On Jun 14, 2007, at 10:11 AM, <michael.dillon@bt.com> <michael.dillon@bt.com> wrote
And what about all those diesel generators? How many of them are capable of running on vegetable oil rather than diesel oil? I regularly walk past a building in London that reeks because of the diesel fuel tanks in the basement. You have to wonder about the safety of storing large amounts of petroleum oil in the centers of major cities when vegetable oil is safer, and more carbon-friendly.
Vegetable oil can degrade much faster than diesel. What you really want is a large pond at the top of a hill, and another large pond at the bottom of the same hill. When utility prices are low, pump the water to the upper pond. When power is needed, have your installed hydropower setup allow water to flow through the turbine from the upper pond to the lower pond. In a city, a very large tank located at the top of the building and an equally large one in the bottom with a pipe between the two, should suffice. Remember that the "head" or height difference is a large factor in determining how much power a hydro setup can generate. Patrick Giagnocavo patrick@zill.net