Exploring Renewable Energy Communities integration through a hydrogen Power-to-Power system in Italy

Increasing renewable power generation is a way to decarbonize power system. Hydrogen can be used as energy vector in a Power-to-Power (PtP) system to better manage the energy flow from renewables to users. Renewable Energy Community (so called REC) is proposed by RED II European directive to involve final users in energy management and to create conditions for local development of renewables. This work introduces a PtP hydrogen-based system, involving RECs to increase electric autarchy (self-sufficiency) of final users who have installed renewables in their electric market area (proximity of users). A double REC system is proposed in which the first REC generates renewable energy through a hybrid photovoltaic and wind system and excess energy is stored as hydrogen generated through electrolysis; the second REC is powered by the hydrogen produced by the first one by means of fuel cell. Both RECs are connected to the power grid from which they can draw energy as well as put energy into it. Despite low round trip efficiency of a Power-to-Power hydrogen supply chain, the system increases users’ autarchy substantially (from 68.6% to 83.7%). Current costs of apparatus despite the public subsidies to REC makes the proposed system not sustainable from an economic point of view.