Solar thermal systems — flat plate collector (Hottel-Whillier model, FR, UL, FRUL), evacuated tube collectors, concentrating solar power (parabolic trough, Fresnel, heliostat/tower, dish-Stirling), optical efficiency, concentration ratio, working fluids (water, glycol, thermal oil, molten salt), solar fraction, storage sizing, TRNSYS simulation, ASHRAE 93 collector test, and net metering for solar thermal.
