Friday, March 17, 2017

Using an Abandoned Coal Mine for Pumped Water Energy Storage

The most common sort of energy storage in the world's power grids is pumped water. It's pretty simple: when you have excess power you pump water uphill, and when you need extra power you let it flow back down. In Germany they have hit on a scheme to do this in an old, 600-meter (2000-foot) deep coal mine. Not as much water is needed as in a traditional scheme because the vertical distance is so great, and there's no evaporation when it's under ground. This also provides a handful of jobs in a district where the decline of coal mining has hammered the local economy. Pretty clever.

1 comment:

G. Verloren said...

A quick google search tells me that water turbines easily manage 80% efficiency, and larger systems can hit 95%. That's pretty darn good in terms of getting back the energy it takes to pump the water uphill in the first place.

Using water to store excess energy in a stable state. A very elegant concept. I like it a lot.