Performance evaluation of a 12.8-MW single-flash design geothermal power plant in Northern Nevada is conducted using actual plant operating data, and potential improvement sites are identified. The unused geothermal brine reinjected back to the ground is determined to represent about 50 percent of the energy and 40 percent of the exergy available in the reservoir. The first and second-law efficiencies of the plant are determined to be 6 percent and 22 percent, respectively. Optimizing the existing single-flash system is shown to increase the net power output by up to 4 percent. Some well-known geothermal power generation technologies including double-flash, binary, and combined flash/binary designs as alternative to the existing system are evaluated and their optimum operating conditions are determined. It is found that a double-flash design, a binary design, and a combined flash/binary design can increase the net power output by up to 31 percent, 35 percent, and 54 percent, respectively, at optimum operating conditions. An economic comparison of these designs appears to favor the combined flash/binary design, followed by the double-flash design.

Issue Section:
Technical Papers
Topics:
Geothermal power stations, Design, Exergy, Geothermal engineering, Geothermal power, Performance evaluation, Reservoirs
1.
Allegrini, G., and Barbier, E., 1993, The Geothermoelectric Generation in Italy: Planning Strategies, Experience Gained During Operation, and Cost Analysis, VDI Berichte 1024. VDI Verlag, Munich, Germany, pp. 123–139.
2.
Barbier
E.
,
1997
, “
Nature and Technology of Geothermal Energy: A Review
,”
Renewable & Sustainable Energy Reviews—An International Journal
, Vol.
1
, No.
1/2
, pp.
1
–
69
.
3.
DiPippo, R. A., 1994, “Second Law Analysis of Flash-Binary and Multilevel Binary Geothermal Power Plants,” Geothermal Resources Council Transactions, Vol. 18.
4.
Gould, W. R., 1993, “Edison’s QF Experience,” Proceedings Geothermal Energy—The Environmentally Responsible Energy Technology for the Nineties, Geothermal Program Review XI, U.S. Department of Energy, CONF/-930484.
5.
Hudson, R. B., 1995, “Electricity Generation,” Geothermal Energy, eds., M. H. Dickson and M. Fanelli, John Wiley & Sons, Chichester.
6.
Kanog˘lu
M.
,
C¸engel
Y. A.
, and
Turner
R. H.
,
1998
, “
Incorporating a District Heating/Cooling System to an Existing Geothermal Power Plant
,”
ASME JOURNAL OF ENERGY RESOURCES TECHNOLOGY
, Vol.
120
, June, pp.
179
–
184
.
7.
Klein, S. A., and Alvarado, F. L., 1997, EES—Engineering Equation Solver, Version 4.481, F-Chart Software, 4406 Fox Bluff Rd. Middleton, WI.
8.
Michaelides
E. E.
, and
Ryder
J. K.
,
1992
, “
The Influence of Seasonal and Daily Temperature Fluctuations on the Work Produced by Geothermal Power Plants
,”
International Journal of Energy Systems
, Vol.
12
, No.
2
, pp.
68
–
72
.
9.
Milora, S. L., and Tester, J. F., 1976, Geothermal Energy as a Source of Electric Power, Thermodynamic and Economic Design Criteria, The MIT Press, Cambridge, MA.
10.
Paloso
G.
, and
Mohanty
B.
,
1993
, “
A Flashing Binary Combined Cycle for Geothermal Power Generation
,”
Energy—The International Journal
, Vol.
18
, No.
8
, pp.
803
–
814
.
11.
Phair
K. A.
,
1994
, “
Getting the Most out of Geothermal Energy
,”
ASME Mechanical Engineering
, Vol.
116
, pp.
76
–
80
.
12.
Subbiah
S.
, and
Natarajen
R.
,
1988
, “
Thermodynamic Analysis of Binary-Fluid Rankine Cycles for Geothermal Power Plants
,”
Energy Conv. & Management
, Vol.
28
, No.
1
, pp.
47
–
52
.
13.
Yuan
Z.
, and
Michaelides
E. E.
,
1993
, “
Binary-Flashing Geothermal Power Plants
,”
ASME JOURNAL OF ENERGY RESOURCES TECHNOLOGY
, Vol.
115
, pp.
232
–
236
.
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