Innovative household systems based on solid oxide fuel cells for the Mediterranean climate

Publication of the 2010/31 EU Directive is proof of the importance of energy saving in buildings. European Union policies are oriented to increase the levels of energy saving, renewable energy and cogeneration, with the aim to decrease greenhouses emissions and energy dependence. Publication of the 2004/8/EC Directive indicates that cogeneration is considered as a solution to reach the goal of energy efficiency. This paper presents an innovative system based on solid oxide fuel cells (SOFCs), an air source heat pump (ASHP), and an integration system to cover a part of the heating demand of a building. Two different integration systems are proposed: electric heater and condensing boiler. Heat storage is also considered to store waste heat when it is unused. An innovative parameter, the electric equivalent load, is proposed: it has the function of characterizing not only electricity consumption but also heating and cooling demands. The aim is to maximize efficiency while minimizing the mismatch between different forms of energy consumption. The proposal is to verify the energy efficiency of the system used to cover energy demands of a residential building located in a Mediterranean area (Trapani, south of Italy). The results of the simulations are analyzed with thermodynamics and techno-economic benchmarks, considering different economic scenarios. The calculations indicate a high primary energy saving and profitability for the proposed system.