With more solar and wind power on the grid, we’ll need lots of energy storage to soak up any surplus power for use during windless nights or cloudy days. Batteries are getting a lot of attention, but “gravity trains” may be an option as well.
The ARES system is basically a series of heavy concrete blocks on a railway. The excess power from the grid pushes those blocks up an incline. When demand puts a strain on the grid, these blocks are released and go back down the incline. Through the magic of regenerative braking, that kinetic energy gets converted into an extra jolt of electrical current for the grid.
Each of the trains weighs about 300 tons, and they work best on an incline grade of 7.2%. As each train moves down the incline, they pump about 50MW of power into the grid.
The obvious limitations are the need for space and inclines. But it could be a good solution for some of the hilly or mountainous regions in western states like California. I’m glad to see the company is still moving forward with its technology, as we’ll need all sort of energy innovation to solve the storage needs.
Meanwhile, you can watch this Bloomberg news segment on the company: