Storing Excess Power Using Gravity

In the Tehachapi Mountains of California, an electric railcar moves uphill on a small track. Carrying a four-ton concrete pad, the small test vehicle could unlock the future of alternative energy.

Developed over the last three years by Entrepreneur Bill Pietzke and Engineer Matt Brown, Advanced Rail Energy Storage (ARES) provides energy storage, which allows green energy—solar and wind power—to be grid-ready even when the wind isn’t blowing and the sun isn’t shining.

How does it work? —It stores wind and solar power using a railbox full of rocks and the power of gravity. A fleet of electric traction drive shuttle-trains, operating on a closed low-friction automated steel rail network transports a field of heavy masses between two storage yards at different elevations. ARES uses excess solar and wind energy to go up hill, but when it comes back down, the rail’s motor becomes a generator itself and the vehicle produces electricity and gives it back to the grid.

Energy storage is a key component to reliable alternative energy. While solar and wind power provide sustainable benefits to our climate, health and economy, they are at the mercy of wind and sun, which are not always available.

In the past, dams were used to store energy. This new technology, however, no longer relies on water, has multiple location opportunities and has an easier environment permitting and regulatory review process than dams. 

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