| Abstract |
The Heber Known Geothermal Resource Area in the State of California, USA, was explored and initially developed to theoretically support up to 500 MW of electrical power generation from 182░C geothermal fluids. By 1985, two power plant projects were sharing the resource: the 47-MW (net) double-flash HGC Plant owned by the Heber Geothermal Company, and the Heber Binary Plant (HBP) owned by SDG&E, designed to produce 70 MW gross, with 45 MW net capacity. The HBP plant went on line in 1985, with lower fluid temperature and a lower sustained flow rate. As a result, the plant generated only 16.5 MW gross and 5 MW net. Operation was discontinued in 1987. In 1992, SIGC contracted for a binary power plant, rated at 33 MW net output from 166oC geothermal fluid. An ORMAT modular binary power plant incorporating 6 modular power units, designed to generate 48 MW total gross power, was installed utilizing the resource previously dedicated to the decommissioned SDG&E Binary Plant. The well field was developed to minimize potential interference between the HGC double flash plant and the SIGC/ORMAT binary plant. In July 2, 1993, the SIGC/ORMAT binary plant, after an accelerated 6-month construction schedule, went on line producing 113% of its rated net output. |