Design of a Geothermal Power Plant With Solar Thermal Topping Cycle

Conference · Wed Oct 04 04:00:00 EDT 2023

OSTI ID:2290260

McTigue, Joshua D.; Simpson, Juliet G.; Zhu, Guangdong; Neupane, Ghanashyam; Wendt, Daniel

Geothermal power plants are a reliable source of low-carbon power generation. However, modern electricity markets comprise relatively large proportions of variable renewable energy generation that may require power plants to flexibly dispatch energy. The power output, efficiency, and dispatch flexibility of a geothermal plant can be enhanced by integrating solar thermal energy into the system, as well as possibly compensating against ambient temperature variations. Concentrating solar thermal (CST) can generate temperatures much higher than conventional geothermal systems. Using a solar topping cycle is one way to efficiently convert high-temperature solar heat to electricity while also cascading lower-temperature heat to the geothermal power cycle, thereby increasing its power output and possibly its efficiency. A hybrid power cycle design is proposed and simulated using SimTech IPSEpro process modeling software. The design configuration depends on the expected temperature of the geothermal resource and the quantity of solar heat added at the design point. These design considerations are described and expected performance is calculated. The solar heat addition varies throughout the day and year; therefore, off-design models are necessary to assess the impact of solar availability (and ambient temperature) on the power plant performance. Off-design models are developed and combined with hourly weather data to facilitate an evaluation of annual system performance.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Geothermal Technologies Office
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 2290260
• Report Number(s): NREL/CP-5700-88734; MainId:89513; UUID:50211628-638a-400d-9d3d-f0377d03f366; MainAdminId:71746
• Country of Publication: United States
• Language: English

Related Subjects

GEOTHERMAL ENERGY
SOLAR ENERGY
concentrating solar power
geothermal power
hybrid power generation
thermal energy storage