The 50MW, 250MWh CRYObattery plant, based in the UK, will use a decommissioned thermal power plant to produce a never-before-seen large-scale solution that could solve the challenge of storing renewable battery power.
The plant is planned to address issues stressing the UK grid (such as reduced inertia due to thermal plant retirements and intermittent power from renewable energy sources), allowing the country to reach its decarbonisation goals. But can the plant deliver on its promises?
Highview Power's concept art showing its planned CRYObattery liquid air energy storage plant, which will be based in the North of England. Image Credit: Highview Power.
What Does Highview Power Hope to Achieve Through its Power Plant?
The UK, along with the rest of Europe, has a goal to decarbonise industry, power, heat, and transport—which is no mean feat. Ultimately, to build a fully carbon-free future, long-duration, giga-scale energy storage is required to support baseload renewable energy.
The biggest challenge of supporting renewable energy, primarily wind and solar power, is that natural resources are variable. As the supply therefore can’t be controlled, the grid needs to be adapted to incorporate the resultant fluctuations. The grid needs lots of flexibility and ways to balance these out. The Highview plant is meant to address such requirements by repurposing equipment from conventional energy infrastructure to ultimately see the integration of renewables into the grid.
A thermal energy storage plant. An example of an alternative to liquid air energy storage. Image Credit: Wikipedia.
What are the Alternatives to Liquid Air Energy Storage?
Lithium-ion batteries have been dominating energy storage for some time, especially given their increasing capabilities to work on a large scale. In addition, lithium-ion energy density and safety have continued to improve while costs continually reduce. However, the periodic influxes of renewable energy sources create a prolonged demand that is economically impossible for lithium-ion batteries to process.
Predictions are that solar and wind plants are to receive 73% of all new power capacity investment globally until 2050. This means that the chosen energy storage needs to span weeks—or even months—rather than just minutes or hours.
While Highview Power has used liquid air energy storage (LAES) for its plant, there are other alternatives:
Concentrating solar plants capture heat and store energy in water, molten salts or other fluids. Stored energy is then used to generate electricity.
Compressed Air Energy Storage
CAES systems compress air using electricity during off-peak times and then store that air in underground caverns. Air can then be drawn from storage and fired with natural gas in conventional turbines.
Excess electricity can be used to create hydrogen—for it to then be stored and used later in fuel cells, engines or turbines to generate electricity without producing harmful emissions.
Pumped Hydroelectric Storage
Energy can be stored at the grid’s transmission stage by pumping water into the upper reservoir—thereby storing excess generation. Water is then released on demand, running through turbines to generate electricity.
A cylinder-shaped device, which contains a large rotor inside a vacuum, enables electricity to be stored in the form of rotational energy. To discharge the energy, the rotor slows down and runs on inertial energy, thereby returning electricity to the grid.
Work is underway to try to turn electricity, water and air into carbon-free ammonia. The ammonia can then be stored in tanks and burned on demand to generate electricity.
What Sets the Highview Plant Apart?
Unfortunately, the alternatives that have been trialled, including liquid air storage, have to date produced more bankruptcies and small-scale pilots than large-scale successes. However, Highview has a different approach. It has already completed a test plant and is now using equipment developed for the conventional power, oil and gas industries to liquefy gas, store it, and ultimately produce electricity on demand.
A colour-coded diagram of the Highview Power plant's renewable power storage and production process, which is formed of three major phases: 'Charge' (the conversion of ambient air into liquid), 'Store' (the storage of that gathered liquid air within tans), and 'Recover' (the expansion—when needed—of the 'liquid air' into a gas for electricity generation. Image Credit: Highview Power.
Unlike the alternatives, Highview’s technology doesn’t rely on special geological formations; rather, it avoids the hurdle of maintaining infrastructure at high pressure, and it has proven to be far more cost-effective than the alternatives in its trials. If the plant is successful and works on the large scale, Highview would most certainly jump ahead of the pack of long-duration storage companies and really begin to challenge lithium-ion’s market dominance.
The Benefits of Liquid Air Energy Storage Technology
With support from the UK Government and business partners, Highview Power has been able to successfully design and build the world’s first grid-scale LAES plant. The plant is the only large-scale, long-duration, energy storage technology that has been produced so far at an acceptable cost. LAES technology will potentially offer utilities around the world to transition to a low-carbon society.
LAES has proven successful due to the following core benefits:
It Uses Existing Sites
As reflected by the Highview plant, LAES can use decommissioned sites with existing mature components (such as liquefiers and power turbines) that have proven performance, cost and lifetime.
It is Suitable for Large Energy Stores
LAES isn’t restricted by geography and can store anything from about 20MWh to over 1GWh’s worth of energy.
It Integrates with Other Industrial Processes
LAES plants can use both waste heat and cold to enhance performance.
A liquid air energy storage (LAES) plant (made by Air Liquide) in Ontario, Canada.
LAES technology promises to deliver economies of scale that have never before been possible with any other energy storage methods—and such a development is likely set for deployment at a commercial scale. If the Highview plant is successful, it could have a huge impact on a global scale.
Will the Highview Plant Succeed?
The Highview plant shows great potential, not least because it is based on real-life results rather than black-box technology and laboratory-based experiments. The new plant is a grid-scale project, which is a step forward from the previous pilots, but it still needs to prove itself to offer the long-duration storage it promises.
The technology needs to demonstrate its effectiveness for grid-balancing, such as in terms of its short-term operating reserve and peak load capacity. However, the Highview Plant is set to do just that. The plant will be the first operational demonstration of LAES technology at grid scale. As the only freely locatable energy storage solution on the market that delivers clean, reliable and cost-efficient energy, for weeks instead of days, it certainly looks set for success.
If it delivers, it will help to provide the UK with a clean energy system well into the future and will help deliver on the government's modern Industrial Strategy—ultimately paving the way for the wider adoption of LAES technology globally.