R. Weed
Advanced Rail Energy Storage,
United States
Keywords: gravity, energy storage
Summary:
Various technologies have been deployed for storing and dispatching gravitational potential energy, including the most prevalent form of energy storage by far, pumped hydro. Pumped hydro has multiple advantages, including an 'active species' (gravity) which is free, ubiquitous, non-degrading, non-flammable, and not subject to temperature; essentially no emissions; and long and short duration capabilities. Pumped hydro, though, also has a number of disadvantages such as large construction costs, long permitting time, permanent land impact, and extensive water use. Rail-based energy storage is akin to pumped hydro, with rails above ground moving solid materials instead of pipes above or below ground moving water. Yet rail-based energy storage has the indicated advantages of pumped hydro, without the enumerated disadvantages.