wHAT IS CSP?
Concentrated solar power (CSP) uses mirrors to concentrate the sun’s heat onto a receiver and convert solar thermal energy for either, driving traditional steam turbines or engines that produce electricity, or using directly the heat for industrial processes.
CSP specifically can be integrated with thermal storage for later conversion to electricity or in hybrid operation with other technologies, offering firm capacity and dispatchable power on demand. It is suitable for peak loads and base-loads and power is typically fed into the electricity grid.
WHAT IS SUPERCRITICAL CO2?
Supercritical carbon dioxide (CO2) is a fluid state of CO2 where it is heated and held at or above its critical temperature and pressure. In this supercritical phase, CO2 exhibits properties and behaviours between that of a liquid and a gas. In particular, supercritical CO2 possesses liquid-like densities with gas-like diffusivity, surface tension and viscosity.
When CO2 exceeds temperatures of 87.9°F (31.1°C) and is subjected to pressures above 1071 psi (7.39 MPa), it enters the supercritical phase. This phase of CO2 is commonly used as a solvent in chemical extraction processes due to its high solubility, low toxicity and minimal net effect on the environment.
Supercritical CO2 cycles can be configured to accommodate the temperature and pressure characteristics of various heat sources (including renewables like solar), providing superior efficiency in converting heat to electrical power. Carbon dioxide is particularly attractive as a working fluid because of its low toxicity and, in the supercritical region, its compressibility and ability to transfer heat.