Tesla says the 7MWh project makes it the biggest energy storage development in Asia, and like its giant Australian Powerpack system, it was completed with eye-watering speed — the hardware was apparently installed in just two days.

Osaka’s trains are some of the busiest in Japan, transporting millions of people every day, so Tesla’s Powerpack will undoubtedly prove a blessing during power interruptions. While the company’s energy division tends to take a backseat to its EV work, its 2018 figures show it’s playing an increasingly prominent role not only within the Tesla empire, but across the energy storage landscape in general. Last year the company deployed 1.04Gwh of energy storage, nearly triple the 358MWh rolled out in 2017.