The U.S. Department of Energy (DOE) launched the SunShot Initiative in 2011 with the goal of making solar electricity cost-competitive with power from conventional generation technologies by 2020. Included in the SunShot Initiative are cost and performance targets for solar photovoltaic (PV) and concentrating solar power (CSP) systems. Unlike PV systems, CSP technology captures and stores the sun’s energy in the form of heat, using materials that are low cost and materially stable for decades. This allows CSP with thermal energy storage (TES) to deliver renewable energy while providing important capacity, reliability and stability attributes to the grid, thereby enabling increased penetration of variable renewable electricity technologies.

Today’s most advanced CSP systems are towers integrated with 2-tank, molten-salt TES, delivering thermal energy at 565°C for integration with conventional steam-Rankine power cycles. These power towers trace their lineage to the 10-MWe pilot demonstration of Solar Two in the 1990s. This design has lowered the cost of CSP electricity by approximately 50% over the prior generation of parabolic trough systems; however, the decrease in cost of CSP technologies has not kept pace with the falling cost of PV systems.

Since the 2011 introduction of SunShot, DOE’s CSP Subprogram has funded research in solar collector field, receiver, TES, and power cycle sub-systems to improve the performance and lower the cost of CSP systems. In August of 2016, DOE hosted a workshop of CSP stakeholders that defined three potential pathways for the next generation CSP plant (CSP Gen3) based on the form of the thermal carrier in the receiver: molten salt, particle, or gaseous. Prior analysis by DOE had selected the supercritical carbon dioxide (sCO2) Brayton cycle as the best-fit power cycle for increasing CSP system thermo-electric conversion efficiency. The research is designed to enable a CSP system that offers the potential to achieve the overall CSP SunShot goals—yet no one approach exists without at least one significant technical, economic, or reliability risk.

This roadmap addresses and prioritizes research and development (R&D) gaps and lays out the pathway for a “Gen3 CSP Roadmap.” Throughout the roadmap process, the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (Sandia) engaged appropriate stakeholders, including the CSP industry and developers, utilities, and the laboratory and university research and development (R&D) community. An industry-led Technical Review Committee (TRC) was established to guide the roadmap activity. Technology gaps for each of the technology pathways were identified, together with research priorities designed to address them. This information will be used by DOE to inform and prioritize R&D activities leading to one or more technology pathways to be successfully demonstrated at a scale appropriate for future commercialization of the technology.

Location Golden, CO
Date January 2017
Topic Financing, Incentives & Market Analysis
Subprogram Concentrating Solar Power
Author National Renewable Energy Laboratory