Electric car:
An electric car is a plug-in battery powered auto mobile which is propelled by electric motor(s). Electric cars were popular in the late-19th century and early 20th century.
However, advances in internal combustion engine technology and mass production of cheaper gasoline vehicles led to a decline in the use of electric drive vehicles. Electric
cars have several potential benefits as compared to conventional internal combustion auto mobiles that include a significant reduction of urban air pollution as they do not emit
harmful tailpipe pollutants from the onboard source of power at the point of operation.
- Batteries:
Finding the economic balance of range against performance, energy density, and accumulator type versus cost challenges every Electric Car manufacturer.
While most current highway-speed electric vehicle designs focus on lithium-ion and other lithium-based variants a variety of alternative batteries can also be used. Lithium based batteries are often chosen for their high power and energy density but have a limited shelf-life and cycle lifetime which can significantly increase the running costs of the vehicle. Variants such as Lithium iron phosphate and Lithium-titanate attempt to solve the durability issues with traditional lithium-ion batteries.
Other battery technologies include:
- Lead acid batteries are still the most used form of power for most of the electric vehicles used today. The initial construction costs are significantly lower than for other battery types, and while power output to weight is poorer than other designs, range and power can be easily added by increasing the number of batteries.
- NiCd - Largely superseded by NiMH
- Nickel metal hydride (NiMH)
- Nickel iron battery - Known for its comparatively long lifetime and low power density
Several battery technologies are also in development such as:
- Zinc-air battery
- Molten salt battery
- Zinc-bromine flow batteries or Vanadium redox batteries can be refilled, instead of recharged, saving time. The depleted electrolyte can be recharged at the point of exchange, or taken away to a remote station.
- History:
The energy crisis of 1970 - 1980 brought about renewed interest in the use of electric cars. In the early 1990s, the California Air Resources Board (CARB) began a push for more fuel-efficient, lower-gas-emissions vehicles, with the ultimate goal being a move to zero-gas-emissions vehicles such as electric vehicles. The global economic recession in the late 2000s led to increased calls for auto-makers to abandon fuel-inefficient cars, such as big American SUV's. California electric car maker Tesla Motors began development in 2004 on the Tesla Roadster, which was first delivered to customers in 2008. As of January 2011 Tesla had produced more than 1,500 Roadsters sold in at least 31 countries.
Retail customer deliveries of the Nissan Leaf in Japan and the United States began in December 2010, though initial availability is restricted to a few launch markets and in limited quantities. As of January 2011 other electric auto mobiles and city cars available in some markets included the Th!nk City, REVAi, Buddy, Citroën C1 ev'ie, and several neighbourhood electric vehicles. - Pollution:
Electric cars produce no pollution at the tailpipe which will contribute to cleaner air in cities, but their use increases demand for electricity generation. The amount of carbon dioxide emitted depends on the emission intensity of the power source used to charge the vehicle, the efficiency of the said vehicle and the energy wasted in the charging process.
For mains electricity the emission intensity varies significantly per country and within a particular country it will vary depending on demand, the availability of renewable sources and the efficiency of the fossil fuel-based generation used at a given time. Charging a vehicle using off-grid renewable energy yields very low carbon intensity.
An Electric Vcar recharged from the existing US grid electricity emits about 115 grams of CO2 per kilometer driven and a conventional US-market gasoline powered car emits 250g of CO2 per kilometer. According to official British government testing, the most efficient European market cars are well below 115g of CO2 per kilometer driven. Although a study in Scotland gave 149.5g of CO2/km as the average for new cars in the UK. In a worst case scenario where incremental electricity demand would be met exclusively with coal. In France, which has a clean energy grid, CO2 emissions from electric car use would be about 12g per kilometer.
A study done in the UK in 2008 has concluded that electric vehicles have the potential to cut down carbon dioxide and greenhouse gas emissions by at least 40% even when taking into account the emissions of current electricity generation in the UK and emissions relating to the production and disposal of electric vehicles.