Electric vehicles (EVs) are commonly referred to as "zero emission vehicles", meaning they emit no criteria pollutants or greenhouse gas emissions during use. However, sourcing and distributing the electricity required to operate an EV generally results in significant emissions. Therefore, knowing how the electricity is created is important.
Electricity can be created from a number of resources, including coal, natural gas, petroleum, nuclear, hydro, solar, wind, biomass, and more. ACEEE's greenercars.org currently scores EVs and PHEVs based on the national average electricity generation mix. However, electricity generation is not uniform across the U.S. To account for these differences, ACEEE has developed a calculator that will help potential electric vehicle buyers and existing owners understand the true impact of EVs in their region. The calculator adjusts the national Green Score of an electric vehicle based on the difference between the national average grid mix and the grid mix in the chosen region. This regional grid mix is determined by the zip code entered into the spreadsheet. This zip code is also linked to local gasoline and electricity prices.
Note that the calculator thus far doesn’t account for when the chosen electric vehicle is charged during the day nor seasonal variations in the electrical grid. Nevertheless, we hope this is valuable tool for consumers. We welcome any feedback about how we can continue to improve this resource, so please feel free to contact us at the email address listed on our contact page with your ideas.