Without the capacity to store renewable power, the default position will be to rely on imported gas. However, the vulnerability of that strategy is now being cruelly exposed with soaring prices which are already hitting consumers. It is a toxic mix – politically, environmentally, and economically.
Last week’s unseasonably low wind energy production, coupled with a fault at an 800MW gas plant, meant the UK had to fire up its coal energy power plants, boosting this ‘dirty’ form of production from zero to five per cent.
Almost overnight, wind energy’s contribution had dropped to just two per cent of the mix, from 21 per cent the previous week. With the gas wholesale price at a record high, coal became the cheapest solution – which the National Grid is obliged to find when “events” like these occur.
Without finding a way to store energy to handle the peaks and troughs of intermittent renewable energy, it will be difficult for the UK to reduce dependence on gas and coal-fired plants and meet our climate obligations.
There has been much fanfare for new energy storage technologies like hydrogen. This has been talked about for decades and will doubtless become a serious player at some stage.
Meanwhile, however, a solution lies in a technology which already provides 95 per cent of the world’s energy storage – pumped storage hydro.
This form of storing energy turns electricity into stored – or potential – energy and then back again to electrical energy. Electricity pumps water from a lower reservoir to a higher reservoir at times when there is more energy being produced on the grid than is needed. This energy is stored until it is required, and the water then is allowed to flow back through a hydro-turbine, generating electricity to meet sudden or predicted spikes in demand.
Hydroelectricity has been part of our landscape in Scotland since 1934 when the Laggan Dam was built to provide power for aluminium smelting plants at Kinlochleven and Lochaber.
The last large-scale pumped storage plant in Scotland was built at Foyers on Loch Ness. It was commissioned in 1974. These were created to solve a similar problem of the time: what to do when excess power was being generated that was not required. Back then, it was not from sources of renewable energy but from nuclear power stations.
Pumped storage provides 2.8GW of the 4GW of energy storage currently available in the UK with batteries making up the majority of the rest. My company, ILI Group, aims to double the capacity that comes from pumped storage in the coming years.
Unlike battery technology, however, pumped storage hydro can provide this power over many hours or even days. This type of ‘long-duration’ storage must now be seen as crucial in enabling the further deployment of renewable energy projects across the UK. It is completely irrational – as recent weeks have confirmed – to keep funding renewable capacity without also providing the necessary non-fossil fuel back-up.
The UK government has recognised the need for action by releasing the Smart Systems and Flexibility Plan 2021, alongside a call for evidence on the merits of long-duration storage. The technology is not in doubt but the means of funding the initial investment needs to be addressed, though there is no ongoing need for subsidy.
National Grid ESO, the electricity network operator, has estimated that there could be a requirement for more than 13GW of energy storage required by 2030 and over 40GW of energy storage by 2050.
There is currently some 5GW of pumped storage hydro projects in the pipeline in the UK, which would equate to an injection of £3 billion into the economy.
Planned projects include SSE’s 1500MW Coire Glas near Loch Lochy in the Highlands, Buccleuch’s 400MW at Glenmuckloch in Dumfries and Galloway, and three of ILI’s own projects, a 450MW scheme, called Red John, on Loch Ness, a 600MW one named Corrievarkie at Loch Ericht and an 800MW project called Balliemeanoch at Loch Awe. These projects will help off-set hundreds of millions of tonnes of carbon dioxide over their lifetimes.
Pumped storage hydro makes complete sense from every perspective – in terms of security of supply, as a non-fossil fuel back-up to renewable generation and also a proven technology, that does not require us to wait for a solution. Added to that is the fact that it will create substantial employment with thousands of construction jobs.
Imperial College London has estimated that the addition of 4.5GW of pumped storage could save £690 million a year in operator costs by 2050. In addition, instead of paying constraint charges for wind farms to switch off during times of high wind and low demand, that energy can instead be captured, stored, and made available when needed.
In the year of the United Nations’ Cop26 climate summit, the UK government needs to put in place the market mechanisms which will bring these projects to fruition and without which they cannot happen.
The main alternative to long-duration storage is increased reliance on imported gas and, as the last few weeks have confirmed, that is an exceptionally bad idea.
Mark Wilson is chief executive of Intelligent Land Investments Group. The ILI Group is a Scottish company at the forefront of green energy storage