Scientists in Spain have developed a cheap, easy-to-deploy hydrogen system powered by discarded solar panels. The residential solution reportedly achieves a levelized hydrogen price of approximately $5.8/kg.
A Chilean research team has developed a residential-scale system to produce green hydrogen using discarded photovoltaic modules.
The proposed solution combines end-of-life solar panels, which still retain 80% to 90% of their original capacity, with a proton exchange membrane (PEM) electrolyzer. Unlike conventional systems, which rely on power electronics such as inverters or maximum power point trackers, this approach uses internal reconfiguration of the PV module to tailor the current-voltage curve to the electrolyzer’s requirements. This eliminates the need for additional components and reduces system complexity, the scientists explained.
The system configuration changes the electrical architecture of the panel by connecting subsets of cells in parallel, allowing for more efficient coupling to the electrolyzer. “By accessing internal busbars to create custom parallel substrings, this voltage matching strategy can be generalized to other standard architectures, such as 60- or 96-cell modules,” the research team said. “This flexibility allows the system to overcome the heterogeneity of waste panels, enabling customized voltage tuning and the isolation of localized cell faults in different PV technologies.”
According to the researchers, the system achieves an annual energy yield equal to 88% of the yield obtained with power electronics-based optimization, while maintaining operational simplicity, which is a key advantage for residential use.
Experimental results, validated under real conditions, show a daily hydrogen production of approximately 345 liters. This significantly exceeds the estimated basic requirement for basic household uses such as cooking or heating, which is approximately 120 liters per day. The system achieves a solar hydrogen efficiency of approximately 7%, utilizing more than 70% of the theoretical maximum for simplified configurations.
From an economic perspective, the system delivers a levelized hydrogen cost (LCOH) of approximately $5.8/kg, representing an 18% reduction compared to more complex reference systems. The cost benefit is mainly due to the elimination of power electronics and the reuse of existing PV modules.
The researchers say the concept could help tackle two challenges at once: the growing amount of photovoltaic waste and the high cost of green hydrogen. Reusing panels extends their lifespan and reduces pressure on raw material supply chains.
However, the authors note limitations, including lower efficiency compared to systems with advanced electronic controls and dependence on variable solar radiation. Nevertheless, they believe that the system’s simplicity, low cost and ease of integration make it a promising option for decentralized applications.
The work, entitled “Green hydrogen production using discarded photovoltaic panels for household applications”, was published in Energy conversion and management.
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