From NCPA

Electric cars could produce higher emissions over their lifetimes than petrol equivalents because of the energy consumed in making their batteries, a study has found, reports the Australian.

• An electric car owner would have to drive at least 129,000 kilometers (about 80,157 miles) before producing a net saving in carbon dioxide (CO2).
• Many electric cars will not travel that far in their lifetime because they typically have a range of less than 145 kilometers (about 90 miles) on a single charge and are unsuitable for long trips.
• Even those driven 160,000 kilometers (about 99,419 miles) would save only about a ton of CO2 over their lifetimes.

The study was commissioned by the Low Carbon Vehicle Partnership, which is jointly funded by the British government and the car industry.

• It found that a mid-size electric car would produce 23.1 tons of CO2 over its lifetime, compared with 24 tons for a similar petrol car.
• Emissions from manufacturing electric cars are at least 50 percent higher because batteries are made from materials such as lithium, copper and refined silicon, which require much energy to be processed.

Many electric cars are expected to need a replacement battery after a few years.

• Once the emissions from producing the second battery are added in, the total CO2 from producing an electric car rises to 12.6 tons, compared with 5.6 tons for a petrol car.
• Disposal also produces double the emissions because of the energy consumed in recovering and recycling metals in the battery.

Source: Ben Webster, "Electric Cars May Not Be So Green After All, says British Study," Australian, June 10, 2011. Jane Patterson, Marcus Alexander and Adam Gurr, "Preparing for a Life Cycle CO2 Measure," Low Carbon Vehicle Partnership, May 20, 2011.

For text:  http://www.theaustralian.com.au/news/health-science/electric-cars-may-not-be-so-green-after-all-says-british-study/story-e6frg8y6-1226073103576

For study:  http://www.lowcvp.org.uk/assets/reports/RD11_124801_4%20-%20LowCVP%20-%20Life%20Cycle%20CO2%20Measure%20-%20Final%20Report.pdf