Quantifying self-consumption of on-site photovoltaic power generation in households with electric vehicle home charging

Abstract

Photovoltaic (PV) power production and residential power demand are negatively correlated at high latitudes on both annual and diurnal basis. If PV penetration levels increase, methods to deal with power overproduction in the local distribution grids are needed to avoid costly grid reinforcements. Increased local consumption is one such option. The introduction of a home-charged plug-in electric vehicle (PEV) has a significant impact on the household load and potentially changes the coincidence between household load and photovoltaic power production. This paper uses a stochastic model to investigate the effect on the coincidence between household load and photovoltaic power production when including a PEV load. The investigation is based on two system levels: (I) individual household level and (II) aggregate household level. The stochastic model produces theoretical high-resolution load profiles for household load and home charged PEV load over time. The photovoltaic power production model is based on high-resolution irradiance data for Uppsala, Sweden. It is shown that the introduction of a PEV improves the self-consumption of the photovoltaic power both on an individual and an aggregate level, but the increase is limited due to the low coincidence between the photovoltaic power production pattern and the charging patterns of the PEV.