The concept of Electric Vehicles (EVs) is not new. Experimental electric carriages were being built as early as the 1830s and many variations have appeared since, but they have never equalled internal combustion vehicles in popularity. However, concerns for the environment are now making EVs seem more attractive because they are non-polluting in use, and where opportunities exist locally to recharge them from a renewable energy source, they use no fossil fuel.
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Early EVs
During the 1830s and 40s, inventors in different continents were working on developing electric road vehicles. These included Robert Anderson and Robert Davidson in Scotland, Professor Stratingh of the Netherlands and his assistant, the German-born Christopher Becker, and Thomas Davenport in the USA. All these vehicles are believed to have used nonrechargable cells.
Subsequently, two French inventors, Gaston Plante and Camille Faure, worked to develop a storage battery that could be used in a vehicle. A three-wheeled electric car designed by the French inventor Gustave Trouvé was demonstrated at the International Exhibition of Electricity in Paris in 1881, and for the rest of the century engineers in France and Britain continued to improve electric vehicle technology. An electric racing car called La Jamais Contente, designed by Camille Jenatzy and built in Belgium, set a world land speed record of 68 mph in 1899.
Despite their early promise, electric vehicles were rapidly overtaken in popularity by petrol-driven cars in the first part of the 20th century, when little was known about the effects of fossil fuel consumption on the environment.
Characteristics of EVs
Quite apart from the fact that they produce no exhaust fumes, electric vehicles have certain other inherent advantages. When the power from an internal combustion engine is transmitted to the wheels, some system of variable gearing is needed because torque is so low at low revolutions. Electric motors can deliver high torque at low revs, so no gears are necessary. This makes for easy driving and smooth, fast acceleration. EVs are also far quieter than petrol or diesel vehicles.
The other side of the coin is that batteries can only store a finite quantity of energy; once this is exhausted the vehicle will stop, and it will take several hours to recharge the battery. Until recently, the distance that an EV could travel before it required recharging was relatively short (though it is reported that in the early days of road transport, EVs could travel further between charges than steam vehicles could between refills). A second disadvantage when compared to the internal combustion engine is that a heavy-duty electric battery pack is far heavier than a tank of fuel.
Recent Developments
Interest in developing EVs for city use revived in the 1960s when the volume of traffic on the roads was causing serious delays and frustration to motorists; traffic pollution was also seen as a problem, but the full environmental implications of high levels of CO2 in the atmosphere were not widely understood at that stage. A number of EVs were trialled and some were marketed, but these models remained a rare sight on the roads.
The new generation of EVs is gaining more favour amongst city drivers. Their use is encouraged by the UK vehicle taxation system, and London and some other places already have a network of charging points for EVs; the Orkney island of Westray, which has its sights set on becoming a 100 per cent renewable energy island, provides charging points that supply electricity generated by wind power. The range of vehicles available in the UK includes small cars for private motorists, specialist vehicles for municipal use, and trucks for on-site or local freight transport. Lithium-ion batteries are now being used because their performance does not deteriorate after repeated charging, and the latest EVs are capable of travelling 100 miles or more between charges, at speeds of over 60 mph.
Environmental Credentials
With zero tailpipe emissions, EVs cause no damage to the environment whilst travelling. If ‘green’ electricity is used to recharge them their entire cycle of use will be carbon-free; this will not be the case if they are plugged into a fossil-fuel electricity supply for around four hours at a time, but their impact on the environment per mile will still be minimal in comparison to many other road vehicles.
The manufacturers of EVs are also focusing strongly on using non-polluting production processes and clean recyclable materials. If or when EVs are able to travel further between recharges, with guaranteed access to clean, efficiently-generated electricity, we could be very close to having a quiet, economical, non-polluting form of transport; CO2 emissions from road traffic will reduce, climate change could be slowed, and the difference in air quality in cities around the world could be tremendous.
