Design and Implementation of Renewable Hydrogen-Based System for Social Housing Decarbonization

The energy transition towards a decarbonized economy requires focused and ambitious policies that must be taken through the agreement of governments, stakeholders, and private companies. The intermittency of renewable energy sources (RES) makes it necessary to implement energy storage systems (ESS) that allow for an uninterrupted supply of low-carbon power. Energy generation and consumption activities are responsible for 75% of global CO 2 emissions. Particularly, energy use in commercial and residential buildings is the third major contributor after industry and agricultural activities 1 . In this context, hydrogen as an energy vector facilitates and enhances RES penetration in the energy mix. Moreover, it can be employed as a fuel or commodity to obtain other chemical compounds 2 . Hence, hybrid renewable hydrogen-based systems (RHS) can play a key role in buildings decarbonization 3 . On top of that, green hydrogen may tackle other problems such as energy poverty faced by the most vulnerable and disadvantaged citizens 4 . In this context, the SUDOE ENERGY PUSH project proposes an innovative solution for the overall management of social housing located in the regions of southwestern Europe to increase the energy efficiency of public buildings and improve the living standards of vulnerable citizens. Through passive renovation, RES, and BIM methodology, it aims at reducing the consumption and emissions of buildings and at improving the comfort of the inhabitants, overcoming the risks of energy poverty. In this context, a pilot plant combining RES and hydrogen technologies has been implemented in a social housing in Cantabria (Spain) to demonstrate the feasibility and benefits of the system. This demonstration is aimed at achieving energy self-sufficiency of the house throughout the year while saving remarkable amounts of primary energy and CO 2 emissions. The primary source of the system will be solar photovoltaic (PV) energy. To combat PV intermittency and harness the periods with energetic surpluses, different energy storage systems (ESS) have been installed within the pilot plant: lithium-ion batteries for short-term energy storage and hydrogen-based technologies for seasonal energy storage. Furthermore, a compressor has been included to reduce the hydrogen storage volume and a programmable logic controller (PLC) rules the operation of the configuration based on the state of charge of the batteries, so that the PLC decides which equipment operates at wh