A binary cycle power plant is a type of geothermal power plant that allows cooler geothermal reservoirs to be use than with dry steam and flash steam plants. They are used when the temperature of the water is less than 175 °C (350 °F). With binary cycle geothermal power plants, pumps are used to pump hot water from a geothermal well, through a heat exchanger, and the cooled water is returned to the underground reservoir. A second "working" or "binary" fluid with a low boiling point, typically a butane or pentane hydrocarbon, is pumped at fairly high pressure (500 PSI) through the heat exchanger, where it is vaporized and then directed through a turbine. The vapor exiting the turbine is then condensed by cold air radiators or cold water and cycled back through the heat exchanger. Examples of binary cycle geothermal plants can be found at Mammoth Lakes, California, Steamboat Springs, Nevada and Hilo, Hawaii.