Alphabet Inc.'s secretive X R&D facility has revealed another idea that could help the world store the produced renewable energy in salt. Yes, that’s correct, salt. The research lab has recently brought together a prospect team to work on the salt storage under the project title ‘Malta’. The intermittent production of wind and solar energy forces many countries to dump their surplus energy at peak times in favour of the more reliable conventional energies, oil and coal, as well as natural gas ‘peakers’. Germany, for example, was forced to jettison 4 per cent of its renewable energy in 2015.
The good news is that thermal salt-based storage is much cheaper than lithium-ion batteries. So how does the salt storage work?
As Julian Green, the product manager for Malta, suggests the plant will comprise tanks filled with salt and others filled with antifreeze that will work combined “as a fridge and a jet”. At peak times, energy is taken in in form of electricity that is separated into streams of hot and cold air. The hot air heats up the salt, whereas the cold air cools the antifreeze, like a fridge. The jet is started when energy is in demand; then hot and cold air will rush toward each other, creating a blast of air that will power a turbine and generate electricity!
"If the moonshot factory gives up on a big, important problem like climate change, then maybe it will never get solved," said Obi Felten, a director at X. "If we do start solving it, there are trillions and trillions of dollars in market opportunity." X is stepping into a market that could see about $40 billion in investment by 2024, according Bloomberg New Energy Finance. Roughly 790 megawatts of energy will be stored this year and overall capacity is expected to hit 45 gigawatts in seven years, BNEF estimates.