Ceramic Matrix Composites for Concentrating Solar Power Receivers

Concentrating Solar Power (CSP) offers significant potential as a clean an inexhaustible utility- scale energy source to meet ever-increasing global and domestic energy demands. Most CSP power generation concepts work by the optical concentration of sunlight to heat a working fluid, from which useful electricity may be generated using a thermodynamic cycle. The central receiver CSP plant design utilizes a field of tracking mirrors to concentrate the solar radiation on a singular point, resulting in higher solar concentration ratios and higher operating temperatures than many alternative CSP designs. However, the capabilities of pressurized tubular receivers are currently limited by the temperature limitations of the metallic materials from which they are constructed. Additional materials are needed to facilitate increases in cycle operating temperatures in order to yield increases in the efficiencies of thermodynamic cycles and thermal energy storage in order to make CSP an economically viable option for power generation. Continuous fiber-reinforced ceramics are an emerging class of materials that offer considerable potential for increasing the operating temperatures of central receiver CSP plants. The incorporation of high strength, relatively high modulus ceramic fiber reinforcement within a ceramic matrix produces a material with significantly greater toughness, flaw insensitivity, and strain capability than a monolith, while maintaining high-temperature refractory capabilities. Silicon carbide fiber-reinforced silicon carbide (SiC/SiC) offers the necessary high-temperature strength and oxidation resistance, and has been identified as a suitable candidate material for the high-flux portion of the solar receiver. The proposed Phase I effort will encompass the design of a pressurized CMC tubular solar receiver; the demonstrated fabrication of receiver prototypes and material for coupon-level materials testing; and the evaluation of thermal and mechanical materials properties, as well as the structural and thermal performance of the solar receiver prototypes.