Google Looks to Salt and Antifreeze for Renewable Energy Storage

CC BY-ND 2.0. Donahos

Alphabet, Google's parent company, has an experimental X division that focuses on pie-in-the-sky projects that seem at times far fetched, but could solve many of the world's problems. This division gave birth to Google's self-driving car and Project Loon, the Wi-Fi carrying high altitude balloons and now it has set its sights on better high density energy storage.

The new project called Malta consists of molten salt storage, which has been a promising energy storage concept for a while, paired with cold storage using antifreeze. Molten salt storage can store energy for days, even weeks, making it an ideal solution for renewable energy which, at the moment, in most places has to be used or lost.

According to Bloomberg, California has already had to dump off 300,000 megawatt hours of excess electricity from the grid this year that came from renewable sources. If that energy could have been stored, tens of thousands of homes could have been powered. Germany throws away 4 percent of its wind energy annually and China tosses 17 percent.

project malta

© X

The advantages of this dual thermal energy storage technology is that it can store high densities of energy and it's likely to be far less expensive than the scale equivalent of lithium batteries. It can also be easily scaled up by adding more salt and cold liquid tanks and the salt can be charged and re-charged many times over 40 years.

X has built a small-scale prototype of this storage technology in Silicon Valley and is looking for large business partners like GE or Siemens that could develop it into a commercial prototype to test it on the grid. While the project is ambitious, X thinks it's important and a sound business venture.

"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, to Bloomberg. "If we do start solving it, there are trillions and trillions of dollars in market opportunity."

The X team is currently tinkering with materials and building methods to come up with the best iteration of the technology.