“YOU SHOULD ALWAYS LISTEN TO PESSIMISTIC ENGINEERS”

I get suspicious when engineers say something can’t be done. They usually underestimate their own cleverness.

For example, I just found an article in an engineering magazine from 2 0 1 0 . It said to get a 4 0 0 -mile electric car, we’d need a battery larger than a Ford Focus, costing

£ 1 0 0 ,0 0 0 . It would have a life of two years. This was the era of the Mitsubishi i-MiEV. Yup, many engineers thought that little electric pioneer was the best we’d ever get.

Now it’s true we don’t have a reasonably priced 4 0 0 -mile electric car yet, but I think we can all agree it’s coming soon, and it’ll have a usable life of more like 20 years.

Most EVs get a facelift every three or four years, and at the same time their range improves by roughly 50 per cent. It happened to the Zoe, the Leaf and the i3. In other words, a battery that has one-anda-half times the capacity of the original. But which fits in the original space. And costs the same. And is just as robust.

This trend might continue, but actually we’re at the point where a 300-mile battery is feasible. So the focus of development is shifting. The cost has to keep dropping. That means less cost in terms of energy to build it, and also a smaller quantity of expensive minerals. Both those cost pressures help the environment too.

I’m not saying that engineers always overcome pessimism. It now looks unlikely we’ll get solid-state batteries until after 2025. Other transformative tech is even harder. But when it’s about gradually improving a known technology such as lithium-ion batteries, the engineers often surprise themselves.