The EVolution #9: True Grid
Does your state produce "clean" or "dirty" electricity?
When I first started working in the EV space, I was good-naturedly pressed by a few friends and family members about whether electric cars can actually make a difference in combating climate change. Most def, I was happy to tell them. I’d only recently become acutely aware that “the transportation sector generates the largest share of greenhouse gas emissions” in the U.S.
Even so, one might think that pollution in transportation largely comes from industrial and commercial usage (e.g. big rigs, ships, and planes). Not so!
The largest sources of transportation-related greenhouse gas emissions include passenger cars, medium- and heavy-duty trucks, and light-duty trucks, including sport utility vehicles, pickup trucks, and minivans. These sources account for over half of the emissions from the transportation sector.
I previously covered how electric vehicles are far more energy-efficient than internal combustion engines. They also produce no emissions as they drive. However, the production of the electricity that powers their batteries can cause pollution—potentially a substantial amount. In fact, after the transportation sector, the leading source of GHG emissions in the U.S. is electricity generation!
How we get electricity matters a lot, and this has evolved over the past decade. Different parts of the country rely on different sources for electricity: fossil fuels like coal and gas; renewable energy like wind, solar, and hydro; and nuclear energy (still responsible for producing nearly 20% of power in the U.S.).
These different sources have different levels of impact on greenhouse gas emissions, including carbon dioxide (CO2), in focus with regards to climate change. And, as we’ll see below, even when a region generates a relatively high share of its electricity from wind or solar, those positive effects can be dwarfed by the impact from fossil fuels, particularly coal.
How clean is the grid?
Earlier this year, the EPA released “eGRID 2019” data on electricity production, source types, and associated pollution by region and by state. I’ve analyzed the data and created some publicly available Tableau visualizations illustrating each state’s sources of, and contribution to, net power generation, as well as their average rates of associated CO2 emissions.
Not “King Coal”
From these infographics, there are some key observations:
Five states (TX, FL, PA, CA, and IL) produce nearly a third of the country’s electricity. “Everything is bigger in Texas”—they’re by far the #1 state in power generation (which is why the ERCOT blackouts earlier this year were such a big deal)
The seven states with the highest share of power generated from renewable energy sources are spread across the country: VT, ME, ID, SD, WA, OR, and CA. Combined, though, they only make up 10% of the country’s electricity supply; all have CO2 emission rates from power generation far below the national average
Some states with an above-average rate of power from renewables nonetheless have a relatively “dirty” grid: Montana, North Dakota, and Nebraska all rely on coal for a majority of their power, while Colorado and New Mexico both have significant wind contributions dwarfed by a combo of coal and gas
The states with the highest rate of CO2 pollution in their electricity production are all dependent on coal: Wyoming (84% from coal), West Virginia (91%), and Kentucky (72%)
There’s much to gain from the U.S. shifting toward more renewable energy, in more forms across the country. Numerous positive examples have already been realized. 70% of Idaho and South Dakota’s electricity production comes from a combo of hydro and wind power. 40% of Kansas’ production, and over a third of Oklahoma’s, comes from wind. 40% of California’s production comes from a mix of hydro, solar, and wind—and most importantly, virtually none from coal.
One thing I think about a lot is the marginal source of a kilowatt-hour. Even if your grid is 90% solar/wind, and 10% coal, if it's the coal that is scaled up or down with demand, then every use of electricity is using coal power and the reduction of any use of electricity is going to reduce coal burning. Agree with you anyway that electric cars are better than gas cars for the trips that remain necessary.