Radiative cooling and cold storage for concentrated solar power plants

Abstract

Concentrated solar power (CSP) plants are generally located in solar-abundant yet hot and water-stressed locations. In such circumstances, efficient but water-intensive once-through wet cooling and water-free but inefficient air cooling are both unfavorable. Considering both thermal efficiency and water availability/temperature, recirculating evaporative cooling is a better alternative. However, evaporative cooling still loses large amounts of water into the atmosphere and thus requires a nonstop water supply. Therefore, simultaneously reducing water loss and maintaining thermal efficiency requires efficient means of supplemental cooling for CSP plants. Following our previous work on scalable radiative cooling films and a kW-scale radiative cooling system, we explore the potential of consumptive water use reduction in recirculating wet-cooled CSP plants by integrating supplemental radiative cooling and cold storage. Through modeling of a reference CSP plant with a supplemental radiative cooling system as large as the plant solar field, the results show that 40%–60% of the annual consumptive water use can be potentially reduced in the hot southwestern U.S. region with daytime-only radiative cooling, whereas the annual potential water saving can be as much as 65%–85% if the radiative cooling system works both day and night with cold storage.

Keywords

• Radiative cooling
• Power plant cooling
• Concentrated solar power
• Water saving