Integration of Green Hydrogen and Heating/Cooling Subsystems to a 40 kWp Photovoltaic-60 kWh Battery Energy Storage System Living Lab Nanogrid

Abstract

Decentralized energy systems can contribute to the maximization of the energy share of renewable energy, especially when such systems are integrated with effective and practical energy storage and other energy efficient elements. In this study, an application of the microgrid concept is investigated in terms of a small-scale system, which can operate in both grid-connected and island (autonomous) modes, as dictated by onsite power generation and load demand. Specifically, a solar photovoltaic-battery energy storage system (PV-BESS) nanogrid system has been recently developed at the premises of the Solar Photovoltaic Technology Laboratory of the University of Cyprus, in an effort to create a Living Lab pilot system. The next step includes the integration of additional energy conversion and storage systems to this existing PV-BESS system, namely green hydrogen, and heating/cooling subsystems. The green hydrogen subsystem will include three main components: a water electrolyzer able to convert excess PV-generated electricity, a hydrogen storage unit to store the generated green hydrogen, and a fuel cell unit to re-generate electricity when solar energy is unavailable. The heating/cooling subsystem will include two main components: a reversible water heat pump system to provide space heating, space cooling and domestic hot water, and a thermal energy storage unit to store heat and use it when needed. Such a system is expected to further increase both self-sufficiency and self-consumption rates, while reducing dependency from the central power grid.