ASU engineers Stephen Goodnick and Zachary Holman will lead two multi-university/industry research teams in support of a new U.S. Department of Energy program to develop technologies that use the full spectrum of sunlight to produce inexpensive power during both day and night.
Two solar projects lead by Arizona State University engineers will receive up to $6.5 million from the U.S. Department of Energy.
Both projects aim to lower costs at the same time as increase solar power’s efficiency.
The projects are part of the Full-Spectrum Optimized Conversion and Utilization of Sunlight (FOCUS) program, aimed at developing new hybrid solar energy converters and hybrid energy storage systems that deliver low-cost, high-efficiency solar energy on-demand.
The department's Advanced Research Projects Agency – Energy (ARPA-E) recently announced allocation of $30 million in funding for 12 projects selected to conduct research for its Full-Spectrum Optimized Conversion and Utilization of Sunlight (FOCUS) program.
Stephen Goodnick will lead the project High-Temperature Indium Gallium Nitride Topping Cells, which has been allocated $3.9 million.
Goodnick is a professor in the School of Electrical, Computer and Energy Engineering, one of ASU’s Ira A. Fulton Schools of Engineering, and deputy director of ASU LightWorks, a strategic framework for light-inspired research.
Zachary Holman will lead the project Solar Concentrating Photovoltaic Mirrors, which has been allotted $2.6 million.
Holman is an assistant professor in the School of Electrical, Computer and Energy Engineering.
ARPA-E selects energy technology development projects based on their potential to enhance the nation’s economic and energy security. The projects promise to help reduce imports of energy from foreign sources, reduce energy-related emissions – including greenhouse gases – improve energy efficiency in all economic sectors and ensure the United States maintains a technological lead in developing and deploying advanced energy technologies.
Goodnick’s FOCUS project will develop a photovoltaic device that operates effectively at more than 400 degrees Centigrade (more than 750 degrees Fahrenheit) as the key component of a hybrid concentrating solar thermal power (CSP) system that provides overall higher sunlight-into-electricity conversion efficiency than either a stand-alone photovoltaic system or current CSP systems. It is also to provide a lower dollar-per-watt cost.
The material technology used in the photovoltaic device has already demonstrated its reliability and performance in solid-state lighting applications and should be rapidly applicable to solar systems, Goodnick says.
Holman’s FOCUS project will incorporate photovoltaic cells into large reflectors used by solar power plants to generate heat – and subsequently electricity – from the concentrated sunlight.
The process is designed to improve the efficiency of how solar thermal power plants generate electricity, promising a significant increase in the daytime output of energy while also being able to store solar energy for power generation at night.
Holman says the photovoltaic cells he will use will replace the traditional silver mirrored surface of the large parabolic troughs now used in solar power plants such as the Solana plant in Gila Bend, Ariz.
The cells will absorb visible light and efficiently convert it to electricity, while ultraviolet and infrared light, which would be wasted if it were collected in photovoltaic cells, will instead be reflected onto a black tube at the trough focus. A fluid in the tube will carry the generated heat to be either converted to electricity with a steam turbine or stored for later conversion, he explains.
His project team includes researchers at the University of Arizona, along with Mariana Bertoni, an assistant professor in the School of Electrical, Computer and Energy Engineering.
The system would be designed to be a hybrid between solar panels and a concentrating solar power plant, such as the Solana Generating Station in Gila Bend that allows for energy production after the sun goes down.
“The system we came up with will take the best of both worlds,” Holman told me by phone Thursday. “We will use all the colors of the sunlight, and our system will have high efficiency and storage capacity.”
While regular PV solar panels are flat, Holman’s project will use curved mirrors, like those used at the Solana plant. The PV cells will absorb some light and the rest will be reflected to heat the fluid used to keep the plant running after nightfall, similar to Solana.
“We will absorb all the light we can and efficiently make electricity,” Holman said. “All the light they don’t absorb goes to generating heat.”
By using all the light, the PV mirrors will have higher efficiency, offer storage, have a lower cost, and be more versatile as a power source, he said.
“We are excited,” Holman said. “It’s a unique idea that has real commercialization potential. This money will, I hope, transition from the lab to a marketable product.”
ARPA-E was launched in 2009 to “seek out transformational, breakthrough technologies that show fundamental technical promise but are too early for private-sector investment,” according to a statement.