Power plant components and systems for concentrating solar power (CSP) benefit from a mature and well-understood technology found elsewhere in the power generation industry. The most common cycles employed by conventional CSP plants include subcritical Rankine and Stirling. Gross thermal-to-electric conversion efficiencies are typically 35%–45%. Working fluids include steam, hydrogen, and helium.
The primary driver for improving the power cycles is increasing conversion efficiency. Because CSP facilities are typically located in desert areas where water is a scarce resource, high-efficiency cycles utilizing dry cooling are needed, which may include systems that use topping and bottoming cycles, augmentation, or other hybrid options.
The SunShot Initiative funds research and development (R&D) on power block and related aspects within the industry, national laboratories and universities to achieve the following technical targets of power block subsystems:
- High temperature power cycles
- Net cycle efficiency > 50%
- Dry cooled
- Cost < 1,200/kWe
The R&D approaches toward these goals are broadly in the areas of:
- developing high temperature power cycles, such as supercritical-CO2 and solar integration to Brayton cycles
- developing solid state power conversion techniques as topping cycles
- investigating hybrid power systems