Limitations on the Efficiency of the Solar Photoreduction of Carbon. Final Report June 1982-May 1985

摘要

The purpose of the project was to clarify the thermodynamic and kinetic limits on the efficiency of solar photochemistry in general, and the solar photoreduction of carbon in particular. A 'thought experiment' was devised which provides a non-mathematical proof of the generality of the Carnot limitation on the efficiency of converting light energy into work. Proof was obtained that a simple of hybrid solar energy converter can have both very high theoretical efficiency (66%) and properties which are compatible with construction of a practical device, this kind of converter combines the electron-transfer aspect of photoelectrical and photochemical cells with the high-temperature aspect of thermal solar conversion. Losses due to the finite width of the electronic spectral bands of photochemical systems were found to be approximately proportional to the square of this width, and to cause a significant loss in achievable conversion efficiency. Bilinear analysis of fluorescence from photosynthetic systems permitted determination of the fluorescence spectra of photosystems I and II.