Monday, June 12, 2017

That's one weird battery

Via the New York Times, a variety of different energy storage devices, most of which I had heard of, and then one that I had not (article by Diane Cardwell and Andrew Roberts):
Back in the 1970s, a German utility wanted to build a flexible storage plant that could respond to sudden peaks in electricity demand, since its conventional plants — mainly coal — weren’t designed to dial up or down quickly. 
It didn’t have the hilly terrain needed for a hydroelectric plant, which can start operating much more quickly when demand surges. But here’s what it did have: ancient, underground salt deposits. 
Borrowing a technique commonly used to store natural gas and oil deep underground, it piped water into the salt beds to dissolve the salt and create two caverns roughly a half-mile below the grassy fields in Huntorf. The plant, which opened in 1978, uses electricity from the grid, when it’s cheap because demand is low, to compress and store air in the salt caves. 
Then, when electricity demand surges, a motor pushes the air to the surface and into a combustion system, where it burns natural gas that spins a turbine to produce electricity. Compressing the air allows it to deliver more oxygen to the turbines, making them more efficient. 
A similar plant opened in 1991 in McIntosh, Ala. Several energy companies, mainly in the United States and Europe, are exploring mining their salt deposits for storage as well.
The article has a bunch of different examples, including the classic "fill a reservoir with water, let 'er rip when you need it" one. (I really like the flywheel one - that's pretty cool.)

I don't think anyone thinks these could be practical solutions across the board, but they are pretty fun. 


  1. The Welsh hydro plant was famous when I was growing up. The article doesn't explain it very well (IMO) but I think it is pretty genius. Use off peak power surplus to pump water uphill so that at peak time you can generate power from letting it run back down again. Nifty!

    The Las Vegas molten salt solar plant is something else. You can see that thing from the air I swear a hundred miles away. I often see it when flying out of SAN even if I'm not heading to Las Vegas. Has a few problems with attracting migrating birds and then frying them.

    I'm becoming a big fan though of the 'lots of little, local' strategy. My dream is that California puts solar down the middle of all the freeways, on top of all government buildings, roofs of parking lots. Which then means lots of local batteries.

  2. the most bizarre one I heard of was a airtight cavern (e.g. after underground nuclear explosion) partly filled with water, into which a small clean thermonuclear charge would be lowered and detonated, the nearby turbines would work on the generated steam. The concept was seriously studied but it turned out even clean nukes were not clean enough

    1. Seems like something Walt Disney would have put in "Our Friend the Atom".