British start-up leads world in energy storage
Highview is using ‘cryogenic’ liquid air to stockpile wind and solar power, Ambrose Evans-pritchard finds
The curse of intermittency for wind and solar power may be conquered sooner than almost anybody thought. A beautifully simple technology from a British start-up has slashed costs to levels that drastically alter the calculus of long-term energy storage.
Highview Power is pioneering the use of “cryogenic” liquid air to store electricity for long enough periods to cover the lulls in renewable energy. It appears close to doing so at levelised costs that will undercut competition from fossil fuel plants once scale is reached. Highview will almost certainly be the biggest company of its kind in the world by the early 2020s.
If it can deliver the full promise – big caveat – the cost breakthrough overcomes a key barrier for a global economy driven primarily by zero-carbon energy. One oft-repeated argument against Britain’s North Sea wind expansion falls away.
There are rival technologies in this field. Energy storage is a playground for hedge funds and venture capital, as fashionable as fintech. Siemens Gamesa is working on hot rock thermal storage. A team at Harvard is betting on organic flow batteries using death-defying “zombie quinones” from material such as rhubarb.
The US Energy Department’s ARPA-E programme is – despite Donald Trump’s rhetoric – still supporting a string of energy storage projects in league with top US labs and universities. The Japanese and Chinese are pursuing the great prize as well. Energy storage is not a fundamentally difficult challenge for science, and will be solved one way or another.
The race comes down to cost, simplicity and who can get there first with utility-sized plants. Highview’s chief executive, Javier Cavada, says nobody today can match his liquid air formula at gigawatt scale. “We are ready, we are scalable, we are much
cheaper and we are going to stay much cheaper,” he says.
The first viable Cryobattery is already up and running. A Highview plant is producing electricity for the local grid at a 15 megawatt/hour (MWH) plant in Bury, storing power during times of low demand and releasing it back when most needed. It is an arbitrage play on the variable costs of power.
The site shared with Viridor is tucked behind trees and is so discreet that my taxi had trouble finding it. The source of power is methane, from a local landfill in this case. In the future it will be wind and solar.
Highview cools air to minus 196C relying on the standard process used for the chemical industry for liquefied natural gas. As the air turns into liquid the volume is compressed 700-fold. This concentrate is then stored in insulated steel towers at low pressure. The liquid re-expands with a blast of force when heated and drives a turbine. Bingo: clean, dispatchable power on demand.
The beauty is that it can be scaled-up to provide unlimited storage at diminishing extra cost. “We’re like a hydro plant in a box. We can cover times when the wind doesn’t blow, One to two weeks is totally doable, even a month,” said Mr Cavada.
“The storage tanks are the cheapest component. It is the turbine that costs money. We can double the MWH for 30pc extra investment. As we get bigger the ratios change exponentially,” he said. The efficiency loss or “boil off ” rate from the storage vats is just 0.1pc each day. Much of this loss is recaptured by the closed system.
Last month the company teamed up with the US energy group Tenaska Power to build four vastly larger “gigawatt-scale” plants in Texas over the next two years, chiefly intended to back up Texan wind power. This is a revealing venture. Highview is competing toe-to-toe with gas “peaker” plants in a region of the world where pipeline gas is almost given away thanks to shale. If the sums work in Texas, they certainly work in Europe. Mr Cavada said the levelised costs for a one gigawatt (GW) plant comes in “way below” $100 (£82) per MWH. This is already cheaper than any other back-up option on the market, fossil or not. “In 10 years from now, I can see that being $50.” These are remarkable figures. Lazard estimates the levelised costs for gas peaker plants at $152-$206, new pumped-hydro at $152-$198, or a lithium-ion equivalent at $285-$581. Lithium batteries are superb for a few hours but the economics are not viable for utility power over long periods.
“Four hours is nothing for us, five is even better, six is fantastic, and at 10 we’re making music,” said Mr Cavada. Liquid air is well-suited to overnight back-up for solar farms in sunbelt zones. Highview teamed up with Spain’s TSK in March to develop gigawatt plants in Spain, South Africa and the Middle East.
In Britain it makes most sense for wind. The company hopes to launch a 250MWH project in North Yorkshire soon (awaiting clearance) as the first of a string of plants in the UK and Europe.
The technology is not magical. Liquefaction was around in the 19th century. Use for energy storage was first explored in academic papers in the Seventies. This came to little because it was not needed. It is urgently needed now. Renewables are reaching critical scale at a breathtaking speed.
Solving intermittency has leapt up the priority ladder for the UK grid. Renewables topped 50pc of the country’s power this summer at peak moments of combined wind and sun. The blackout on Aug 9 was linked to a systems glitch at Orsted’s 1.2GW Hornsea 1 wind farm off Grimsby.
Gas peaker plants offer quick back-up but they are costly to maintain and depend on LNG imports. Highview says liquid air can do the same job better. “We are faster than a gas plant” said Ed Scrase, the project manager.
The Government is targeting offshore wind capacity of 30GW by 2030. This may rise to 40GW given the plummeting costs achieved by the giant new turbines, smart blades and economies of scale. The last round of bids in 2017 came in at £57.50 per MWH. The next set later this month may be closer to £50 and below market spot prices. Subsidies turn into revenue for the Exchequer.
The Committee on Climate Change wants to go for broke with 75GW of offshore wind to meet the UK’S net-zero 2050 target. Such scale means a wash of surplus power in the middle of the night or at times of low demand. This implies “free” or ultra-cheap electricity for energy storage, since otherwise it would have to be curtailed by shutting down turbines – “off-peak waste electricity” in the trade jargon. The UK plans makes cryogenic liquid air almost unbeatable.
The excess power can of course be used as well to make hydrogen green gas through electrolysis for trains, trucks and home heating. This may be
‘We are ready, we are scalable, we are much cheaper and we are going to stay much cheaper’
necessary, but it is trickier. Mr Cavada said the “round trip” efficiency of the Highview process so far is 60pc (ie two fifths is lost). This can be raised to 70pc with the capture of wasted heat from industrial plants. It is safe and clean. “We have no combustion particles, and no risk of explosions,” he said.
Liquefaction extracts CO2 from the air as a by-product. The gas turns into solid dry ice. “We capture all the carbon and we can sell it,” he said. Several companies around the world are devising ways to turn CO2 into bricks or carbon-rich concrete.
Highview began in 2005 with the help of Leeds University at a time when few energy analysts – beyond a handful of tech-visionaries – had any idea how quickly renewable costs would reach fossil parity. The venture was backed by £12m of state grants from the Government and Innovate UK.
It is chiefly funded by “angel investors”, City tycoons doing their bit to save the environment. Normally they are resigned to losing money. On this occasion they may get a bumper reward for virtue.
Expansion has reached take-off. The company is in talks to build 20 large plants over the next three years. “We will be the biggest energy-storage company on the planet,” he said.
It is something to cheer us up as the Amazon blazes.