Electric vehicles are far more efficient than cars powered by internal combustion engines. According to the Office of Energy Efficiency and Renewable Energy of the United States Department of Energy, electric vehicles convert between 59 and 62 percent of electrical energy on the grid into energy at the wheel, while conventional gasoline vehicles only convert 17 to 21% of the energy stored in gasoline into energy in wheels. This means that electric vehicles can dramatically reduce fuel costs due to their high efficiency. Miles per gallon gas equivalent (MPGe) and kilowatt-hours (kWh) per 100 miles are common metrics used to measure the fuel economy of electric vehicles.
Depending on how they are driven, current light-weight fully electric vehicles (or PHEVs in electric mode) can exceed 130 MPGe and travel 100 miles consuming only 25 to 40 kWh. The use of minerals such as lithium, cobalt and nickel, which are crucial for modern electric vehicle batteries, requires the use of fossil fuels to extract those materials and heat them to high temperatures. As a result, building the 80 kWh lithium-ion battery found in a Tesla Model 3 generates between 2.5 and 16 metric tons of CO2 (the exact amount depends largely on the energy source used to heat). When researchers used the average carbon intensity of the American power grid, they found that an all-electric vehicle emits approximately 25 percent less carbon than a comparable hybrid car.
But if they calculated the figures assuming that the electric vehicle would be charged in the state of Washington, with a lot of hydroelectric energy, they found that it would emit 61 percent less carbon than the hybrid. When they did the calculations for West Virginia, with a lot of carbon, the electric vehicle actually generated more carbon emissions than the hybrid, but even less than the gasoline car. In fact, it's hard to find a comparison where electric vehicles perform worse than internal combustion vehicles. Even when researchers calculated a comparison where electric vehicles lasted only 90,000 miles on the road instead of 180,000 miles, they were still 15 percent better than a hybrid car and much better than a gas-powered car.
To safely supply power from the electricity grid to a vehicle's battery, a charging station is needed, sometimes referred to as electric vehicle supply equipment (EVSE). Advanced electric vehicle batteries are designed to extend their lifespan, but will eventually wear out. In geographical areas that use relatively low-polluting energy sources for electricity production, electric vehicles tend to have an advantage in terms of lifecycle emissions over similar conventional vehicles that run on gasoline or diesel. Battery electric cars may not emit greenhouse gases through their exhaust pipes, but some emissions are created in the process of building and charging vehicles.
Without spark plugs to replace or oil to change, electric vehicles have a clear advantage over maintenance costs. The federal tax credit for motor vehicles with plug-in electric drives is available for the purchase of electric vehicles from manufacturers that have not yet met certain vehicle sales thresholds. The result is that electric cars are driving the transition to a more sustainable energy grid.