Alphabet, the parent company of Google, has a so-called X division, which works on highly experimental projects. But a lot of these projects could prove very beneficial in solving some of the world’s biggest problems. This division created Google’s self-driving car, as well as Project Loon, which involves high altitude balloons carrying Wi-Fi. And now it is looking for more efficient and effective ways of high-density energy storage.

This project is called Malta and the energy storage solution they came up with features molten salt storage, which X has paired with cold storage using antifreeze. Molten salt energy storage has been looked at before as a viable solution for energy storage, and paired with antifreeze, it can store energy for days, possibly weeks. As such, it would be perfect for storing renewable energy, which is simply getting discarded in lots of places at the moment.

Reports show that China discards 17 percent of energy produced by wind per year, while Germany tosses away 4 percent. And this year alone, California has had to discard 300,000 megawatt hours of excess electricity from the grid, all of which came from renewable sources. If there was a way to store that energy, it would be enough to power thousands of homes.

The dual thermal energy storage tech that X has come up with can be used to store high densities of energy, while it will also be a lot less expensive than existing solutions. It is also very scalable, since all it would take to expand it would be adding more salt and cold liquid tanks to the system. Also, the salt used can be charged and re-charged several times over its lifespan.

They’ve already built a small prototype of this energy storage system in Silicon Valley. They’re now looking for partners, such as Siemens and GE, to develop a commercial prototype, which can be tested on the grid.