergise’s solution is a form of gravitational energy storage that pumps proprietary fluid uphill. And with the LDES market predicted to be US$4 billion by 2040, with rapid scaling and exponential growth, Crosher says there is a “huge demand for solutions to solve the problems”.

High Density Hydro, the company believes, is a scalable pumped storage solution for the future.

As I thought so too, I invested a small amount of my pension.

Although RheEnergise looks good, there is one small drawback.

Although they’re “looking for small hills and not mountains” for prospective project sites, Crosher admits that elevation can be a prohibiting factor. Consequently in the UK, flatter areas such as East Anglia, along with other countries such as The Netherlands, won’t provide favourable conditions. However a small hill or mine or mine shaft will suffice. In fact, he said the company is currently assessing a 280m mine shaft in Wales.

But I do like the concept of a non-nuclear heavy water, with a specific gravity of 2.5.

 

 

 

 

 

 

June 12, 2026 - Posted by AnonW | Energy, Energy Storage, Environment, Finance & Investment | Aviva, Barclays, Cap And Floor, Coire Glas Pumped Hydro, Department for Energy Security & Net Zero, Dinorwig Power Station (Electric Mountain), Gilkes Energy, Goldman Sachs, Insurance, Leasing, Loch Lomond, Loch Sloy, Loch Sloy Hydro-Electric Scheme, Loch Sloy Pumped Hydro, Long Duration Energy Storage (LDES), Ofgem, Peer-to-Peer Lending, Pumped Storage Hydroelectricity, RheEnergise, SSE Renewables, Water