UK liquid air energy storage plant receives funding

The announcement that two liquid air-based facilities are among the 12 projects to share £500,000 for feasibility studies into a range of energy storage systems comes as a new report argues cryogenic technology could create a £1bn industry and 22,000 jobs in the UK.

Other concepts through to the first round of the competition include storing energy at a grid level using flywheels, compressed air, methane production, various industrial and domestic-scale batteries, and a system that transports buckets of gravel up a hill.

It’s not much bigger than the Slough plant but the capacity of the process is about 10 times bigger

Energy storage is seen as a vital aspect of plans to reduce carbon emissions by making renewable energy generation more practical, for example storing excess electricity created when the wind is blowing for use at peak times when it isn’t.

But apart from a small amount of pumped hydro storage, the UK has yet to roll out energy storage at a grid level, and the competition is seen as a way of encouraging the development of a range of technologies to meet this need.

Highview Power Storage has developed a technology for using electricity to liquefy air that can later be evaporated to drive turbine generators and has been operating a pilot plant in Slough since March 2011.

The firm has now put forward proposals for two plants that have won competition funding, including its first commercial-scale facility storing energy from the National Grid when it is needed, on which construction could start as early as July if the plant gets through to the next stage of the competition.

The plant would be hosted at National Grid’s Grain Liquefied Natural Gas (LNG) import terminal on the Isle of Grain in Kent, where the hot and cold energy waste streams produced by gas liquefaction could be used to make the energy storage process more efficient.

‘Physically it’s not much bigger than the Slough plant but the capacity of the process is about 10 times bigger,’ Highview CEO Gareth Brett told The Engineer. ‘We’ll be able to generate around 5MW of electricity and run for around six hours.’

We’ll be able to generate around 5MW of electricity and run for around six hours

He added that it was hard to say exactly how much the waste streams would improve the efficiency of the process but that the company expected overall efficiency of the plant to be around 50 to 60 per cent, enough to make the facility commercially viable. The final cost of the plant has yet to be determined.

‘It’s a significant improvement. Generally we wouldn’t expect to get that sort of efficiency until we were at really quite a large system, 20MW that kind of thing.’

Highview’s second competition-funded study is for a ‘CryoGenset’ system at a landfill gas generation plant in Canterbury that acts like a diesel generator but fuelled by liquid air brought in by truck from a separate liquefaction site, with efficiency improved by the gas plant’s waste heat.

A report published today by the Centre for Low Carbon Futures run by a consortium of British universities found 15GW of liquid air energy storage could reduce grid emissions at peak times by up to 4.5 per cent, while 30GW would cut them by up to 20 per cent.

It argues that the UK has a manufacturing capability that is well suited to producing liquid air systems and greater use of the technology could generate £1bn per year for the UK economy by 2050 and support 20,000 jobs.

The Department of Energy and Climate Change (DECC) plans to invite some of the energy storage competition winners to take part in the demonstration phase later this year and share in a further £17m available for testing technology designs.

As well as revealing the 12 phase one competition winners, the government has also announced the four recipients of a total £1.5m for improving components or materials used for energy storage systems and for exploring how storage systems can be used in the UK electricity network.

A further 30 projects have been awarded a share of up to £16m under the first phase of the Energy Entrepreneurs Fund to support various cleantech startup companies, and another 15 groups will share £3m for feasibility studies and demonstrator projects to help develop domestic heat storage technologies.