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'No-water' hydropower turns England's hills into green and pleasant batteries
(www.rechargenews.com)
That's a pretty interesting idea. Using a fluid much denser than water to turn turbines. My main concern would be what their "patented fluid" is and how much damage would be done if it leaks. EDIT: Had a look at their site and the "high tech" fluid is made of commonly available materials and is non-toxic, non-reactive and environmentally benign. Flour and water? Slime?