Role of electric vehicles in PV self-consumption optimisation

One of the problems with increasing photovoltaic (PV) penetration is related to the fact that the actual generation profiles usually do not match the energy demand of a typical domestic house. There are a number of different ways which can be used to bridge this energy gap including demand side management (DSM) and energy storage techniques, allowing manipulation of energy consumption and distribution within households. This paper analyses an alternative way for increasing self-consumption of distributed energy in a zero carbon house serving as an office for research staff at the University of Nottingham. The initial focus of the work looks at electric vehicle (EV) as alternative energy storage or consumption solution for excess electricity generated from an onsite PV system. The energy distribution within the office as well as EV charging profiles were obtained and evaluated using a state-of-the art wireless control and monitoring platform. One year data of PV exported electricity was compared to the average diurnal office energy demand. Any excess PV export then was evaluated against different EV charging approaches in order to find and relate, if any, self-consumption benefits of localised PV generation. Thus, the actual observed PV generation and EV charging profiles with controlled and uncontrolled EV charging strategies were analysed to find any possible reduction in exported electricity, increasing PV power utilisation onsite. The results show that the smart EV charging methods can increase self-consumption of electricity generated from PVs as well as may moderate the likely rise in peak energy demand associated with increasing EV penetration in the domestic built environment. In addition, results were shown that the energy demand and costs associated with charging EV batteries could be reduced when utilising PV export output.