Inventing electric cars is easy - now UK needs to reshape itself

When the automotive revolution kicked off at the beginning of the 20th century, the dominant technology wasn't petrol - it was electric.

The cars were slow, with a top speed of around 20mph, but - unlike petrol - they didn't smell, they didn't need gears and they didn't need starting with a hand crank.

For pottering around the city, they were unbeatable.

However, by the 1920s, they were in decline. Petrol became much cheaper and the road network expanded, meaning the limited range of electric cars became a problem.

The combustion engine took over - a lead it wouldn't relinquish until today.

Two companies, aided by governments around the world, have pushed the revival in electric: Toyota and Tesla.

The Toyota Prius made hybrid vehicles mainstream. Then Tesla terrified traditional automakers by fully embracing electric.

The breakthrough was batteries. As smartphones became more popular, the lithium-ion technology they use kept on improving. That could be applied to vehicles too.

Today, all manufacturers are competing to squeeze as much juice as possible from the battery.

The price of buying an electric vehicle will be the same as a petrol one from next year, according to analysts at UBS, and by 2024, one in three cars sold in Europe will be electric.

Morgan Stanley estimates electric car sales will overtake petrol globally by 2040 - meaning the UK Government's ban on the sale of petrol and diesel isn't as drastic as they'd like you to think.

But governments worldwide have been crucial to electric's growth.

California provided nearly $5bn (£3.8bn) in grants to Tesla while, across Europe, electric car sales have been driven by subsidies. When Denmark scrapped them in 2016, sales fell by 60%.

The European Union is also imposing tougher emissions standards from 2019.

Because they apply across a manufacturer's fleet, the easiest way for car-makers to meet the new rules is to produce all-electric vehicles.

With pretty much every manufacturer now committed to electric, no one country is clearly ahead of the game.

Electric cars are much simpler to make than petrol vehicles - they have fewer moving parts.

It's easier for new companies to set up - hence rumours Dyson and Apple, better known for vacuum cleaners and iPhones respectively, have both been working on cars.

It also means manufacturing can be specialised. BMW's all-electric Mini will be made in the UK, but its drivetrain will be made in Germany, then fitted here.

Then there's infrastructure for electric cars. The UK Government on Wednesday announced £100m of funding for car charging infrastructure. That's simply not enough.

Norway is the leader here - it has more electric car charging points than the UK, with a population more than 10 times smaller.

That makes a difference. In 2016, 40% of all cars sold in Norway were electric.

The Scandinavian country also leads the way in fast-charging technology: this year it opened a station that can charge 28 cars in half an hour - closer to the capacity needed to make electric cars work on a mass scale.

Britain's National Grid will also need modifying to deal with millions of electric vehicles charging overnight.

Demand could be as much as 8 gigawatts higher by 2030 - about the capacity of new nuclear power plant Hinkley Point C.

Inventing the electric car was the easy part. Reshaping our entire country's motor infrastructure around it will be much harder.