Home energy optimization using vehicle-to-home

<ns4:p>Background Vehicle to home (V2H) involves using the energy stored in Electric Vehicle (EV) batteries to lower home energy costs by shifting energy use from high-cost periods to low-cost periods, including charging EVs overnight. This approach also helps manage grid demand peaks and decarbonize the transport and energy sectors. Methods This study models a home energy system, integrating grid connections, household energy demands, heating systems, EVs and photovoltaic (PV) panels. The optimization model aims to utilise the EV battery and smart electricity price tariffs to minimize home energy costs. By adopting a 3-tier (Day/Night/Peak) electricity tariff structure, the model compares the results from uncontrolled, flexible and V2H charging strategies. The sensitivity of the cost savings obtained from V2H to a range of parameters such as household, electricity usage, PV installed capacity, tariff differences and EV parameters are also investigated. Results By utilizing V2H strategy, the results found that V2H had the overall best savings, with the energy cost reductions up to 30% for non-commuting users and by 27.5% for commuting users. Under the 3-tier tariff structure, the growth of PV capacity leads to a decline in V2H cost savings. V2H has a 25% reduction in electricity costs without PV and a 37% reduction in electricity costs with a 6-kW PV system, compared to an uncontrolled charging strategy. Conclusions Under the 3-tier tariff structure, V2H cost savings are achieved by shifting large portions of residential electricity demands into off-peak hours with low electricity tariffs, thus lowering the electricity costs and reducing the grid stress during peak hours with the better utilization of rooftop PV generation. By assuming a 4% discount rate, V2H has its Discounted Payback Period (DPP) within one decade with the initial investment cost of a bidirectional charger lower than €7000.</ns4:p>