That's always the problem with "green" energy (or actually, just about any generated energy) -- you can't store it for later usage. So some folks are proposing using a potential/kinetic energy sort of thing where an electric locomotive can move loaded cars uphill, then when more energy is needed, let them roll downhill and use the locomotive to generate electricity and put it back on the grid. An interesting idea, but how much energy can you actually store in a heavy train like that? How long is the downhill run? It sounds like much ado for only a few minutes worth of power.In April, the Nevada Bureau of Land Management granted environmental approval and a land lease to Advanced Rail Energy Storage (ARES), a startup with an energy storage solution that’s both novel and old-school. Apparently taking some inspiration from the myth of Sisyphus, ARES proposes to use excess off-peak energy to push a heavily-loaded train up a grade. Then, when the grid needs that energy back, the cars will be rolled back down the slope—but in a significant improvement on the myth, that return trip will generate energy and put it back on the grid.
ARES’ solution is related to an already common kind of energy storage known as pumped-storage hydropower, which pumps water uphill, then captures the power of its downhill flow as needed. The obvious advantage of the ARES approach is that it’s more adaptable, without the need for lots of water. ARES has also said its solution costs about half as much as other storage technologies, and claims 80% efficiency in energy reclamation, similar to or slightly above typical hydro-storage efficiency.
Garry K
