Multi-apartment residential microgrid with electrical and thermal storage devices: Experimental analysis and simulation of energy management strategies

• Published in: Applied energy 2015-01, Vol.137, p.854-866
• Main Authors: Comodi, Gabriele, Giantomassi, Andrea, Severini, Marco, Squartini, Stefano, Ferracuti, Francesco, Fonti, Alessandro, Nardi Cesarini, Davide, Morodo, Matteo, Polonara, Fabio
• Format: Article
• Language: English
• Subjects: Demand; Distributed generation; Electrical and thermal storage; Energy storage; Near-zero energy buildings; Power plants; Renewable energy; Residential energy; Smart grid; Solar power forecasting; Storage batteries; Strategy; Thermal energy
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2014.07.068

•Thermal & electric storage help to match consumption and renewable production profiles.•Storage increase renewable energy self-consumption and independency from the grid.•Storage reduce bidirectionality and intermittency of PV production.•Computational framework for μ grid simulation under different operating conditions.•The framework can evaluate diverse storage management solutions for future upgrades. The paper presents the operational results of a real life residential microgrid which includes six apartments, a 20kWp photovoltaic plant, a solar based thermal energy plant, a geothermal heat pump, a thermal energy storage, in the form of a 1300l water tank and two 5.8kWh batteries supplying, each, a couple of apartments. Thanks to the thermal energy storage, the solar based thermal energy plant is able to satisfy the 100% of the hot water summer demand. Therefore the thermal energy storage represents a fundamental element in the management of the residential demand of thermal energy. It collects renewable thermal energy during day-time to release it during night-time, effectively shaving the peak of the thermal energy demand. The two electric storages, on the other hand, provide the hosted electrical subsystems with the ability to effectively increase the self-consumption of the local energy production, thus lowering the amount of energy surplus to be sold back to the grid, and increasing the self-sufficiency of the microgrid. For instance, the storage has supported self-consumption up to the 58.1% of local energy production with regard to the first battery, and up to the 63.5% with regard to the second one. Also, 3165 and 3365 yearly hours of fully autonomous activity have been recorded thanks to the first, and the second battery respectively. On the other hand, the yearly average efficiency amounts to 63.7%, and 65.3% respectively, for the first and second battery. In the second part of the paper we propose a computational framework to evaluate the overall performance of the microgrid system, while accounting different operating conditions and energy management policies. From this perspective, the framework acts as a useful modeling and design tool, to assess the opportunity of employing alternative energy management system topologies and strategies. Eight different configurations, with growing complexity, have been derived from the original system on purpose. The simulations, carried out based on real data related to one-year time period, have provid