car

How do electric vehicles work?

Nov 3, 2017 - 3min read



The best introduction to electric vehicles is to announce that they are astonishingly uncomplicated. Popular imagination conflates ‘electric car’ and ‘flux capacitor’ despite the fundamentals of this technology being, well, child’s play.

Simply put, a battery powers a motor that turns the wheels. It is as straightforward as a toy electric train. Though, admittedly, when Elon Musk builds an all-electric car that can go from 0-60mph in 2.5 seconds, it does become slightly more advanced.

“Electric cars release stored energy electrochemically.”

Fans of the DeLorean time machine need not be disappointed – this story too involves time travel. The first electric car was built in 1834 and in 1900 up to 34% of cars were electric. The movement stalled when Henry Ford – propped up by an abundance of low-cost oil – began to mass-produce petrol cars in 1908.

It is a case of ‘back to the future’ for the electric car, as they become increasingly popular in the UK and across the world. Earlier this month, Germany made headlines resolving to ban all combustion engine cars by 2030. So, we are here to explain everything you need to know.

EV

Let’s start with the basics: cars are powered by converting potential energy into kinetic energy. Petrol-powered cars burn fuel, releasing harmful gases into our environment while creating energy. Electric cars release stored energy electrochemically, meaning kinetic energy is produced by the electrons released as the battery slowly discharges. No burning fuel equals no pollution. 

Today, there are two types of fully electric cars: fuel cell vehicles and battery-powered cars.

Fuel cells combine hydrogen and oxygen to generate electricity. The only by-products in this conversion are water and heat – your car can literally brew a cuppa. Fuel cells are used by NASA to power their shuttles and the water produced keeps the astronauts hydrated.

Fuel cell vehicles are less efficient than battery-powered vehicles because they rely on hydrogen, the production of which emits noxious gases. Despite this, their emissions are some 30% lower than petrol-guzzling counterparts.

These cars are also more efficient in how they consume energy. Both battery and fuel-cell powered cars operate an ‘idle-off’ system where the engine stops when the brakes are engaged.

Like fuel-cell vehicles, battery-powered vehicles themselves produce no tailpipe emissions. When charged from renewable sources, they produce virtually no emissions at all.

“Battery-powered vehicles deliver the same torque at any moderate speed.” 

In addition to the incontrovertible environmental benefits, battery-powered cars are an exhilarating ride. Perhaps their futuristic reputation is perpetuated by the zooming feeling thanks to near-instant torque (turning force) ensuing extremely fast acceleration. As opposed to stepping on the gas for more power, battery-powered vehicles deliver the same torque at any moderate speed.  

These vehicles offer further advantage to drivers as they are so easy to maintain. By virtue of having fewer moving parts they suffer less wear and tear. Regenerative braking not only conserves energy but protects the brake pads from strain. This, and saving money on fuel, tots up to considerable savings.

A full charge – which typically takes 4 hours with a home charger, but as little as 30 minutes with rapid chargers provided at motorway service stations – delivers a driving range of 70 to 100 miles. Engineers are innovating solutions to make charging more convenient such as using drones – as Tonik MD Chris Russell explains in our Green Tech Briefing.

Exciting developments for car design are ceaseless. Tesla describes the dual motor model in their Model S as a ‘categorical improvement on conventional all-wheel drive systems’. With one motor in the front and another in the rear, it can digitally control torque in either axle independent of each other to produce amazing traction. That is not even to mention that the Model S can accelerate 0-60mph in just 2.5 seconds (the Lamborghini Huracán 610-4 managed 2.8). View Tesla's Winter challenge.

As Tesla is demonstrating, battery-powered cars are a serious business with the capacity to change the world. Driving forward, the mission will be to equip all cars with batteries powered by renewable sources.

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