Techno-economic analysis of the direct solar conversion of carbon dioxide into renewable fuels

Direct conversion of carbon dioxide (CO2) using sunlight into commercially viable renewable fuels will be one key solution for decarbonization and storing renewable solar energy. However, the direct conversion of CO2 using sunlight faces uphill challenges, especially the techno-economic viability (TEV), as the produced fuels must compete with fossil fuels or at least with fossil fuel alternatives, which are cheap. This work proposes an innovative structure design for photoelectrochemical reduction of CO2 into renewable fuels and performs a detailed techno-economic analysis (TEA) using a generalized gross margin (GM) model. The proposed structure uses low-cost and earth-abundant crystalline silicon-based photoanode with triangle nano-strips on a thin-film substrate to efficiently convert solar energy into renewable fuels. The proposed structure shows 20.01% of power-conversion efficiency (eta(PEC)). The techno-economic GM model considers all relevant cost parameters to assess the TEV of the produced hydrogen (H-2) and hydrocarbon (C-1-C-3) fuels from CO2 reduction processes. The TEV of the produced renewable fuels is analyzed and presented against critical device parameters, such as the photocurrent density (J), catalyst's durability (t(dur)), Faradaic efficiency (FE), and catalyst cost (C-cat). We also analyzed how sensitively the TEV of the produced fuels depends on the uncertainty of different cost parameters assuming base-, worst-, and optimistic-case scenarios. We find that carbon monoxide (CO) and formic acid (HCOOH) fuels will be commercially viable in the base case, while H-2 and propanol (C3H7OH) will be only in the optimistic case.