(5) Power from not-so-hot Geothermal
Geothermal power normally derived from sources higher then 300ºF , which are deep underground.
United Technologies Research Center in east Hartford, CT has developed a low-cost system to utilize low-temperature geothermal source.
The modular 200 KW pilot plant has following features:
Can convert temperatures as low as 165ºF to electricity.
Similar to steam engines.
Hot water vaporizes a Hydroflurocarbon refrigerant, which drives a turbine.
Refrigerant has lower boiling point than water.
New turbine is essentially a refrigerator compressor running backwards.
Can be used to capture power from hot formation water produced in oil fields.
Texas alone produces 12 Billion bbls of hot water, which is discarded by re-injection.
Demonstration plants are planned in Texas and Nevada to try out . The power generated can be used in the oil fields to run pumps for the producing wells.