Advanced design and economic considerations for commercial geothermal power plants at Heber and Niland, California. Final report

Technical Report · Sat Oct 01 00:00:00 EDT 1977

DOI:https://doi.org/10.2172/6807967· OSTI ID:6807967

Two separate studies, involving advanced design and economic considerations for commercial geothermal power plants using liquid-dominated hydrothermal resources, are presented. In the first study, the effects on design, capital cost, and bus bar electric energy production cost caused by an anticipated decline in available geothermal fluid temperature over the lifetime of power plants are described. A two-stage, flashed-steam energy conversion process was used for the conceptual design of the power plants, which operate from the moderate-temperature, low-salinity reservoir at Heber, California. Plants with net capacities of 50, 100, and 200 MWe (net) were investigated. The results show that it is important to include provision for geothermal fluid temperature decline in the design of power plants to prevent loss of electric energy production capability and to reduce bus bar electric energy costs. In the second study, the technical, economic, and environmental effects of adding regeneration to a 50 MWe (net) power plant employing the multistage-flash/binary process are described. Regeneration is potentially attractive because it recovers waste heat from the turbine exhaust and uses it in the power cycle. However, the pressure drop caused by the introduction of the regenerator decreases the turbine expansion and thus decreases system performance. An innovative approach was taken in the design of the regenerator, which minimized the expected performance degradation of the turbine. The result was that the performance, capital cost, and bus bar electric energy production cost are nearly the same for the processes with and without regeneration. On the other hand, the addition of regeneration has the environmental benefits of substantially reducing heat rejection to the atmosphere and cooling tower makeup and blowdown water requirements. It also increases the temperature of the brine returned to the field for reinjection.

• Research Organization: Bechtel Corp., San Francisco, Calif. (USA)
• DOE Contract Number: EY-76-C-03-1124
• OSTI ID: 6807967
• Report Number(s): SAN-1124-2
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
GEOTHERMAL POWER PLANTS
DESIGN
ECONOMIC ANALYSIS
WASTE HEAT UTILIZATION
HEBER GEOTHERMAL FIELD
SALTON SEA GEOTHERMAL FIELD
BINARY-FLUID SYSTEMS
CAPITAL
ECONOMIC DEVELOPMENT
ELECTRIC POWER
ENVIRONMENTAL IMPACTS
FEASIBILITY STUDIES
FLASHED STEAM SYSTEMS
FLUID FLOW
GEOTHERMAL FLUIDS
MATHEMATICAL MODELS
POWER GENERATION
REGENERATION
REINJECTION
TEMPERATURE DEPENDENCE
ECONOMICS
FLUIDS
GEOTHERMAL FIELDS
POWER
POWER PLANTS
THERMAL POWER PLANTS
WASTE PRODUCT UTILIZATION
Geothermal Legacy
150801* - Geothermal Power Plants- Design & Operation
150500 - Geothermal Energy- Economics
Industrial
& Business Aspects