Gravity Provides Grid-scale Storage

California-based Advanced Rail Energy Storage (ARES) has received a right-of-way lease from the U.S. Bureau of Land Management for a gravity-based, commercial-scale rail energy storage project on 106 acres of public land in southern Nevada. The 50-megawatt design is expected to provide 12.5 MWh of energy for grid stabilization. Energy will be stored and released for dispatch to the western grid via the Valley Electric Association.

Excess power produced by solar and wind energy systems will be tapped to move multiple electric locomotive cars up a track sited on a gentle grade. When power is needed, the cars will move downhill, using their motor-generators to return power to the electricity grid.

The ARES fast-response technology is designed to bridge the power gap between large battery and flywheel installations and far larger pumped-storage hydro – at a lower life-cycle cost than batteries, a higher energy-to-power ratio than flywheels and a greater efficiency and far faster ramp-rate than pumped storage.

The system is considered to have minimal environmental implications relative to other utility-scale storage options, because it relies on existing, proven technology, consumes no water resources, and requires no dam or tunnel construction. The service life of the $55 million Nevada project is anticipated to be 40 years.