Multi-scale solar-to-hydrogen system design: An open-source modeling framework

• Python model simulates the H 2 production in a grid-connected PV-electrolyzer system. • Two studied scenarios: battery-assisted 24/7 operation, and solar-only H 2 production. • Typical Meteorological Year data were used to study 3 distinct global locations. • Sines, Portugal, achieves highest PV yield: 1.58 kWh per watt-peak of installed PV. • 24/7 operation reduces hydrogen production costs by ∼35 % compared to solar-only operation. Hydrogen produced from renewable energy holds significant potential in providing sustainable solutions to achieve Net-Positive goals. However, one technical challenge hindering its widespread adoption is the absence of open-source precise modeling tools for sizing and simulating integrated system components under real-world conditions. In this work, we developed an adaptable, user-friendly and open-source Python® model that simulates grid-connected battery-assisted photovoltaic-electrolyzer systems for green hydrogen production and conversion into high-value chemicals and fuels. The code is publicly available on GitHub, enabling users to predict solar hydrogen system performance across various sizes and locations. The model was applied to three locations with distinct climatic patterns – Sines (Portugal), Edmonton (Canada), and Crystal Brook (Australia) – using commercial photovoltaic and electrolyzer systems, and empirical data from different meteorological databases. Sines emerged as the most productive site, with an annual photovoltaic energy yield 39 % higher than Edmonton and 9 % higher than Crystal Brook. When considering an electrolyzer load with 0.5 W EC /W p PV capacity solely powered by the photovoltaic park, the solar-to-hydrogen system in Sines can reach an annual green hydrogen production of 27 g/W p PV and export 283 Wh/W p PV of surplus electricity to the grid. Continuous 24/7 electrolyzer operation increased the annual hydrogen output to 33 g/W p PV , with a reduced Levelized Cost of Hydrogen of €6.42/kg H2 . Overall, this work aims to advance green hydrogen production scale-up, fostering a more sustainable global economy.