Green Hydrogen Generation by Water Photoelectrolysis: Economic and Environmental Analysis

Water photoelectrolysis cells based on photoelectrochemical water splitting seem to be an interesting alternative to other traditional green hydrogen generation processes (e.g., water electrolysis). Unfortunately, the practical application of this technology is currently hindered by several difficulties: low solar-to-hydrogen (STH) efficiency, expensive electrode materials, etc. A novel concept, based on a tandem photoelectrolysis cell configuration with an anion-conducting membrane separating the photoanode from the photocathode, has already been proposed in the literature. This approach allows the use of low-cost metal oxide electrodes and nickel-based co-catalysts. In this paper, we conducted a study to evaluate the economic and environmental sustainability of this technology, using the environmental life cycle cost. Preliminary results have revealed two main interesting aspects: the negligible percentage of externalities in the total cost (<0.15%), which means a positive environmental impact, and as evidenced by the net present value (NPV), there are potentially financial conditions that favour future investment. In fact, an NPV higher than 150,000 EUR can be achieved after 15 years.