My 6th grade science fair project was a 250KV tesla coil. Would light a flourescent (burnt out even) bulb about 30 ft away. It was a big tuned transformer at about 100 Khz basicly. Also destroyed off air tv and radio reception over quite a range. Definately not good for computer circuitry in the near vicinity either.
As for the Tesla turbine, here are a couple of links...
http://www.teslaengine.org/main.html http://www.phoenixnavigation.com/ http://phoenixnavigation.com/ptbc/home.htm
As for using old oil wells for geothermal, you would want to drill them quite a bit deeper in most cases. California has some geothermal plants in production, but of course they are near the pacific "ring of fire" where thermal energy is available nearer the surface. One test well in austrailia back in 2003 was over 14,000 feet deep. Many older plugged wells are only 2000 ft deep. Just have to look around.
Steve