Renewable hydrogen potential for low-carbon retrofit of the building stocks

Energy-related GHG emissions, mainly from fossil fuels combustion, account for around 70% of total emissions. Those emissions are the target of the recent sustainability policies. Indeed, renewables exploitation is considered widely the weapon to deal with this challenge thanks to their carbon neutrality. But, the biggest drawback is represented by the mismatching between their production and users consumption. The storage would be a possible solution, but its viability consists of economic sustainability and energy process efficiency as well. The cutting edge technologies of batteries have not still solved these issues at the same time. So, a paradigm shift towards the identification of an energy carrier as storage option, the so called Power-to-Gas, could be the viable solution. From viability to feasibility, a mandatory step is required: the opportunity to integrate the new solution in the proven infrastructures system. Thus, the recent studies on Hydrogen (H2) enrichment in Natural Gas, demonstrating a lower environmental impact and an increase in energy performance, are the base to build the hydrogen transition in the urban environment. The aim of this paper is to evaluate the environmental benefits at building and district scale.