A recent study shows that charging your electric vehicle at night could help diminish harmful pollutants at the Earth’s surface. The study was conducted by the Massachusetts Institute of Technology (MIT) and the University of Texas and looked at different charging habits of electric vehicle (EV) drivers in four cities in Texas and how they affect levels of air pollutants. The researchers found that in addition to nighttime charging being more cost effective and reliable — less power being used means more, cheaper power for your car — it also decreases the levels of ground pollutants including ozone.
The research was conducted in the metro areas of Dallas/Ft. Worth, Houston, Austin and San Antonio where the electric grid is made up of roughly 46% gas, 35% coal, 13% nuclear and 4.5% wind power. The researchers made a model of the area supposing a future level of 20% electric vehicle owners and then calculated the grid emissions from various charging habits. The first scenario was charging at night, the second was charging whenever it was convenient and the third was charging just before a trip and only as much as you need.
It was found that all three scenarios — at a 20% population level — created lower emissions than the equivalent amount of gasoline. The researchers also discovered that charging at night released a much lower amount of pollutants into the atmosphere, most notably those that create ground level ozone. The pollutants that are released by the grid during the night generally dissipate before morning, making them less harmful. Ground level ozone is quite harmful to the respiratory systems of humans and animals and can be hugely damaging to plant life. The researchers hope their study will lead to a push towards developing policy that will encourage nighttime charging. “As more of the fleet switches over to PHEVs and a larger demand is placed on the electricity grid, it will become more important that we design and implement policy that will encourage charging behaviors that are positive for both air quality and grid reliability,” said lead author of the study Dr. Tammy Thompson of MIT.
Via Red Orbit