High-Temperature Topping Cells from LED Materials
There are two primary methods for capturing and using sunlight today: direct conversion of sunlight to electricity using photovoltaic (PV) solar panels, or focusing sunlight onto a fluid that is used to drive a steam turbine in concentrated solar power (CSP) systems. Storing hot fluid in CSP systems is a less expensive way to generate electricity when the sun is not shining compared to storing electrical energy from PV in batteries. However, PV uses just part of the solar spectrum at high efficiency, while CSP systems use the entire solar spectrum but at low efficiency. Combining the best elements of these two technologies could provide a means to get the most out of the full solar spectrum, generating both electricity and storable heat (for later use) within the same system. Developing hybrid solar energy systems that perform both functions at the same time could provide electricity at cost comparable to traditional sources, whether the sun is shining or not.
Project Innovation + Advantages:
Arizona State University (ASU) is developing a solar cell that can maintain efficient operation at temperatures above 400°C. Like many other electronics, solar panels work best in cooler environments. As the temperature of traditional solar cells increases beyond 100°C, the energy output decreases markedly and components are more prone to failure. ASU’s technology adapts semiconducting materials used in today’s light-emitting diode (LED) industry to enable efficient, long-term high-temperature operation. These materials could allow the cells to maintain operation at much higher temperatures than today’s solar cells, so they can be integrated as the sunlight-absorbing surface of a thermal receiver in the next generation of hybrid solar collectors. The solar cell would provide electricity using a portion of the incoming sunlight, while the receiver collects usable heat at high temperature that can be stored and dispatched to generate electricity as needed.
If successful, ASU’s solar cell will extract far more energy from the highest-energy portion of the solar spectrum than today’s solar cells when used at high temperatures in the next generation of hybrid solar energy systems.
Developing new hybrid solar systems that generate both electricity and dispatchable heat at the same time could provide clean domestic power at costs comparable to traditional sources, whether the sun is shining or not.
Replacing energy systems powered by fossil fuels would provide an immediate decrease in greenhouse gas emissions, 40% of which come from electricity generation today.
Cost-effective, dispatchable solar energy alternatives would stabilize electricity rates for consumers as the penetration of renewable energy increases in the coming years.