Hydrogen and Chemicals from Solar Energy: The Quest for High-Efficiency Strategies

摘要

The bottleneck, with respect to scientific- technological challenges and economical feasibility, for a global hydrogen technology, is seen in maximizing solar energy conversion efficiency. The present development is too slow and too much focused on conventional technologies of silicon and development of thin layer cells of comparatively rare, toxic elements. Suggested key strategies include development of advanced thin layer tandem photovoltaic cells of abundant materials which are taylored towards optimization of electrolysis. Biomass gasification technology is to be developed as the most efficient source of chemical energy. As a new strategy for the generation of fuel, food, materials and hydrogen a solar version of a deep sea biomass generation process based on a sulfur cycle is experimentally demonstrated. Energy conversion efficiencies between 10 and 15 % are feasible. Solar electricity and heat are used to reduce iron sulfate to iron sulfide, which bacteria use as energy source for carbon dioxide fixation. A strategy, both in terms of technological milestones and political challenges is presented.