Economics-Informed Discovery of Solar Energy Conversion Systems

Current methods of solar energy conversion are not yet sufficiently economical to allow solar to be a competitive global energy source. This project investigates various solar energy conversion systems to identify which have the best economic potential, and how best to implement these systems. A technoeconomic analysis was conducted of available chemicals produced via solar energy conversion to identify the best candidates. Factors considered were the different materials’ market sizes, market values, and energies of formation. Several materials have high market values but too-low of market sizes, or vice versa. Additionally, some materials require too high of an energy input to make large-scale production feasible. Copper metal was shown to be one of the products with the best potential. Deposition of copper on a solar cell could allow the production of a high-value product that would increase the profitability of a solar energy-driven production process, thus making solar competitive with conventional energy sources. Investigation into producing copper via solar energy conversion and photo-electrodeposition in a continuous-flow reactor is now being conducted to optimize its economics and feasibility. Deposition of copper metal onto a gallium arsenide solar cell illustrated feasibility of the idea, the copper deposited well and was removed easily. However, gallium arsenide solar cells are expensive, so a scalable alternative is the use of silicon solar cells. Deposition of copper metal on a silicon solar cell posed challenges that will need to be overcome. Poor deposition amounts and rates and difficulty in harvesting the copper from the surface of the cell will have to be solved to implement a practical copper deposition system. Possible solutions include the use of flow options, surface pretreatment, sonication, and precipitation. Future investigation will look into these, and any other, possibilities to efficiently remove the copper and create a continuous-flow process. A more-thorough economic analysis will also be conducted to show the scalability of a copper deposition process.