An electric vehicle, or EV, is a vehicle propelled by electric motors. The motion may be provided either by wheels or propellers driven by rotary motors, or in the case of tracked vehicles, by linear motors. The electrical energy used to power the motors may be obtained from chemical energy stored on the vehicle in batteries; from a direct connection to land-based generation plants, as is common in electric trains; from nuclear energy, on nuclear submarines and aircraft carriers; or from more esoteric sources such as flywheels, wind and solar.
The reasons that electric motors are a good choice to drive vehicles are that they can be finely controlled, they deliver power efficiently and they are mechanically very simple. Electric motors often achieve 90% conversion efficiency over the full range of speeds and power output and can be precisely controlled. Electric motors can provide high torque while an EV is stopped, unlike internal combustion engines, and do not need gears to match power curves. This removes the need for gearboxes and torque convertors. Electric motors also have the ability to convert movement energy back into electricity, through regenerative braking. This can be used to reduce the wear on brake systems and reduce the total energy requirement of a typical trip.
Personal highway-capable EVs are driven by tens of thousands of people worldwide.
There are currently two types of electric car (and van) available; battery cell and hybrid. Battery cell cars are powered by simply plugging into any electrical mains outlet. This only costs 1p per mile, which obviously compares favourably to both petrol and diesel. Battery cell cars are currently the most commercially popular type of electric car at the moment. Hybrid vehicles are a combination of petrol and electric. The electric element of the car is used as an assist to the petrol engine, and runs the vehicle to speeds up to 6mph, after which the petrol takes over. This particular type of electric car is useful in city environments, where a lot of time is spent at lower speeds. It also eliminates emissions from slow moving traffic jams when the engine is kept running. A third, less established form, is the 'plug-in hybrid' which attempts to combine the benefits of both these designs. It allows the moderate capacity batteries of a hybrid vehicle to be recharged not only from the internal combustion engine and generator, but alternatively from an external source of electricity (such as a domestic electricity supply).
GO ELECTRIC
While electric cars can sometimes cost £5,500 more than conventional vehicles, according to the Energy Saving Trust (www.est.org.uk 020 7222 0101), they can cost as little as 1p a mile to run.
In addition, electric cars are not subject to road tax and, as an added bonus for London drivers, enjoy 100 per cent congestion charge discount. Drivers living in areas where residential parking demands paying for a permit might also find that they get a discount on this cost.
Electric cars use a battery and electric motor to power the vehicle meaning they have no emissions at the point of use.
Due to the capacity of the battery, their range is limited to about 60 miles or less between recharges, making them best suited for city-based users.
Electric vehicles can be recharged by plugging them into an existing electrical socket and some city councils are installing electric recharging points in car parks or on-street.
The G-Wiz model (www.goinggreen.co.uk) claims to consume just one quarter of the energy of a similar sized petrol car. The makers say it costs around £1.64 a day to run, equivalent to around 600 miles per gallon. The list price is £8,299, but it is currently on offer at £7,799 and orders for cars placed by 31 March come with free leather seats worth £499.
HYBRID CARS
Hybrid vehicles, such as the Toyota Prius, Honda Insight and Honda Civic IMA, run on a combination of a petrol engine and an electric motor powered by an energy storage device such as a battery pack.
All hybrids use regenerative braking, which means that energy is put back into the battery when braking. This improves energy efficiency and also reduces brake wear.
Hybrid technologies improve fuel efficiency and therefore provide considerable fuel savings compared with a normal petrol vehicle. While models might cost between £1,000-£3,000 more than conventional cars, running costs are two thirds that of equivalent petrol fuelled vehicles, according to the Energy Saving Trust.
Hybrids also benefit from reduced vehicle excise duty and do even better after the Budget. In addition they are exempted from the London congestion charge.
Data compiled by motor insurance company More Than has shown a dramatic increase in the popularity of eco-friendly vehicles. The research found that registrations of hybrid vehicles in 2005 were up by 74 per cent from 2004 levels.
Other findings suggest that one-in-six motorists in the UK would consider trading in their car for an electric or hybrid model if fuel prices continue to increase and that a billion hybrid vehicles would be running within 15 years. More Than's heads of motor insurance, David Pitt, welcomed the increasing popularity of 'green' cars.
"Given the growing concern about global warming it's encouraging that so many motorists are considering changing their driving habits....As awareness increases, I am sure we will see more innovation from the motoring industry, as well as incentives from the government to encourage motorists to become more eco-friendly."
Sources:
Green Consumer Guide
Wikipedia
Electric Vehicle UK |