Geysers Performance Update Through 2002

Abstract

ís major focus at The Geysers is to extend its life and increase its output by improving plant efficiency, developing untapped reserves and extracting additional heat energy through water injection. These efforts have been successful. From 1998 to 2002, the average power plant efficiency has improved by approximately 5%. Seven wells have been brought on-line to provide an additional 450 klbm/hr of steam since 2001. The Southeast Geysers Effluent Pipeline project continues to provide benefits to Calpine by supplying 3600 gpm of secondary treated and lake water for injection since 1997. At year-end 2002, Calpineís seventeen power plants generated approximately 730 mw net from a steam supply of approximately 13,650 klbm/hr from 23 contiguous wellfields through 353 production wells.

Using the production data from 1988 through 2002, the steam decline rate for Sonoma County wellfields supplying steam to Units 5, 6, 7, 8, 9, 10, 11, 12, 14, 17, 18 and 20 (226 steam wells producing from 16 contiguous wellfields) is calculated and compared with earlier forecasts. A new decline rate for Calpine market units (292 wells producing steam from 19 contiguous wellfields) that includes above 12 power plants and Units 13, 16 and Sonoma (former SMUDGEO#1) is calculated using the data from January 1995 through December 2002. The activities related to improvements in the wellfield, water injection and power plants are also discussed. California Power Agency) operate The Geysers field that has a current installed capacity of 1541 mw net. Calpine owns and operates 17 power plants with an installed capacity of 1302 mw net. The remaining 239-mw capacity comes from two power plants owned and operated by NCPA. Calpine sells electricity to PG&E under Qualifying Facility (QF) contracts from four plants. The remaining 13 plants are referred to as ìmarket unitsî as the power generated by them is sold to the California Independent System Operator (ISO).