Retrofitting a Geothermal Plant with Solar and Storage to Increase Power Generation

Conference · Wed Oct 04 04:00:00 EDT 2017

OSTI ID:1433306

Zhu, Guangdong ^[1]; McTigue, Joshua Dominic P ^[1]; Turchi, Craig S ^[1]; Castro, Jose ^[2]; Mungas, Greg ^[3]; Kramer, Nick ^[3]; King, John ^[3]

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1. National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2. Coso Operating Co.
3. Hyperlight Energy

Solar hybridization using concentrating solar power (CSP) can be an effective approach to augment the power generation and power cycle efficiency of a geothermal power plant with a declining resource. Thermal storage can further increase the dispatchability of a geothermal/solar hybrid system, which is particularly valued for a national grid with high renewable penetration. In this paper, a hybrid plant design with thermal storage is proposed based on the requirements of the Coso geothermal field in China Lake, California. The objective is to increase the power production by 4 MWe. In this system, a portion of the injection brine is recirculated through a heat exchanger with the solar heat transfer fluid, before being mixed with the production well brine. In the solar heating loop the brine should be heated to at least 155 degrees C to increase the net power. The solar field and storage were sized based on solar data for China Lake. Thermal storage is used to store excess power at the high-solar-irradiation hours and generate additional power during the evenings. The solar field size, the type and capacity of thermal storage and the operating temperatures are critical factors in determining the most economic hybrid system. Further investigations are required to optimize the hybrid system and evaluate its economic feasibility.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Geothermal Technologies Office (EE-4G)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1433306
• Report Number(s): NREL/CP-5500-68620
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
concentrating solar
geothermal
hybrid plant
thermal energy storage