Multi-objective sizing and control of renewable energy communities with hybrid battery–hydrogen storage

The accelerating energy transition is promoting the widespread deployment of renewable technologies and collective self-consumption models such as energy communities. This study proposes an optimal sizing and energy management framework for a grid-connected Renewable Energy Community (REC) integrating hybrid generation—photovoltaic (PV) and wind turbines—and hybrid storage, combining batteries with a hydrogen Power-to-Power (PtP) subsystem. The methodology also evaluates the impact of electric vehicle (EV) charging through three representative residential load profiles, including standard and off-peak EV charging. Four case studies are investigated, from a PV-battery baseline to advanced configurations incorporating wind generation, hydrogen storage, and a fuzzy-logic energy management system (EMS). A multi-objective metaheuristic optimization generates a Pareto-optimal set of solutions, revealing the trade-offs among key performance indicators: net present value (NPV), grid dependence (GD), self-sufficiency ratio (SSR), and greenhouse gas (GHG) emissions. The techno-economic-environmental analysis identifies configurations that best balance these competing objectives according to different stakeholder priorities, rather than simultaneously optimizing all KPIs. Results show that hybrid PV-wind generation combined with batteries consistently improves all KPIs, while substituting batteries with hydrogen reduces emissions but at higher cost and lower efficiency. Hybrid storage offers clear benefits only for minimizing grid dependence, whereas the fuzzy-logic EMS provides limited advantages over simpler rule-based control. EV charging affects component sizing but not the relative performance hierarchy among solutions. These findings arise directly from the quantitative optimization results: across more than 2000 Pareto-optimal solutions, battery-only configurations systematically yield higher NPV and round-trip efficiency, whereas hydrogen-based storage becomes advantageous only in scenarios prioritizing extreme reductions in grid dependence or GHG emissions. This evidence-based comparison strengthens the distinction between economically and environmentally optimal designs.