I always thought any generated energy can be stored only in batteries.
The most efficient energy storage technology may be as close as the nearest hill, according to former Energy Secretary Steven Chu, and almost as old.
“It turns out the most efficient energy storage is you take that electricity and you pump water up a hill,” Chu said Tuesday at the Stanford University Global Energy Forum.
When electricity is needed, you let the water flow down, spinning generators along the way. Pumped hydro can meet demand for seasonal storage instead of the four hours typical of lithium-ion batteries.
Steven Chu: Long-Term Energy Storage Solution Has Been Here All Along
So, you can have a hydro power plant generate electricity with water flowing down and use any excess electricity to pump water back up the reservoir to store the excess energy. Neat!