Alphabet creates an energy storage system with the use of salt
The American multinational giant Alphabet is developing an innovative storage technology solution for renewable energy using salt and antifreeze.
The recently disclosed initiative with the code name ‘Malta’ is being developed through Alphabet’s experimental ‘X’ division and mixes an established technique with newly designed components.
Julian Green, the product manager for ‘Malta’ said: "Think of this, at a very simple level, as a fridge and a jet”.
The system takes in energy in the form of electricity and turns it into separate streams of hot and cold air, with two tanks being filled with salt, and two being filled with antifreeze or a hydrocarbon liquid.
The hot air heats up the salt, while the cold air cools the antifreeze, a bit like a refrigerator.
The process reverses through the jet engine part, allowing hot and cold air rush toward each other, creating powerful gusts that spin a turbine and spit out electricity when the grid needs it.
Salt maintains its temperature well, so the system can store energy for a period ranging from hours to days, depending on how well the tanks are insulated.
Alphabet’s solution to contain just captured electricity as thermal energy is an idea developed by Nobel prize-winning Stanford physics professor Robert Laughlin who created the theoretical foundations of a system that stores electricity as heat (in high temperature molten salt) and cold (in a low temperature liquid similar to the antifreeze you have in a car).
The storage technology can be easily located almost anywhere, and has the potential to last longer than lithium-ion batteries and compete on price with new hydro pumped storage plants and other existing clean energy storage methods, according to ‘X’.
According to the scientific community, Malta’s contribution to the storage technology was to design a system that operates at lower temperatures so it doesn't require specialised, expensive ceramics and steels.
Green commented: "The thermodynamic physics are well-known to anyone who studied it enough in college” adding “The trick is doing it at the right temperatures, with cheap materials. That is super compelling”.
Raj Apte, Malta's Head Engineer revealed that the thermal salt-based storage also has the potential to be several times cheaper than lithium-ion batteries and other existing grid-scale storage technologies.
Bloomberg New Energy Finance analyst Yayoi Sekine said: "It could potentially compete with lithium-ion, but there are a lot of challenges that an emerging technology has to face" referring to low oil and natural gas prices, a market reality that has affected several companies working on alternatives to fossil fuels.