Generation 3 Concentrating Solar Power Systems

NREL is defining the next generation of concentrating solar power (CSP) plants through integration of thermal energy storage technologies that enhance system capacity, reliability, efficiency, and grid stability.

NREL performs research to support the U.S. Department of Energy Solar Energy Technologies Office's Generation 3 Concentrating Solar Power Systems (Gen3 CSP) initiative. The goal of this initiative is to advance solar collector field, receiver, thermal energy storage, and power cycle subsystems to improve performance and achieve ambitious targets for the cost-effectiveness of CSP systems. A central goal of the Gen3 CSP initiative is to lower the cost of CSP systems to approximately $0.05 per kilowatt-hour to help make solar baseload configurations cost competitive with other dispatchable power generators throughout the sunny, southern half of the United States.

Constructing the Roadmap for Generation 3 Concentrating Solar Power Research

Today's most advanced CSP plants are power towers integrated with two-tank, molten-salt thermal energy storage. These systems deliver thermal energy at 565°C for integration with conventional steam-Rankine power cycles. Key to decreasing system costs and fulfilling Gen3 CSP goals is increasing plant efficiency by raising the temperature of the heat delivered to the power cycle to over 700°C.

NREL supported the Department of Energy by developing a CSP Gen3 Demonstration Roadmap that identified three potential pathways to raise temperatures to over 700°C, based on the form of the thermal carrier in the receiver: molten salts (the "molten-salt" pathway), gas-phase heat-transfer fluids such as carbon dioxide or air (the "gas-phase" pathway), or falling curtains of tiny solid particles  (the "particle" pathway).

Technology Research in Support of Generation 3 Concentrating Solar Power

NREL performs research on several topics in advancement of Gen3 CSP objectives:

• Advanced CSP system components, including receiver design, thermal storage, solar field optics and optimization, and power cycle design
• Corrosion control and materials compatibility for molten salts
• Plant dispatch optimization
• Internal insulation systems for molten salt tanks
• Drone-based inspection and calibration of power tower solar fields
• Efficient, low-cost solar fields for power towers.

For more information about NREL's Gen3 CSP research, contact Craig Turchi.