Battery from Water
I guess this is another form of pumped storage? Energy from flowing water. Bear in mind that it takes energy to pump up the water in the first place so it can then flow down.
It's a "Kelvin water drop electrostatic generator"! I'd build one on St. Croix, but a low-humidity environment is needed.
On a different, but science-related note, would anyone on St. Thomas be interested in sending and/or receiving light signals? I live on the north shore of St. Croix, (100 feet up) and we should be able to see each other on a clear night. It's only 36 miles after all. PM me. Thank you, -Brian