Thermophotovoltaic systems for achieving high-solar-fraction hybrid solar-biomass power generation

Medium operating temperature hybrid solar-biomass TPV power plant design requires complex integration of multiple high temperature processes with low band-gap TPV cells. A 0.72 eV band-gap GaSb TPV cell has been used in thermophotovoltaic (TPV) systems operating at temperatures above 1400 degrees C. Low band-gap TPV cells, such as InGaAs (E-g = 0.55 eV) and InAs (E-g = 0.36 eV) could enable a TPV system to operate optimally at temperatures approximate to 1000 degrees C. To examine this, two hybrid solar-biomass TPV system configurations are studied using TRNSYS simulation that incorporates a new algorithm for TPV. It is found that in a high solar fraction CSP power plant, a TPV system could recover surplus thermal energy gained from solar energy at mid-days that would otherwise be unused.