Geothermal Power Plant (PLTPB)

Geothermal energy, heat energy is stored in the rock below the land surface and the fluid contained therein. Geothermal energy has been used for power generation in Italy since 1913 and in New Zealand since 1958. Use of geothermal energy for non-electric sector (direct use) occurred in Iceland about 70 years. The growing demand for energy and oil prices, especially in 1973 and 1979, have spurred other countries, including the United States to reduce its dependence on oil by harnessing geothermal energy. Currently, geothermal energy has been harnessed for power generation in 24 countries, including Indonesia.
Besides the geothermal fluid is also used for non-electricity sector in 72 countries, among others, for space heating, water heating, greenhouse heating, drying of agricultural products, soil heating, drying wood, paper etc. .

Geothermal system in Indonesia is often a hydrothermal system having a high temperature (> 225 ° C), only some of which have a moderate temperature (225 ° C-150). Experience of geothermal fields were developed in world and Indonesia showed that the high temperature geothermal systems and are potentially searched for when power generation. The potential of geothermal resources Indonesia is very large, which is about 27,500 MW, about 30-40% of the geothermal potential in the world.

Geothermal power plant (PLTP) in principle the same as Steam Power Plant (CPP), just steam plant is on the surface using a boiler, while the steam from geothermal power plants geothermal reservoir. If the fluid at the wellhead in the form of a vapor phase, the vapor may be passed directly to the turbine, and then the turbine will convert geothermal energy of motion which will turn a generator to produce energy Electric.

If the geothermal fluid out of the head as well as the mixture of fluids in two phases (the vapor phase and liquid phase), the first held in the separation process fluid. This is possible through the passage of fluid into the separator, so that the vapor phase is separated from the liquid phase. The vapor fraction resulting from the separation is then channeled to the turbine.

If the geothermal resource has moderate temperatures, the geothermal fluid can still be used to generate electricity using binary cycle power plant (plant binary). In this power cycle, the secondary fluid ((isopentane isobutane, or ammonia) is heated by geothermal fluid through the heat exchanger of the engine or heat exchanger.

Secondary fluid vaporizes at a temperature below the boiling point of water at the same pressure. The flow of fluid to the secondary turbine and then condensed before being used again heated by geothermal fluid. Closed loop, wherein the geothermal fluid is not taken their time but only the heat is extracted by a second fluid, while the geothermal fluid is injected back into the reservoir.

There are still some energy generation system of geothermal fluid that have been applied in the field, them : Single Flash Steam, Double Flash Steam, Multi Flash Steam, , Combined Cycle, Hybrid/fossil–geothermal conversion system.