|This section provides a general overview of Electric Vehicles (EVs), explaining what they are and how they work.
In addition, we take a look at the main performance parameters of EVs in comparison to traditional, petrol-powered vehicles. This way we explain why Electric Vehicles are the most environmentally friendly means of individual motorized transport available today.
|Most electric vehicles for personal transport are powered by batteries as an energy source (other sources include hydrogen and solar panels, but won't be feasible for practical purposes for many years to come)|
|The main categories of EVs for individual transport are cars, scooters and bikes|
|Compared to traditional fuel powered vehicles, EVs have a much lower impact on the environment: EVs emit only 30% of the emissions of a petrol powered vehicle, even when including the emissions incurred at the electricity power plant.|
|Emissions can be reduced to almost zero if the EV is powered by electricity produced from renewable sources such as solar or wind energy.|
|Operating costs are very low due to the low cost of electric energy with respect to fuel: energy for a year worth of driving costs around Euro 75-100.|
|While the acquisition cost of EVs is higher than that of comparable vehicles, EV prices are expected to decrease in the near future thanks to advances in technology (mainly batteries), increased economies of scale and competition|
On this site, we usually refer to Battery-Electric Vehicles (BEVs) when speaking of electric vehicles, also called all-electric vehicles. That is, vehicles which are powered exclusively by energy stored in batteries.
Most battery powered electric vehicles in production today have ranges of about 40-60 miles per charge, with top speeds of around 50-60 mph. While this means that they cannot fully replace traditional vehicles yet, EVs are well suited for inner city environments. In the vast majority of cases, the performance of EVs is fully sufficient for city use, where their lack of polluting emissions and noise is of particular advantage.
The performance parameters of EVs depend critically on the employed battery technology. These range from traditional and still widely-employed lead-based batteries which have been around for more than 100 years to more advanced (and expensive) nickel-based technologies.
Recently, also Lithium-based technologies have been introduced to electric vehicles (having been available in laptops and mobile phones for several years now). These enable better performances in terms of range and speed of the vehicle, but are also expensive -- prices will decrease however in the future.
Scientists are currently working on advanced battery technologies. Employing nanotechnology, they aim to significantly increase the energy storage capacity (yielding well over 200 miles range) and at the same time reduce the deterioration of storage capacity over time. This will eradicate a major drawback of current batteries, which in most cases have to be replaced during the lifetime of the vehicle due to capacity deterioration.
Most batteries used for EVs can be recharged in about 4 to 8 hours. Many owners conveniently recharge their vehicles over night or while at work. High performance recharging units are available from certain manufacturers. These can recharge an entire battery pack in 10-15 minutes using very high currents. However, these units are expensive and thus in most cases only suitable for fleet operators. Hopefully, they will eventually be available at public charging stations, too.
With respect to traditional, petrol powered vehicles, battery electric vehicles have a much higher energy efficiency. This means less energy consumed per driven mile and less greenhouse gases.
It is important to understand that EVs are not merely moving the emissions from the road to the power plants. In fact, they produce significantly less emissions overall:
On a tailpipe level (i.e., vehicle emissions during driving), battery electric vehicles yield zero emissions. However, to assess the full impact on the environment, one has to take into account the emissions at the power plant as well as losses incurring during the transport of electricity from the plant to the vehicle. This is the so-called well-to-wheel view. The result is that electric vehicles reduce CO2 emissions by upwards of 70% per mile driven with respect to the most efficient internal combustion engine equipped vehicles available (source: Tesla Motors and AVERE - European EV Association; for more info see the Resources section). Electric power plants operate much more efficiently than small combustion engines, which work efficiently only in a very narrow rpm band. In addition, most trips in cities are short in nature and characterised by a lot of stop-and-go. In other words, the engine often doesn't reach its ideal operating temperature, and often runs inefficiently. This is tantamount to a high level of emissions.
EVs have a far superior energy efficiency vs. traditional vehicles. Electric motors transform more than 90% of energy input into propulsion, with respect to only 40%-50% for combustion engines. Electric motors also have very high torque, which remains at a constantly high level throughout almost the entire rpm band. This in turn leads to acceleration capabilities which would let most other cars only see the EV's tailpipe - if they had one!
With an increase in energy produced from renewable sources (e.g. wind, solar, water, biomass) across the country, the level of reduced emissions from EVs can increase significantly. If the vehicle is charged with electricity gained exclusively from renewable sources, the emissions are near zero on a well-to-wheel basis.
Note that the well-to-wheel view is usually not applied to petrol powered vehicles. I.e., if the energy consumed in producing (and transporting) gasoline from crude oil was to be taken into account, the equation would yield even more advantageous results for EVs.
More information on this topic can be found in the resources section of this website.
At the same time, the cost per mile driven of a battery electric vehicle is a fraction of what it would be for petrol powered vehicles. Some of the current production electric vehicles yield a "performance" of ca. 2 to 3 Euro cent per mile. Considering an average yearly usage of 5000 miles, this translates into Euro 75 - 100 per annum -- little more than the cost of an average fuel tank in some of today's petrol powered compact cars.
In addition to this, EVs have far less moving parts than traditional vehicles, due to the absence of an internal combustion engine with its pistons, valves, oil pump etc. Electric motors are usually brushless today and thus require no maintenance at all. The same goes for the batteries, which require only little or no regular maintenance (topping up of water).
The major lifecycle cost driver of EVs are the batteries, the performance of which deteriorates over time. Usually, battery packs have to be replaced after anywhere from 2 to 8 years (depending on vehicle usage, charging modes, ambient temperatures, etc.).
In several countries (and sometimes cities), there are additional advantages from driving a battery electric vehicle.
|Congestion charge exemption (currently £8 in London per day upon entering the central area of the city). Road tax exemption and free parking and free charging in some areas.|
|EVs are exempt from taxes, benefit from free parking, pass toll roads for free, and are allowed to drive in bus lanes.|
|Up to Euro 2000 incentive for the acquisition of a new EV and a 5-year road tax exemption, reduced insurance rates.|
|In the US, most purpose built compact electric cars are classified as Neighbourhood Electric Vehicles (NEV) or Low-Speed Vehicles (LEVs).
NEVs don't have to comply with the normal regulations for cars, but are limited in maximum speed (25 mph) and the areas where they can be driven (urban core streets with speed limits up to 35 mph).
After all the good news, here is the catch. That is, if one considers only the acquisition cost, battery electric vehicles are still relatively expensive compared to traditional vehicles. That is mainly due to three factors: cost of the battery pack (which can reach several thousand Euros for lead or nickel based types, and more than Euros 10K for Lithium batteries), lack of economies of scale in manufacturing of vehicles (very small sales numbers compared to traditional vehicles), and, generally, lack of strong competition in this market (very limited number of manufacturers with small output).
However, considering the nature of these factors, it is to be expected that prices of EVs will decrease in the near future, as they are becoming more attractive to consumers and battery prices decline.
Also, considering the lifecycle cost of EVs, in particular the low operating expenditure, already today the higher acquisition cost can in many cases be easily offset over the lifetime of the vehicle.