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 | Energy, Energy Storage, Environment, Finance & Investment | , , , , , , , , , , , , , , , , , , , , | 2 Comments

How Much Pumped Storage Hydro Will Be Operational In The UK By 2030?

Pumped Storage Hydro is the Bank of England-standard for energy storage.

I asked Google AI, the question in the title of this post and received this answer.

The UK currently has approximately 3 GW (roughly 26-28 GWh) of operational pumped storage hydro (PSH) capacity. By 2030, this capacity is expected to increase, driven by new projects in the pipeline that aim to meet a government goal of up to 8 GW of long-duration energy storage by that year.

Key Projects Expected Online by 2030-2031:

Coire Glas (SSE): A major project in Scotland with a planned capacity of 1.3 GW / 30 GWh, expected to be operational around 2030–31.

Cruachan Expansion (Drax): A 600MW plant in Scotland that has received approval, with construction expected to contribute to the 2030 goal.

Glenmuckloch: Projected to be operational by 2029. In 

Other Developments:

Total Pipeline: Developers have identified up to 10 GW of potential projects in the Scottish Highlands and Wales, though not all will be operational by 2030.

Future Growth: The total installed capacity of PSH is expected to grow significantly, with one projection suggesting a rise from 26.7 GWh currently to over 122 GWh by 2034.

To support these projects, the UK government has confirmed a “cap and floor” investment framework to stimulate development of long-duration energy storage (LDES).

For a relatively small island we do seem to be an ideal place to develop pumped storage hydro!

The Coire Glas Pumped Storage Scheme

In The Coire Glas Pumped Storage Scheme, I give more details of this scheme.

The Glenmuckloch Pumped Storage Scheme

In The Glenmuckloch Pumped Storage Scheme, I give more details of this scheme, which is based on a disused open cast coal mine.

Addition Of Pumped Storage Hydro By 2030

This looks to be around 5 GW, but it is just a foretaste of the shape of things to come!

February 28, 2026 Posted by | Artificial Intelligence, Energy, Energy Storage | , , , , , , , , , , , , , , | 1 Comment

UK Government Sets 8-Hour Minimum For LDES Cap-And-Floor Sheme

The title of this post, is the sa,e as that of this article on Energy Storage News.

This is the sub-heading.

The UK government has published a Technical Decision Document confirming crucial aspects of its long duration electricity storage (LDES) cap-and-floor scheme, which includes increasing the minimum duration required from six hours to eight

These paragraphs give full details.

The document, released by regulator Ofgem on 11 March, details the final overarching rules and requirements for the scheme as well as how it will be implemented, though significant detail still remains to be worked out.

The scheme will provide a cap-and-floor revenue protection for 20-25 years that will allow all capital costs to be recoverable, and is effectively a subsidy for LDES projects that may not be commercially viable without it. Most energy storage projects being deployed in the UK today are lithium-ion battery energy storage systems (BESS) of somewhere between 1-hour and 3-hour in duration (very occasionally higher).

One of the most significant new details of the scheme is that, following industry feedback, the minimum duration for projects to qualify has been increased from six hours to eight hours of continuous rated power.

The ‘continuous rated power’ aspect prevents shorter duration projects from bidding in a smaller section of their MW capacity in order to act like an 8-hour system.

Another interesting detail pointed out by several commentators is that the cap is a ‘soft’ one, meaning it will allow extra revenue to be shared between developers and consumers. Exact details on the ratio are yet to be determined.

As a Graduate Control Engineer from Liverpool University in the 1960s, I hope that the move from a six to eight hours  minimum duration is feasible.

I wasn’t dealing with power systems, but with multi-vessel chemical plants.

These are my thoughts.

The biggest project, I was dealing with a few years later in the 1970s, was the modeling of all the the reservoirs and pipelines by the Water Resoures Board.

As the supply side of the water industry hasn’t had too many issues with the volume of water supplied, I feel that the main modelers must have done a reasonable job.

Six To Eight Hours Of Continuous Operation

The article says this about uprating from six to eight hours of continuous operations.

All the systems that have been proposed for cap-and-floor operation, seem to have some form of physical storage.

  • Energy Dome appears to have tents of carbon dioxide.
  • Energy Vault uses stacks of heavy weights.
  • Form Energy has tanks of rust.
  • Gravitricity has huge weights in disued mine shafts.
  • Highview Power has large tanks of liquid air.
  • Pumped storage hydro has two lakes, that hold water.
  • Rheenergise has two large tanks, of a  water-based slurry.

So to go from six to eight hours will hopefully just need some more storage.

Highview Power appears to use similar gas tanks to those used to store natural gas or hydrogen.

This image clipped from Highview’s web site, shows large tanks for liquified gas storage.

With tanks like these, which can hold GW-equivalents of liquid air, Highview could be building batteries with storage to rival the smaller pumped storage hydroelectric power stations. They are already talking of 200 MW/2.5 GWh systems, which would have a 12.5 hour continuous rating and would probably need two to three tanks.

Coire Glas Pumped Storage

I’ll use Coire Glas pumped storage hydro electric power station as an example.

As currently planned SSE’s Cioire Glas  pumped storage hydroelectric power station is 1.5 GW/30 GWh, so it has a a 20 hour continuous rating.

In The UK’s Pumped Storage Hydroelectricity, I gave a rough estimate of the pumped storage hydroelectricity systems in operation or planed as nearly 11 GW/224GWh.

The Soft Cap

The article says this about a soft cap.

Another interesting detail pointed out by several commentators is that the cap is a ‘soft’ one, meaning it will allow extra revenue to be shared between developers and consumers. Exact details on the ratio are yet to be determined.

I seem to remember that when I was modeling a larger multi-vessel chemical plant at ICI, I was using sharing between vessels, to get the system to operate on a PACE-231R analog computer.

So I suspect a soft cap is possible.

 

March 18, 2025 Posted by | Energy, Energy Storage | , , , , , , , , , , , , , , | Leave a comment

UK To Fund Hydro Energy Storage Projects

The title of this post, is the same as that of this article on The Times.

This is the sub-heading.

New infrastructure aims to help balance the electricity system after the rapid growth in renewables

These three paragraphs infrastructure the article.

Projects that use water to store and release energy are to be given government support, in an attempt to help manage the volatility in supply and demand as more green power enters the grid.

From next year, pumped hydro storage projects will be able to apply for government subsidies, which will be provided via a “cap and floor” mechanism. These would guarantee revenues if prices drop below a certain floor but prevent providers from charging above a ceiling when power prices are high.

Like other government support schemes, any cost will be levied on energy bills, while consumers will be paid back any money generated above the cap. It is yet to be decided precisely how the cap and floor will be set.

I feel it is reasonable to expect the system to be a success, as a similar system is used for interconnectors and this article on Offshore Energy is entitled Over $86 million To Be Split Between UK and Belgium Consumers As 1 GW Subsea Interconnector’s ‘Remarkable’ Revenues Exceed Ofgem’s Cap.

It looks like Ofgem played this right for interconnectors and the Nemo Link is making a substantial payment.

It will be interesting to see what happens when “cap and floor” contracts are assigned.

This move by Ofgem will probably have effects in two areas.

  • SSE, Statera and Statkraft, who are typically developing systems at the high end with a size of about 1.5 GW/25 GWh could find money is easier to come by.
  • At the lower end, companies like Highview Power, who have systems of 50 MW/300 MWh and 200 MW/2.5 GWh under development, will also benefit.

My Control Engineering thoughts are leaning towards the 200 MW/2.5 GWh systems being the popular ones. Especially as they would appear to be close to the right size to support a 1 GW wind farm for two hours.

A Highview Power Two-Hour Liquid Air Battery could fit nearly with a fleet of Two-Hour BESS.

It should be noted that CAF use a little-and-large approach to theit battery-electric trams in the West Midlands.

A large lithium-ion battery is the main storage device.

A supercapacitor handles the high-frequency response and keeps the power steady.

Pairing a Highview Power Two-Hour Liquid Air Battery and a Two-Hour BESS could achieve the same performance and possibly result in some cost savings.

 

October 11, 2024 Posted by | Energy, Finance & Investment | , , , , , , , , , , | Leave a comment

Cap And Floor Mechanism The ‘Standout Solution’ For Long Duration Storage, KPMG Finds

The title of this post, is the same as that of this article on Current News.

These are the first two paragraphs.

A cap and floor regime would be the most beneficial solution for supporting long duration energy storage, a KPMG report has found.

Commissioned by Drax, the report detailed how there is currently no appropriate investment mechanism for long duration storage. Examining four investment mechanisms – the Contracts for Difference (CfD) scheme, Regulated Asset Value (RAV) model, cap and floor regime and a reformed Capacity Market – it identified cap and floor as the best solution.

Cap and floor has been used successfully in the financing of interconnectors, so perhaps to apply it to long duration energy storage, will lead to greater use of such storage.

January 12, 2022 Posted by | Energy Storage, Finance & Investment | , , , , | Leave a comment