New Atlas – The new system, which the team calls Thermal Energy Grid Storage-Multi-Junction Photovoltaics (TEGS-MPV), is based on the molten salt batteries that sit at the heart of grid-scale energy storage systems like concentrated solar. But there are a few problems with salt as a storage medium – for one, it becomes quite corrosive when the heat is cranked up.

“The reason that technology is interesting is, once you do this process of focusing the light to get heat, you can store heat much more cheaply than you can store electricity,” says Asegun Henry, lead researcher on the study. “This technology has been around for a while, but the thinking has been that its cost will never get low enough to compete with natural gas. So there was a push to operate at much higher temperatures, so you could use a more efficient heat engine and get the cost down.”

Alphabet’s hot salt energy-storage project becomes its own company (Google – Alphabet)

Malta is working on a megawatt-scale pilot plant.

Alphabet’s X division has played host to a string of experimental ideas, and another one is spinning out as an independent business. Malta uses cheap, abundant materials including salt, anti-freeze and steel to store power at grid scale.

Malta taps into the laws of thermodynamics to store renewable and fossil energy as heat in molten salt and cold in low-temperature anti-freeze until it’s needed — you probably still need electricity at night, when the sun isn’t shining on your local solar farm. The company is working on a pilot plant, backed by $26 million from its first funding round, which was led by a fund Jeff Bezos, Bill Gates and Michael Bloomberg are involved with.

Power storage is often a cumbersome, expensive problem, particularly for the likes of wind and solar farms. Providing them with a reliable, inexpensive way to keep electricity in reserve could cut down on waste, while helping renewable energy companies find the bandwidth to generate more power.