Green hydrogen vs. batteries for energy communities

Nowadays, green hydrogen is seen as the solution for decarbonising the more pollutant and the hard to abate human activities [1-3]. Consequently, huge efforts are in place in many countries to reach enough hydrogen production for this purpose, this considering large hydrogen production plants and international hydrogen trade. Large green hydrogen production plants pose a number of issues related to the energy supply, the hydrogen transport and distribution and, not the least, the social acceptance. The authors’ research group supports an approach based on the hydrogen distributed production and on site utilisation, coupled with the valorisation of the by-products of hydrogen production and application [4-7], and considering also the technologies using the local available residual biomasses and bio-wastes as feeds. Based on this approach, in the 2020 edition of HYPOTHESIS conference [8] the concept of hydrogen based energy community was proposed. In the present work, we report the results related to a case study of a small Italian energy community (10 families) living in an Italian city, and using solar energy both for electricity and hot water production. In this study, the PV/hydrogen system was compared with a PV/battery system, both coupled with a solar boiler, for evaluating if hydrogen based systems could be competitive or not with the battery system. As Italy extends from North to South for about 1,300 km, calculations have been repeated for 3 representative cities located in North, Centre and South of Italy. After a technical and energetic analysis of the two systems, an evaluation of the costs and revenues was carried out. Reference costs for the components have been assessed by a comparison between scientific literature data and a market analysis carried out on internet and by interviews to local suppliers and professional installers. The results of the study show that hydrogen at so small size is not still competitive with batteries, but it offers some solutions that could have an appeal for end users.