SoylentNews is people
SoylentNews
The easiest way to squirrel away electricity in times of plenty, for use when it is scarce, is to pump water uphill with it. Such pumped storage is widely employed where local geography and hydrology permit, but it does need two basins, at different heights, to act as reservoirs, and a supply of water to fill them.
[...] Where geography does not favour pumped storage, though, the search is on for alternatives. These range from giant batteries, via caverns filled with compressed air, to huge flywheels made of carbon-fibre composites. But one firm looking into the matter eschews all these. It has stuck with the logic of pumped storage, which is to move large amounts of matter up and down hills. The difference is that in its case the matter is solid.
The firm in question calls itself ARES, which stands for Advanced Rail Energy Storage.
[...] The rocks stand in for the water in a pumped-storage system. They are carried up- and downhill by a train that is thus the equivalent of the turbines. The track the train runs on is equivalent to the tunnel. And the motors that drive the train act, like the electrical kit of a pumped-storage turbine, as generators when they run in reverse as the train rolls backwards downhill, pulled by gravity.
(Score: 0) by Anonymous Coward on Sunday December 04 2016, @02:26AM
I did the math once a few years ago. I wanted to store two days worth of solar generated electricity for my house. It came out to a block of concrete the size of a two-car garage being hoisted 40 feet, if I recall correctly.
I also read somewhere that a single AA battery contains enough energy to lift 800 lbs. about 10 feet (assuming a perfectly efficient lifting mechanism)
Remember, gravity is the weakest of the four fundamental forces. You can fall out of an airplane and accelerate for 10,000 feet, but a few inches of concrete being held together by electromagnetic and nuclear forces will stop you cold.
Thermal storage seems more efficient. Use a heat pump to create a cold and a hot reservoir (pebbles, salt, bricks...) then use a stirling engine to extract the energy. The biggest problem with this is insulation.
(Score: 0) by Anonymous Coward on Sunday December 04 2016, @03:21AM
Actually, you can only fall out of a plane and accelerate at any appreciable rate for about 1000 feet; then you're within spitting distance of terminal velocity.