To clean the grid, we’re going to need lots of energy storage to capture surplus renewables and dispatch them when the sun isn’t shining and the wind isn’t blowing.  This market for energy storage technologies is growing rapidly, helped by battery innovations spurred in part by electric vehicle deployment.

But batteries aren’t the only way to store energy, and the recent push is spurring some creative ideas.  As an example, gravity could be used in more ways than just pumping water uphill for pumped hydro storage, according to Business Green:

The ARES [Advanced Rail Energy Storage] Nevada project uses the same principles as pumped hydroelectric energy storage projects, but instead of relying on water in a water-stressed region it plans to make use of an inclined rail track and generator locomotive cars that will run along it.

Once operational, the project will encompass 106 acres of public land in Southern Nevada, near Pahrump in Clark and Nye Counties. ARES plans to connect the energy storage system to the power western grid via the facilities of Valley Electric Association, providing grid stabilization services to the region.

It reminds me of a pumped hydro example I read about using the tides: an enclosed container fills up at high tide with seawater, and then the height differential created with low tide allows the water to spill out and spin a turbine. I guess you could call that Tidal Energy Storage.

Either way, it’s encouraging to see some creative and hopefully low-cost projects that could help us solve the energy storage challenge.