Electric Vehicles

ESBe-car Charging

An ESBe car charging up. Photographer: Ruth Collier

ESBe-car Charging

ESBe-car Charging

An ESBe car charging up. Photographer: Ruth Collier

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Electric vehicles are just one of the ways in which Europe can move towards more sustainable transport. Other key factors in increasing transport sustainability include further development of renewable biofuels, a move towards non-motorised and/or public transport, and changing the ways in which we use our transport systems.

Replacing conventional vehicles with electric vehicles can help reduce GHG emissions, although how much it helps depends significantly upon the source of electricity utilised to charge vehicles: renewable sources, nuclear power or fossil fuel. However, simply replacing conventional vehicles will not address other problems such as increasing congestion or growing demand for road infrastructure and parking. In the short and medium term, Europe will still need to rely on conventional road vehicles, while new and cleaner technologies advance (EEA, 2016).

How Electric Vehicles Work

Over the last decade, vehicle manufacturers have developed several alternative engine technologies. These include battery electric vehicles that include a number of specialised parts, including the battery, an electric motor, an engine controller and regenerative brakes. 'Hybrid' vehicles include all the same main parts as a battery electric vehicle, as well as having a conventional main or auxiliary combustion engine and associated fuel tank (EEA, 2016).

• Electric motor: An electric motor powers the vehicle using electrical energy stored in the battery. An electrical motor can also act as an on-board generator for the battery by producing electricity while the vehicle is decelerating. Electric motors have a number of advantages over conventional combustion engines, including higher efficiency (an electric vehicle converts approximately 80% of the energy it uses to usable power, in comparison to approximately 20% for a conventional vehicle), high durability, lower maintenance costs and reduced noise pollution at low speeds.
   
• Batteries: The battery in electric vehicles store electrical energy that the electric motor utilises to power the vehicle. Most electric vehicles use lithium‑ion batteries. These have a number of advantages over most other battery types, including higher energy storage capacity and longer lifespans. However, current battery systems tend to be both heavy and costly to produce. Furthermore, these batteries lose capacity over time as a result of ageing and repeated charging cycles. Developing improved battery technologies is therefore a major priority for further research and development at an EU level.
   
• Regenerative brakes: Regenerative brakes help to keep the battery in an electric vehicle charged, by converting much of the energy that would normally be lost as heat during braking into electricity. These systems include a small electrical generator as a component of the vehicle's braking systems; they must be used together with conventional friction-based brakes. One additional advantage of regenerative brakes, apart from enhancing the overall energy efficiency of the vehicle, is that they increase the life of the vehicle's braking system, as its parts do not wear out as quickly.