Posted 01.15.2016 in Articles
The argument that EVs powered from the grid aren't really any more eco-friendly than internal combustion engines burning fossil fuels continues to be debunked. Studies by the Union of Concerned Scientists, the University of Minnesota, and Carnegie Melon University all show EVs produce fewer emissions than gasoline-burning cars throughout the lifecycle.
The Union of Concerned Scientists study addressed the talking point used by EV skeptics that said an EV is only as clean as the power plant that charges its batteries. Since 45% of US electricity comes from coal, the assumption was an EV can actually be responsible for more greenhouse gas emissions than a fuel-efficient vehicle. According to the study titled, “State of Charge: Electric Vehicles’ Global Warming Emissions and Fuel-Cost Savings Across the US”: “Electric cars produce lower global warming emissions and cost significantly less to fuel than the average compact gasoline-powered vehicle.”
The University of Minnesota Study, titled “Life Cycle Air Quality Impacts of Conventional and Alternative Light-Duty Transportation in the United States” points out that EVs powered by coal burning power plants might not be the best answer to reducing carbon emissions, but they are a step in the right direction. The study also says EVs charged by power plants that use cleaner burning natural gas, nuclear and renewables are a much better option for reducing pollution. Although some opponents to EVs point to this study as evidence that EVs are not the best solution to reducing pollution fail to factor into their objections that the majority of EVs currently in use are located in areas within the US that get a majority of their power from cleaner burning power plants.
The Carnegie Melon study “Regional Variability and Uncertainty of Electric Vehicle Life Cycle CO2 Emissions Across the United States” compares the lifecycle carbon emissions of the (pure electric) Nissan LEAF to those of the (plug-in hybrid) Chevrolet Volt and Toyota Prius Plug-in. This study too points out that even though there are drastic regional differences between the amounts of coal used in the production of electricity, over an EV's entire life cycle, known as well-to-wheels, EVs produce less carbon pollution.
The evidence builds from there. Another Carnegie Mellon study finds battery electric vehicles powered with natural gas-based electricity emits 40% fewer green house gasses over its life cycle compared to a gasoline vehicle.
Another study, “Environmental Assessment of a Full Electric Transportation Portfolio,” produced by the Electric Power Research Institute (EPRI) and the Natural Resources Defense Council (NRDC), in September 2015 found that when “combining reductions from vehicle electrification, a cleaner electric sector, and existing programs that improve conventional vehicle efficiency, the modeled electricity and transportation sectors together achieve a 48% reduction in GHG emissions between 2015 and 2050 in the Base GHG scenario, and a 70% reduction in the Lower GHG scenario.” The report goes on to state that “While electric vehicles are cleaner than petroleum-fueled vehicles today, the greenhouse gas reductions can be maximized by charging vehicles from a cleaner grid. With a 62% share of light- and medium-duty vehicles in 2050, electric vehicles would consume 13% of grid-supplied electricity”
When looking at the evidence it is clear that EVs produce fewer carbon emissions even when powered by coal-fired power plants. What is often overlooked in these discussions is the fact that an EV can be fueled with energy from the sun, wind, geothermal or even tidal with zero emissions. And, with a home solar system, that energy can be had for free from a non-polluting, solid state system that requires no maintenance and lasts for at least 30 years. No matter what you do with an internal combustion vehicle, you're always burning fossil fuel.