Thermo-Economic Analysis of a Photovoltaic-Fuel Cell Hybrid System With Energy Storage for CHP Production in Household Sector

The penetration of renewable sources, particularly wind and solar, into the grid has been increasing in recent years. As a consequence, there have been serious concerns over reliable and safety operation of power systems. One possible solution, to improve grid integrity, is to integrate energy storage devices into power system network: storing energy produced in periods of low demand to later use, ensuring full exploitation of intermittent available sources. Focusing on photovoltaic energy system, energy storage is needed with the purpose of ensuring continuous power flow to minimize or to neglect electrical grid supply. A comprehensive study on a hybrid micro-CHP system based on photovoltaic panels using hydrogen as energy storage technologies has been performed. This study examines the feasibility of replacing electricity provided by the grid with a hybrid system to meet household demand. This paper is a part of an experimental and a theoretical study which is currently under development at University of Bologna where a test facility is under construction for the experimental characterization of a small scale cogenerative power system. This paper presents the theoretical results of a hybrid system performance simulations made of a photovoltaic array an electrolyzer with a H₂ tank and a Proton Exchange Membrane fuel cell stack designed to satisfy typical household electrical demand. The performance of this system have been evaluated by the use of a calculation code, in-house developed by the University of Bologna. Results of the carried out parametric investigations identify photovoltaic and fuel cell systems’ optimal size in order to minimize the purchasing of electrical energy from the grid. Future activities will be the tuning of the software with the experimental results, in order to realize a code able to define the correct size of each sub-system, once the load profile of the utility is known or estimated.