Strategies to improve light utilization in solar fuel synthesis

The synthesis of fuels using sunlight offers a promising sustainable solution for chemical energy storage, but inefficient utilization of the solar spectrum limits its commercial viability. Apart from fundamental improvements to (photo)catalyst materials, solar fuel production systems can also be designed to improve solar energy utilization by integrating complementary technologies that more efficiently utilize the solar spectrum. Here we review recent progress on emerging complementary approaches to better modify, enhance or distribute solar energy for sunlight-to-fuel conversion, including advanced light management, integrated thermal approaches and solar concentrators. These strategies can improve the efficiency and production rates of existing photo(electro)chemical systems and, therefore, the overall economics of solar fuel production. More broadly, the approaches highlight the necessary collaboration between materials science and engineering to help drive the adoption of a sustainable energy economy using existing technologies. Fuels synthesized using sunlight offer a sustainable solution for chemical energy storage, but inefficient utilization of the solar spectrum has limited their broader viability. This Review looks at how approaches that are complementary to one another can be employed to better exploit solar energy for sunlight-to-fuel conversion.