SOLAR-H2 · Solar Artificial Trees for Hydrogen on-Demand Production

The SOLAR-H2 project introduces a groundbreaking artificial tree (AT)-like technology for distributed, on-demand H2 production, designed for zero-carbon communities and off-grid applications. Unlike conventional electrolysers requiring high-purity water and grid electricity, this system has near-zero operational costs, leveraging solar energy and capture of reactants from the ambient. The aim is to develop a showcase prototype for the Solar Hub under development at the Univ Messina to present to stakeholders the potential of AT technologies. The innovative approach integrates photo-electrocatalysis, where CO2 and H2O are converted into H2 and formic acid (FA) using sunlight. The latter acts as a hydrogen storage medium, enabling on-demand or continuous H2 production, even during the night, through catalytic decomposition. Additionally, the system ensures a closed-loop CO2 recirculation, with minimal losses compensated by external CO2 sources, making it a highly sustainable and carbon-efficient solution. Building upon the ERC Synergy SCOPE project, SOLAR-H2 aims to advance the technology to TRL4. This will involve scaling up to a small-scale demonstrator, improving performance and gas-diffusion electrodes as well as the cell for stable continuous operation, and integrating the systems for capturing reagents and the storage/decomposition-on-demand of FA. The project assesses techno-economic and socio-environmental aspects, along with a market analysis to identify key barriers and opportunities. The exploration strategy is to build a first demonstrator for the Solar Hub to foster this important area of solar-to-chemical conversion and lay the foundation for a spin-off company, positioning formic acid as a breakthrough hydrogen vector in the clean energy transition. By bridging the gap between lab-scale research and industrial feasibility, SOLAR-H2 will de-risk the transition paving the way for large-scale adoption of sustainable H2 production technologies.