Scientists are turning thin air into power storage

Five decades ago, engineers stumbled upon a potential clean power storage breakthrough. But the world soon forgot about it.

Now, with renewable electricity production overtaking coal for the first time, that old idea is back and looking stronger than ever: using liquid air to efficiently store excess renewable energy.

The problem: While fossil-fuel power plants can essentially switch on-and-off at will, renewable energy sources like solar and wind are intermittent.

• This means that sometimes there isn't enough electricity being generated, increasing the risks of power outages.
• On the flip side, sometimes there’s too much electricity created, which could damage the power grid.

A potential solution lies in liquid air energy storage. This process takes excess energy from the grid and uses it to cool air from the atmosphere until it liquefies (at -196°C), after which the liquid air is stored in insulated tanks.

• In times of high energy demand, this liquid air can be reheated so that it rapidly expands back into a gas, driving a turbine that generates electricity.

Cooler heads prevail

Liquid air is considered a more reliable option than the two main ways that power companies currently store excess renewable energy:

1. In lithium-ion batteries, which require rare metals
2. Via hydropower, which needs specific geographies for dam construction

Looking ahead…The world’s first liquid air energy storage facility, under construction by UK company Highview Power, will power up in 2026. It could provide enough backup electricity for ~200,000 homes once it comes fully online the following year.