What are Solar Collectors?

In concentrating solar-thermal power (CSP) plants, collectors reflect and concentrate sunlight and redirect it to a receiver, where it is converted to heat and then used to generate electricity. In tower (or central receiver) plants, mirrors, known as heliostats, track the sun on two axes, with each heliostat typically on its own base, foundation, and motor to direct sunlight onto the receiver at the top of a tower. In parabolic trough plants, mirrors line the inside of a trough-shaped array, which follows the sun in only one direction, and concentrates the light on a linear receiver pipe. Learn more about how CSP works.

Why are Solar Collectors Important?

Collectors are the starting point for the conversion of sunlight into energy. They must be designed to efficiently concentrate light while minimizing fabrication, installation, and operating costs. Collectors that can cost-effectively achieve high concentrations of sunlight are able to directly improve the efficiency of the receiver. Currently, collectors can comprise 25 percent or more of the total system capital costs for CSP plants. The U.S. Department of Energy Solar Energy Technologies Office (SETO) is working to lower collector costs, with a target of $50 per square meter for highly autonomous heliostats, to reach its goal of $0.05 per kilowatt-hour for baseload CSP plants with at least 12 hours of thermal energy storage. Learn more about SETO’s CSP goals.

SETO Research in Solar Collectors

SETO funds research and development in this area to improve the performance and lower the cost of solar collectors and produce prototypes that demonstrate the viability of advanced technologies for future integration in CSP plants. In particular, SETO-funded projects are working to develop solutions that enable a solar collector field to fully operate without any human input, reducing operating costs and maximizing thermal energy collection efficiency. Several of SETO’s funding programs have projects that focus on solar collectors:

• HelioCon—the Heliostat Consortium for Concentrating Solar-Thermal Power – supporting research, development, validation, commercialization, and deployment of low-cost and high-performance heliostats with optimized operations and maintenance for CSP applications
• American-Made Heliostat Prize – accelerating technology innovation through the design, development, and demonstration of key components of heliostats
• Solar Energy Technologies Office Fiscal Year 2019 funding program – automating CSP collector fields that can operate without human input
• Concentrating Solar Power: Concentrating Optics for Lower Levelized Energy Costs funding program – producing dramatic improvements and cost reductions in collectors through design and manufacturing
• Concentrating Solar Power: Advanced Projects Offering Low LCOE Opportunities funding program – developing transformative solutions to break through collector performance barriers

To view specific solar collector projects, search the Solar Energy Research Database.

Additional Resources

• National Renewable Energy Laboratory: Concentrating Solar Power Best Practices Study

Learn more about CSP research, other solar energy research in SETO, and current and former SETO funding programs.