Using the national average of about 70% fossil-fuel-based electricity in a state’s energy mix, a PHEV has slightly more greenhouse gas emissions than an HEV. In states less reliant on fossil fuels for electricity, PHEVs pollute less than HEVs. In states more reliant on fossil fuel, PHEVs pollute far more than HEVs (see table below).
Because they are much more efficient users of energy—no matter the electricity source—EVs and PHEVs always have fewer greenhouse gas emissions compared to conventional gasoline vehicles. You can learn about your state’s carbon emissions at the Department of Energy’s Emissions from Hybrid and Plug-In Electric Vehicles website (http://bit.ly/AFAVDCemissions).
The Union of Concerned Scientists report, State of Charge: Electric Vehicles’ Global Warming Emissions and Fuel-Cost Savings Across the United States, found that EVs fueled from the dirtiest of utilities emit less CO2 than a new ICE compact car that averages 27 mpg. If powered by the cleanest grid, EVs beat the best HEV. If powered by wind- or solar-generated electricity, an EV will have no CO2 emissions.
This depends partly on how much you drive—the more you drive, the more you will save. It also depends on the initial purchase price of the EV or PHEV compared to an ICE vehicle. In general, the higher the upfront capital cost of a plug-in car, the lower the per-mile operating cost.
Cost recovery depends upon how much you paid for the vehicle’s “EV-ness.” To determine that, you must compare what you will pay for a PHEV or EV to the most similar ICE model. For example:
The generally useful Department of Energy’s vehicle cost calculator (bit.ly/AFDCcalc) uses the miles you drive and the cost of gasoline. But it bases its calculations on the regional average price of electricity, assumes maintenance costs per mile are the same for both EVs and ICE vehicles, and presumes a five-year car loan at 10% interest. If the calculator allowed users to change these parameters, it would be provide a more accurate result.
EVs and PHEVs qualify for up to $7,500 in federal income tax credits. Many states offer other incentives as well. For example, Californians can get a $2,500 rebate on qualifying vehicles; Oregonians can take an income tax credit equal to 25% of the cost of an at-home charging station ($750 maximum) or 35% of the cost of a business charging station. District of Columbia residents receive reduced registration fees for the first two years of the car’s ownership; plus, the sales tax is waived on the vehicle purchase. You may also be able to get time-of-use (TOU) utility pricing so you can coordinate recharging your vehicle when electricity demand (and rates) are low.
There are also private and utility incentives, including free at-home charging stations. The DOE’s Federal and State Incentives and Law website (bit.ly/AFDCincentive) can help you determine your eligibility. For example, in portions of California, you can take a state tax credit after installing a charging station at your home. San Diego Gas & Electric offers customers lower rates for EV charging.