Electric vehicles depend on batteries, which are still currently heavy and bulky and only enable a limited distance range to be travelled. Recent improvements in the distance range (now in excess of 250 miles), however, have led to an increase in interest in the use of this technology for van-based home deliveries (MacLeod, 2007) and other van-based operations. Smith Electric Vehicles, for instance, produce a range of smaller trucks (including a 9-t truck), where the batteries are stored on the underside of the truck. These are currently in use by a number of large UK companies. Although electric vehicles are not yet capable of powering larger trucks, there are many hybrid trucks on the road that combine electric and diesel power. Conventional axles can be replaced by electric-driven differential units that produce electricity to help power vehicles up hills and at the same time recharge the batteries when not in use. A growing number of vehicles also use regenerative braking systems that slow the vehicle and simultaneously recharge the battery.
For the freight industry, the attraction of electric vehicles is twofold. They are virtually pollution-free at point of use (emitting almost no tailpipe emissions), and they are much quieter than conventional goods vehicles (producing fewer vibrations). For these reasons they are eminently suitable for use within city environmental zones. On the cost front, they incur no vehicle excise duty (VED) and use no fuel (except electricity). However, the capital cost of the vehicles is considerably above that of conventional vehicles.
Electric vehicles have been in use for deliveries for decades, with the British milk-float being an early and enduring example. The technology is now fairly common in buses and considerable attention has been paid to introducing it into private cars. Academic studies have tended to focus on private transport up-take of this technology (Carlsson and Johansson-Stedmann, 2003; Delucchi and Lipman, 2001; Chan and Chan, 2001). As the pressure increases on logistics companies to become more environmentally friendly, interest in electrically powered goods vehicles looks likely to increase.
Environmentally, the benefit of electric vehicles is an almost total elimination of both tail-pipe emissions and engine noise. The problem remains, however, that batteries must be recharged using electricity and the production of the electricity itself is environmentally unfriendly; the extent of the damage done depends on the ultimate source of the electricity. Until electricity is produced from renewable resources, the burden of environmental damage is merely being transferred from the vehicle upstream to the electricity production process.
In terms of biodiesel, a 5 per cent reduction by volume is equivalent to a 4 per cent reduction by energy (DfT, 2008)