A group of researchers at the Massachusetts Institute of Technology (MIT) say liquid metals could provide the solution to the solar energy-storage problem, ensuring that the power is available at all times and not just when the sun is shining. 

The researchers are working on commercializing liquid-metal batteries that can store energy for less than $500 per kilowatt-hour. The group launched a startup company, Ambri Inc., and believes it has found an alternative to pumped-
water systems that currently comprise about 95 percent of the country’s energy-storage capacity.

MIT researcher Donald Sadoway said a new storage technology could change renewable energy. 

“If we can get liquid-metal batteries down to $500 a kilowatt-hour, we’ll change the world,” Sadoway said. 

The researchers say that, at about one-third the cost of some battery technologies, Ambri technology would enable wind- and solar-project developers to bring energy to the grid at all times, increasing its reliability. 

The company plans on installing its first two prototypes at a Massachusetts military base and a Hawaiian wind farm by next year. 

Ambri also recently won a $250,000 grant from New York state to develop and test a prototype battery with Con Edison, a major U.S. electric utility.

According to Ambri’s website, the liquid-metal battery technology performs like a tractor and a race car, responding to regulation signals in milliseconds. It can store up to 12 hours of energy and discharge it over time.

Sadoway said he is not concerned with competition from lithium-ion batteries, deeming them a better fit for cars and portable devices as opposed to the large storage systems that feed the grid. 

“Lithium-ion plants are too expensive to build, and it makes no sense to string 
a bunch of these tiny things together,” 
he said.

Sadoway added that his batteries will be able to be delivered on a truck instead of the pumped-hydro systems that require a hill, a hydropower plant and a lot of water. According to the U.S. Department of Energy, there are 23.4 gigawatts of pumped-hydropower capacity in operation, compared to about 304 megawatts of battery storage. 

“Ours won’t have any geographical constraint,” Sadoway said.