Facsa The HACDOS project has concluded. This research project explored new ways to produce renewable hydrogen from wastewater using specially designed solar panels. The technology analyzed aims to convert used water into a clean energy source while simultaneously reducing its polluting load.
The project has been developed by a consortium made up of Facsa -leading entity-, Enagás, the Rovira i Virgili University and the Eurecat technology center, with the collaboration of the Besòs Tordera Consortium, which has provided the facilities of the Granollers WWTP for the pilot tests.
HACDOS was conducted between October 2022 and November 2025 and was launched with a dual objective: to explore more sustainable alternatives for treating wastewater and, at the same time, to generate hydrogen in a more accessible way with less environmental impact. Unlike conventional technologies, which often rely on fossil fuels or high electricity consumption, this research focused on solar photocatalysis, a process that harnesses sunlight to activate materials capable of generating hydrogen.
The first phase of the project involved studying different types of wastewater in the laboratory to determine how much hydrogen they could produce. Following these tests, the team built two prototype photocatalytic solar panels, one 1 m² and the other 10 m², which were installed at the Granollers Wastewater Treatment Plant to be tested under real-world conditions, using wastewater and natural sunlight.
The results show that, although the technology is still in its early stages and the amount of hydrogen produced is low, the project confirms its potential and opens new avenues for further development. The knowledge gained will allow for the optimization of the design of future photocatalytic systems and reinforces the commitment to new solutions that combine water management and renewable energy. With HACDOS, the consortium establishes a solid foundation to drive further development and explore innovations that contribute to a more sustainable energy transition.
This project has a total budget of €555,116.72. Project CPP2021-008619, funded by MCIN/AEI /10.13039/501100011033 and by the European Union NextGenerationEU/PRTR.
