Page 311 - Handbook of Energy Engineering Calculations

FIGURE 2 Firing modes are shown for typical summer day, left,

typical winter day, right. Correlation of solar generation to peaking
power requirements is evident. (Luz International Ltd. and Power.)

As shown in the cycle diagram, the balance-of-plant equipment consists of
the turbine-generator, steam generator, solar superheater, two-cell cooling

tower, and an intertie with the local utility company, Southern California
Edison Co. The Mojave Desert installation represents some 90 percent of the
world’s solar power production. Since installing its first solar electric
generating system in 1984, a 13.8-MW facility, Luz has built six more SEGS
of 30 MW each. Units 6 and 7 use third-generation mirror technology.

5. Determine the costs of solar power
SEGS are suited to utility peaking service because they provide up to 80
percent of their output during those hours of a utility’s greatest demand, with
minimal production during low-demand hours.

Cost of Luz’s solar-generated power is less than that of many nuclear
plants—$0.08/kWh, down from $0.24/kWh for the first SEGS, according to
company officials. Should the price of oil go up beyond $90/barrel, solar will
become even more competitive with conventional power.

But the advantages over conventional power sources include more than
cost-competitiveness. Emissions levels are much lower—10 ppm—because
the sun is essentially nonpolluting. SEGS are equipped with the best available
technology for emissions cleanup during the hours they burn natural gas, the

only time they produce emission.