Page 112 - Managing Global Warming

82 Managing Global Warming

Fig. 3.16 (A) Aerial view showing portions of Solar Energy Generating Systems (SEGS) (CA,
United States). SEGS is one of the largest solar energy power plants in the world. SEGS consist
of 9 concentrated-solar-thermal plants with 354-MW el installed capacity. The average gross
solar output of SEGS is about 75MW el (capacity factor is 21%). At night, turbines can be
powered by combustion of natural gas. NextEra claims that the SEGS power 232,500 homes and
decrease pollution by 3800t per year (if the electricity had been provided by combustion of oil).
2
The SEGS have 936,384 mirrors, which cover more than 6.5km . If the parabolic mirrors
would be lined up, they will extend over 370km. In 2002, one of the 30-MW el Kramer Junction
sites required 90 million dollars to construct, and its O&M costs are about 3 million dollars
per year, which are 4.6¢ per kWh. However, with considered lifetime of 20years, the O&M
and investments interest and depreciation triples the price to 14¢ per kWh [13]. (B) General
schematic of a typical concentrated solar power plant (CSPP): (1) SENERtrough collectors;
(2) steam-generator system: (3) steam turbine with electrical generator; (4) electrical
transformer; (5) condenser; (6) cooling towers; (7) heat exchanger; (8) thermal storage system;
and (9) heat transfer fluid (HTF) boiler.
(A) Wikimedia Commons: photo by A. Radecki; (B) Based on Valle 1 and 2 CSPP built in the
province of Cadiz, Spain by SENER/TORRESOL ENERGY (courtesy of SENER/TORRESOL
ENERGY).