Distributed Hydrogen Generation & Energy Communities for a zero-emission energy economy

Due to the rapid development of hydrogen vehicles and various National Hydrogen Roadmaps, hydrogen economy has become topical. This evolution is related to the larger and larger availability of renewable energy (mainly from wind and PV) that, due to its intermittency, requires increasing energy storage capability. At the same time, the large availability of small renewable energy converters at lower price allowed the start-up of energy communities merging distributed generation and social innovation. Although there are no literature data on energy savings related to participation in energy communities, some recent studies [1,2] report household energy savings for RES cooperatives located in different European countries (Italy, Portugal, Spain, Belgium, Denmark, France), which can be used as a reference. The report suggests that joining an energy cooperative leads to more than 20% reductions in energy demand, through the adoption of different energy-efficient measures (smart meter installation, leaflets, technical support, engagement activities, software solutions, etc.). The creation of an energy community introduces a more complex link because the members of the community are able to exchange directly their energy and share services. Moreover, the energy communities allow a reduction of the electric grid management issue by structuring groups of electric grid users and prosumers. This because from a technical point of view the energy community could be seen as a micro-grid with a single contact point with the local electric grid. One of the main issues of energy communities, especially if off-grid or located in remote areas, is the energy storage for having both a full consumption of the generated energy and continuous energy supply. Hydrogen Energy Communities (H-EC), i.e. energy communities converting excess energy in hydrogen, for energy storage and other purposes, could be a new opportunity. In fact by using hydrogen as an energy storage media, it is possible to generate back electric energy by fuel cells and to supply fuel to community houses, cars and work vehicles at the same time. Moreover, for each kilogram of hydrogen 8 kg of oxygen are produced by electrolysis. This oxygen can be directly used or sold, offering new services to the community. The authors of the present work already proposed distributed hydrogen generation as one of the hydrogen economy opportunities [3-5]. Starting from the concept "zero-energy hydrogen economy" (ZEH2E) - defined as a zeroenergy system where hydrogen is one of the key energy carriers [6] -, in our view H-EC could be a great opportunity to set-up a new socio-technical system to support energy transition. Furthermore, the developing countries could avoid investing for building up a broad and structured electric grid and, at the same time, would have the opportunities to use innovative energy technologies triggering sustainable energy systems. In this presentation, we will exanimate the possible structure of a hydrogen community tracing the offered opportunities and weakness points.