Comments on Net Energy for Solar Thermal Electric by Lorin Vant-Hull, Emeritus Professor of Physics, Univ. of Houston

I have done a careful evaluation of the EROI or energy payback based on the detailed commercial Central Receiver plant design which served as the reference for the 10 MWe Solar One plant (incorporating oil thermocline storage), and a similar analysis for the second generation dispatchable plant incorporating two-tank molten salt storage (Solar Two). In both cases I obtained energy payback periods of about 18 months assuming all electric input to electric output, and less than 6 months assuming petroleum input to electric output. As all these plants are designed with a 30 year life, the EROI comes out at 20 electricity in to electricity out, or 60 petroleum in to electricity out. These results were reported in Natural Resources Journal V25, pp 1099-1117 (1985), in Perspectives in Energy, V2, pp157-166,(1992-3), in the 1989 Energy and the Environment Conference Proceedings, Sept 1989, Denver Colorado, and in Solar Today, Nov/Dec issue, 1992, with a correction to note the 35% efficiency of a typical oil fired plant appearing in the next issue letters page.