The Chinese bus company couldn’t work it out. Some days when its buses merely crawled along Shanghai’s streets, their power consumption would go through the roof. The reason why was a mystery. So, a team from the US firm Montana Technologies flew out to investigate. They started clamping electricity meters onto parts of the bus and soon realized what Yutong Bus, the Chinese company in question, had missed.“They didn’t instrument air conditioning,” says Matt Jore, CEO of Montana Technologies, exp...