From American Antigravity...
Hayes claims 55% conversion efficiency; highest in its class
"Former Rockwell Engineer Jeff Hayes proposes that Tesla Turbines can be used to tap geothermal energy from underground salt-brine in locations all over the world. Hayes is part of the International Tesla Turbine Builders Society, and well-versed in the potential of this often-overlooked but commercially viable technology.
Hayes comments that the Salton Sea in California contains enough geothermal energy locked in salt-brine to meet the entire electrical needs of the United States 20 times over, if only it could be harnessed electrically. That requires spinning a turbine, and only the Tesla Turbine is durable enough to undertake this challenge. Hayes focus is on the engineering challenges involved with making Tesla Turbines a practical tool, as well as the unique characteristics of this technology that allow it to outperform conventional bladed turbines."