How can you store hydroelectric energy?

Question

In what ways and it would help if you could give me either a website or something else that i could go to for info on hydroelectric energy

Answer 1

Pump the water back up to the top of the dam and put it back in the lake behind the dam. They actually do this in some cases I understand. At times when power demand is low they use the extra power to pump water from below the dam back up into the lake behind the dam so that later, when power demand is high they can let it flow through the generators to make more electricity. This only makes sense if they completely shut down the hydroelectric generators and use other power sources to do the pumping. It would be silly to just run water through the hydroelectric generators just so they could use the power to pump the water back. It would be better to just shut everything off and let the water wait on the high side for demand to increase.

Now don't go getting perpetual motion machine ideas. You can't get free electricity by just using part of the electricity generated to pump all the water back up. It takes more electricity to pump the water back up than that same water can generate flowing through the generators, because the generators are less than 100% efficient. But as a way to store energy, it is as efficient as charging up a bunch of giant batteries and way cheaper.

Answer 2

With a dam.