PV–EV Integration in Residential Buildings: the Role of Occupant Travel Behaviour and EV Model Choice

The rapid expansion of residential photovoltaic (PV) systems and electric vehicles (EVs) is fundamentally reshaping household electricity demand, charging behaviour, and energy economics. In response, this study develops a unified optimisation framework that jointly integrates PV generation, household load, EV charging behaviour, and both home and public fast-charging options, enabling a realistic assessment of PV–EV systems across diverse behavioural and technical conditions. To capture variability in real-world usage, 3000 distinct scenarios are constructed by combining six representative household demand profiles, five widely used EV models, and 100 scenarios of travel patterns. Optimal PV capacities are determined using a CPLEX-based optimisation model that explicitly accounts for time-varying electricity tariffs and charging availability. The results demonstrate that optimal PV sizing and system configuration are highly sensitive to mobility behaviour and EV characteristics, with required PV capacity varying by up to 50% for the same household. While PV–EV integration consistently reduces electricity costs, financial outcomes depend strongly on the alignment between PV generation, charging opportunities, and daily travel schedules. By explicitly modelling both home and public charging, the analysis quantifies when public fast charging becomes financially advantageous, providing actionable insights for EV users and system planners. Sensitivity analysis further reveals that changes in EV type after system installation can increase annual electricity costs by up to 44%, highlighting the importance of robust PV–EV planning under evolving user behaviour. Battery capacity emerges as the dominant factor: upgrading to an EV with a larger battery generally improves economic performance by absorbing surplus PV generation, whereas switching to an EV with a battery approximately 10 kWh smaller can significantly worsen outcomes by increasing reliance on peak-tariff grid imports and public charging.