|reply to lugnut |
Re: GravityLight: lighting for developing countries.
Both the U.S. and Canadian hydroelectric installations in Niagara Falls use reservoir energy storage. Fill at night with water from above the falls, drain during high demand (day) through the generators and it exits below the falls.
As for the general usefulness of reservoir storage, they take up a LOT of space per KWH stored, plus the turnaround efficiency isn't all that great. Plopping a big storage lake in the middle of an area creates its own eco-issues and likely displaces a bunch of people, may require a massive public works project to contour the land properly, etc.