Ben Welter - Thursday, August 27, 2015
Which solar energy technology will prevail, photovoltaic or concentrating solar power? Matt Orosz, cofounder of STG International and co-principal investigator at Cogenra Solar, says combining the two might enable integration of low-cost thermal energy storage and carve out a place in the energy grid's renewables-driven future.
"To reduce the need for electrical storage and take advantage of the increasing efficiency and diminishing costs of PV," Orosz writes on SPIE.org, "the US Department of Energy's Advanced Research Projects Agency–Energy (ARPA-E) has created the Full-Spectrum Optimized Conversion and Utilization of Sunlight (FOCUS) program to link PV and CSP.
"Several groups have responded to this challenge with innovative ideas: a team from Arizona State University is replacing traditional PTC mirrors with PV cells layered under an IR-reflective film that sends light to a traditional CSP absorber tube. At Cogenra Solar, we are keeping traditional PTC mirrors but interposing a secondary dichroic mirror in front of the CSP tube to reflect the visible part of the spectrum onto an additional receiver based on concentrated PV. Both these efforts attempt to split the solar spectrum to maximize the energy flux that corresponds to the PV band gap and avoid the temperature incompatibility between PV and CSP."http://spie.org/x399.xml?WT.svl=mddp1