- Solar cogeneration of electricity and steam demonstrated with 85.1% efficiency
- Steam output reached 248°C, while average CPV cell temperatures remained <110°C
- Transmissive PV module field validated for >8 h at >300 suns concentration
- System levelized cost of heat of 3¢/kWth for an installation in San Diego, CA
In solar panel installations of flat plate photovoltaics and parabolic trough collectors consume significant space and have high system losses. Therefore researchers at Tulane University have developed a hybrid solar energy converter that generates electricity and steam with high efficiency and low cost.
In their model, they used an all-in-one spectrum-splitting hybrid receive by which electricity and high-temperature heat can be generated with a single efficient system. As shown in figure above.
The work led by Matthew Escarra, associate professor at Tulane, and Daniel Codd, associate professor at the University of San Diego.
The research is detailed this month in the science journal Cell Reports Physical Science. Researchers from San Diego State University, Boeing-Spectrolab and Otherlab were also part of the project.
The hybrid converter utilizes an approach that more fully captures the whole spectrum of sunlight. It generates electricity from high efficiency multi-junction solar cells that also redirect infrared rays of sunlight to a thermal receiver, which converts those rays to thermal energy.
The thermal energy can be stored until needed and used to provide heat for a wide range of commercial and industrial uses, such as food processing, chemical production, water treatment, or enhanced oil recovery.
The team reports that the system demonstrated 85.1 percent efficiency, delivered steam at up to 248°C, and thus the cost of power consumption reduces to 3 cents per kilowatt hour.
Previously the design of solar thermal systems often sacrifices electrical efficiency for higher temperature heat output by physically coupling cell temperature to thermal output temperature. In which cells must operate at higher temperatures than the output heat transfer. To achieve thermal energy temperatures in the range of 250°C, as reported here, cells must operate at ∼≥300°C. but here the cell temperature remain at 110°C that increases its efficiency.
The team want to make their unique concept available in market as soon as possible. Currently with follow-on funding from the Louisiana Board of Regents and Reactwell, a local commercialization partner, they are continuing to refine the technology and move towards pilot-scale validation.
“We are pleased to have demonstrated high performance field operation of our solar converter,” Escarra said, “and look forward to its ongoing commercial development.”