Getting to Know Geothermal Power Generation Technology

 

In this article, several geothermal-based geothermal technologies will be described. The generators used to convert geothermal fluids into electric power generally have the same components as other non-geothermal power plants, which consist of a generator, a turbine as a generator drive, a heat exchanger, a chiller, a pump, and so on.

Currently, there are three types of geothermal power plants that can convert geothermal energy into electricity, namely dry steam, flash steam, and binary cycle. These three types of technology are basically used in different conditions.

1. Dry Steam Power Plants This type of generator was the first to exist. In this type, hot steam (steam) is directed directly to the turbine and activates the generator to work to produce electricity. The remaining heat coming from the production well is returned to the reservoir through the injection well. This oldest type of generator was first used in Lardarello, Italy, in 1904 where it is still functioning well. In the United States, dry steam power is still used, such as the one in Geysers, Northern California.
2. Flash Steam Power Plants Geothermal in the form of fluids such as hot springs above 1750 C can be used as a source for generating Flash Steam Power Plants. The hot fluid is flowed into the flash tank which has a lower pressure so that hot steam occurs quickly. Hot steam called flash is what drives a turbine to activate a generator which then produces electricity. The rest of the unused heat goes back into the reservoir through the injection well. An example of Flash Steam Power Plants is the Cal-Energy Navy I flash geothermal power plant in Coso Geothermal field, California, USA.
3. Binary Cycle Power Plants (BCPP) BCPP uses a different technology from the two previous technologies, namely dry steam and flash steam. In BCPP hot water or steam from production wells never touches the turbine. Geothermal water is used to heat the so-called working fluid in the heat exchanger. The working fluid then becomes hot and produces steam in the form of flash. The steam generated in the heat exchanger is then flowed to rotate the turbine and then drive a generator to produce an electric power source. The hot steam generated in the heat exchanger is referred to as the secondary (binary) fluid. Binary Cycle Power Plants is actually a closed system. So nothing is released into the atmosphere. The advantage of BCPP is that it can be operated at low temperatures, namely 90-1750C. An example of the application of this type of BCPP technology is at the Mammoth Pacific Binary Geo-thermal Power Plants in the Casa Diablo geothermal field, USA. It is estimated that BCPP geothermal power plants will be more widely used in the future.