Solar Thermal Aerogel Receiver (STAR) Project
In contrast to photovoltaic systems, where sunlight is directly converted to electricity, solar thermal systems first convert sunlight to heat and subsequently to electricity through a heat engine, e.g. a steam turbine. The main advantage in such solar thermal systems is that the intermediate heat produced can be stored more easily and at a significantly lower cost than electricity.
The NanoEngineering Group headed by Prof. Gang Chen in MIT MechE is currently developing a new type of concentrating solar thermal power (CSP) receiver that aims to significantly lower the cost of electricity compared to state of the CSP parabolic trough technology.
The new receiver concept, nicknamed the Solar Thermal Aerogel Receiver (STAR), utilizes an Optically-Transparent Thermally-Insulating (OTTI) aerogel material to effectively trap the heat generated by the absorbed solar energy. The OTTI allows high temperatures, and thus high heat engine efficiencies, to be reached by minimizing thermal losses while still allowing sunlight to be efficiently absorbed.
The STAR achieves near vacuum-level heat loss performance without the need for vacuum, thus allowing for a less expensive and more robust solar collector design. Our models indicate that STAR paired with linear Fresnel reflectors could produce electricity at 75% of the cost of state-of-the-art vacuum tube receivers paired with parabolic trough collectors. We are currently constructing an on-sun experimental proof-of-concept of the STAR system at the MIT Bates facility, with a first experimental demonstration planned for summer 2017.
This project is supported by the U.S. Department of Energy through the Advanced Research Projects Agency−Energy (ARPA-E) FOCUS program under Award No. DE-AR0000471.