American regulators have proposed rules that will force electric vehicles into the Californian mainstream.

By 2018 81,000 clean vehicles could be on Californian roads, which is 5.5% of new cars sold. This includes vehicles which run at least 35 miles without producing emissions, such as hybrids, and pure zero-emission vehicles.

Currently vehicles produce 40% of the state’s greenhouse gases as well as a high percentage of other pollutants. With state law requiring California to cut emissions of greenhouse gases to 1990 levels by 2020 regulators are shifting their focus to cars.

Mary Nichols, Chair of the Air Resources Board said: “Most important for Californians, from an air quality perspective, is still the cars. After all these years, it’s still the cars.”

Speaking at the Reuters Global Energy and Climate Summit in San Francisco , regulators announced plans to let polluters trade the right to emit, which they believe would create a race to find the most effective way to cut carbon emissions, and to vastly increase solar power and wind generation.