Energy, Environmental and Economic Effects of Electric Vehicle Charging on the Performance of a Residential Building-integrated Micro-trigeneration System

The widespread adoption of electric vehicles (EVs) and electric heat pumps (EHPs) would result in radically different electric household demand characteristics, while also possibly posing a threat to the stability of the electrical grid. Micro-cogeneration (MCHP) is considered by the European Community as one of the most effective measures to save primary energy and reduce emissions. The utilization of EVs and EHPs could be a way to boost MCHP profitability and micro-cogeneration systems can also help in reducing the potential negative effects of EVs and EHPs on electric distribution networks. In this paper a micro-trigeneration system (composed of a 6.0 kWel cogeneration device feeding a 4.5 kWcool electric air-cooled vapor compression water chiller) serving an Italian residential house was investigated by using the dynamic simulation software TRNSYS. The charging of an electric vehicle was considered by analyzing a set of EV charging profiles representing different scenarios. The simulations were performed in order to evaluate the capability of cogeneration technology in (i) alleviating the impact on the electric infrastructure, (ii) saving primary energy, (iii) reducing the carbon dioxide equivalent emissions and (iv) the operating costs in comparison to a conventional supply system based on separate energy production.