Solar bacterial biomass bypasses efficiency limits of photosynthesis

Abstract

A new kind of solar energy technology is proposed here which will allow biomass to be produced at efficiencies higher than the theoretcial limits of photosynthesis and at one order of magnitude higher than by present processes. Its principle is to produce the chemically simple inorganic energy source of certain auto-trophic bacteria by solar thermal, photoelectrochemical or solar powered electrochemical methods and to grow these bacteria, for example Thiobacillus ferrooxidans, which can live from the oxidation of ferrous to ferric iron in continuous cultures in the dark. A remarkable prospect of this novel strategy for gathering solar energy would be that biomass for food, fuels and materials could be produced in largely automatic and compact factory-type installations on arid and infertile land, to which the limited amount of water which is needed to fix CO₂ and is extracted in the form of dry organic products may be transported as a raw material.