Electricity is not a source of energy, cont.:

This study, conducted by the Argonne National Laboratory and China's Tsinghua University, specifically focuses on China and concludes that mass [Electric Vehicle] adoption could lead to tremendously higher emissions of carbon dioxide, nitrogen oxide and sulfur dioxide due to the country's widespread use of coal as a power source.

Here's the skinny from the study:

• China currently utilizes Euro III emission standards throughout much of the nation, though Euro IV is in use in some larger cities and will slowly replace the older standard within ten years. If charged by the current coal-heavy electrical mix displayed in the table above, EVs would double the nitrogen oxide emissions of Euro III gasoline vehicles.
  
• EVs will not reduce carbon dioxide emissions in China unless coal technologies are improved upon or a shift towards cleaner power generation occurs in the future.
  
• Mass adoption of EVs in China will cause sulfur dioxide emissions to increase by three to ten times the current level. Even advanced technologies such as coal washing cannot reduce sulfur dioxide emissions of EVs down to gasoline-powered vehicle levels.