On Wednesday, Tesla announced that it had installed a bank of 42 Powerpacks at a train station in Osaka to service the Kintetsu Railway during the summer or in the event of an emergency.

The electric railway encompasses 311 miles of track powered by overhead lines and third rails. In its “disaster preparedness” capacity, the Tesla batteries will provide emergency backup power in the event of a blackout, providing a short burst of electricity to move any trains that might be stalled in tunnels or under bridges to safety.

The system is small—it has a little more than 7 megawatt-hours (MWh) of capacity and delivers 4.2 megawatts (MW) of power at one time. That’s enough to power stranded trains on Kintetsu’s track for just under a half an hour in an emergency.

It’s also not impervious to system-specific destruction: the Powerpacks are all located at one site, so if some overhead lines are toppled in an earthquake, there’s a chance that the trains may not receive this backup power. Still, the setup would help deliver train riders to safety in many disaster situations.

In non-emergency situations, Kintetsu hopes to use the Powerpacks to reduce electricity costs on hot summer days. When the nation’s electric grid is working overtime to power air conditioners during peak afternoon hours, electricity prices go up. If Kintetsu can replace some of that grid-delivered power with stored power from its Powerpacks, the railway will be able to save some money.

Tesla says this is its fourth-biggest installation in the Asia-Pacific region, notably following the largest lithium-ion battery installation in the world: a 100MW/129MWh battery located in Hornsdale, South Australia. But while lithium-ion battery prices are falling, they’re still expensive compared to generators and other forms of electricity. The exception has proven to exist in small applications like Kintetsu’s or in Belgium’s 18.2MW/21.7MWh Tarhills battery, which provides small amounts of instantaneous electricity to the grid to manage frequency response.

Listing image by Tesla

https://arstechnica.com/?p=1482005