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Not so long ago, the idea of running an electric vehicle as a viable concern would have been laughed out of the car park, with the road transport industry's continuing reliance on diesel pretty much unshakeable.
However carbon emissions are no longer an issue reserved for those with a leaning to the left – and as the public's awareness of the planet's woes continues to grow, companies increasingly need to be adapt (and be seen to adapt) to this change in thinking by employing less polluting vehicles.
This also means that companies keen to advertise their 'green' credentials are now actively seeking out operators that will match their environmental ambitions.
But it's not just about image. Electric-powered vehicles not only make you look good, they can save money in fuel costs when used in the correct application.
Add to this the fact they don't need an O-licence, require no road tax and are exempt from congestion charge (over £2,000 a year) and their appeal begins to broaden.
Modec's 5.5-tonner has been taken up by the likes
of Tesco, UPS and Hildon Water for urban delivery
work. It has a range of up 120 miles (depending on
battery type) and a payload of two tonnes.
Electric vehicles rely on onboard battery power and so are limited in their range - which is generally around 70-120 miles.
The batteries also need to be charged on a daily (or nightly) basis to ensure maximum running time the next day.
Battery technology is continually developing to provide greater range and smaller dimensions (certain battery packs can weigh up to a tonne).
Until recently, the main type of battery used was sodium-nickel chloride, or Zebra as it's also known.
This provides high power (five times more than traditional lead acid), while cycle life is up to 1,000 full charges.
However, it needs to operate at a very high temperature (270C) as well as using up to 14% of its power maintaining this level of heat, it always needs to have a charge in it to avoid complete temperature drop.
Although it is still used by several manufacturers, the sodium-nickel chloride battery is being slowly replaced by lithium-ion technology, which has a higher energy density and lower self-discharge as it doesn't need to maintain a significant heat level.
This allows for a longer range on the same-sized battery, as well as a reduction in size.
It's also less complicated in its makeup than Zebra technology (read reliability).
As an example, the Modec electric vehicle has recently moved from sodium-nickel chloride to lithium-ion technology, with an increase in range from 70 to 120 miles on a full charge.
The next stage in battery evolution is set to be lithium polymer, as used in mobile phones and laptop computers.
Currently under development, it's expected to become available late 2009 and will offer considerable benefits in size and range.
Don Newton, group technical director at Axeon, which supplies battery technology to Modec, says: "Over the next three to five years, battery technology will keep advancing at a steady rate, with a 5-7% improvement each year. We are currently working on lithium polymer technology, with the results potentially in production by late next year."
It's estimated that up to 30% of energy is lost through heat energy dissipation when braking, and many electric-powered CVs use a regenerative braking system to recover some of that energy.
It is channelled back into the main battery (or, if a hybrid electric/combustion engine set-up, into a storage battery) to be used for propulsion.
This system is particularly useful when applied in an urban delivery role, when constant stop/starting is common.
As the driver applies the brakes, the electric motors reverse direction the torque created by this reversal counteracts the forward momentum and eventually stops the vehicle.
Whenever the electric motor begins to reverse direction, it becomes an electric generator or dynamo, and feeds energy back into the battery.
Running an electric vehicle demands some changes in operation over the standard diesel arrangement, with the most significant being the need to charge it daily to maintain optimum power.
Most electric vehicles require an industrial-strength three-phase charging point, which has to be professionally installed then you need somewhere secure to leave the vehicle overnight.
As previously mentioned, range is also an issue.
Smith Electric Vehicles has three models on the
market. Two are based on current Fords (Transit
and Connect); the larger 7.5-tonner is based on
Avia's D75, and has proven popular with TNT.
Whether an electric vehicle is based on an existing diesel CV or a purpose-built example, it will be equipped with a battery of significant size, and more relevantly, cost.
Battery technology does not come cheap, adding tens of thousands of pounds to the cost of the vehicle and leading to an inflated list price – the payoff partly being the price of electricity when compared with diesel.
However this does depend on the current price of diesel – the tipping point for electricity is said to be when diesel is over £1.55/litre.
Also in the favour of electric vehicles is that they don't require an O-licence or road tax, and are exempt from the congestion charge (CC) where relevant.
The last point can make a significant difference. If a standard vehicle enters a CC zone every weekday for a year, the total cost is more than £2,000. Multiply this over six to eight years and the vehicle cost can start to look more appealing.
All these factors need careful consideration if electric vehicles are to work in your favour.
And finally there's the issue of residuals. Since electric vehicles are relatively new and current battery technology has not been proven over a vehicle's lifecycle (up to eight years), there are conflicting opinions over the residual value, with no monitoring organisations committing to figures.
Reed Business Information Limited.©2009
