National Renewable Energy Laboratory

Concentrating Solar Power Research

Parabolic Trough Thermal Energy Storage Technology

NREL works to develop efficient and lower cost thermal energy storage technologies for parabolic trough concentrating solar power systems. Improved thermal energy storage is needed to:

• Increase solar plant capacity factors above 25%
• Increase dispatchability of solar power
• Help reduce the cost of solar electricity.

Parabolic trough technology currently has one thermal energy storage option—a two-tank, indirect, molten-salt system. The system uses different heat transfer fluids for the solar field and for storage. Therefore, it requires a heat exchanger. It has a unit cost of $30-$40/kWht.

To reduce the unit cost to below $10/kWht, we're working to develop single-tank, thermocline storage systems and heat transfer fluids that can be used in both the solar field and in the storage system.

See information on NREL's Advanced Thermal Storage Materials Laboratory to learn more about our capabilities concerning the research and development of heat transfer fluids.

Visit TroughNet for an overview of parabolic trough thermal energy storage technology.