MK introduces vanadium ion battery EV charging energy storage system for the first time in Japan

Major taxi company MK (Minami Ward, Kyoto City) has become the first company in Japan to introduce an energy storage system using vanadium ion batteries for charging EV taxis. They are characterized by lower risk of ignition and higher durability than lithium-ion batteries, and are expected to reduce electricity bills.本社で1年間の実証実験を行った上で、設置台数を増やしていく方針。

According to MK, the installed system is manufactured by South Korean company Standard Energy and is approximately 3 meters tall, wide, and deep. The battery storage capacity is 75 kilowatt hours, and the fast charger output can be up to 150 kilowatt hours. Vanadium-ion batteries are attracting attention as a next-generation energy source that has an extremely low risk of ignition compared to existing lithium-ion batteries. In terms of lifespan, lithium-ion batteries can be recharged 3,000 to 6,000 times in about seven years, while vanadium-ion batteries can be recharged about 15,000 times in about 15 years.

Rapid charging of EVs consumes a large amount of electricity in a short period of time, which poses issues such as a burden on the power grid and increased costs due to high contracted electricity costs.If multiple EVs are rapidly charged at the same time, the basic electricity charge will rise. In the demonstration experiment, some EV charging uses electricity stored in the system during times when electricity prices are low, such as at night. It is estimated that the basic fee can be reduced by approximately 20-25% (several million yen) per year.

Of the 882 MK taxis licensed in Kyoto Prefecture (as of June 2026), 258 are EV taxis, making the EV conversion rate 29%. MK Holdings (HD), the group's holding company, aims to convert all its vehicles to electric vehicles by 2030, and it will be important to improve charging efficiency by introducing systems. After conducting demonstration tests at the head office, the plan is to install the system at sales offices and other locations.

Tatsuya Kanemoto, vice president of MK HD, said, ``I like everything for the first time, and this time we were able to install an advanced system.We hope that this system, which is safe and highly durable, will help solve energy problems and become an opportunity for its use in Japan.''