Yet despite being the size of 22 soccer pitches, with an immense production capacity of 900MW, only 150 employees are on duty at any given time. The hard work is done by about 1,000 robotic machines whirring away in a surreal cacophony of hums, bleeps, bells and buzzers.

“I see seldom see people anywhere, just at break times,” says factory manager Kazuki Kakegawa as he shows Recharge around.