Photovoltaic systems with secondhand batteries of electric vehicles and their social implementation in times of COVID-19

ABSTRACT

As people spend more time at home during the COVID-19 pandemic, residential electricity consumption is increasing. To prevent global warming, the increased electricity consumption should be covered by renewable energy, e.g. photovoltaic (PV) power generation. However, PV systems are unstable power sources due to weather conditions;it is necessary to stabilize the residential PV power supply by using batteries. Now, electric vehicles (EV) are beginning to spread, especially in emerging countries. The EV batteries are useful for stabilizing the residential PV power supply. The idea of V2X, using EVs as batteries for buildings, is well-known but still a work in progress. Instead of V2X, we started an experiment based on another idea that we use the secondhand EV lithiumion batteries to stabilize the residential PV power supply. Since 2017, the experiment has been conducted in Yamaguchi in order to evaluate the self-sufficiency of a PV system with the stationary battery, which reused secondhand EV lithium-ion batteries as its components. Analysis of the experimental data revealed that the self-sufficiency of PV system was improved by up to 1.75 times with the stationary storage battery compared to the case without the stationary storage battery. © 2021 IEEE.