From gold to uranium, resource extraction has often motivated theft of Indigenous peoples' lands. Now, increasing demand for lithium, managanese, and other materials needed for electrification has the potential to drive further attacks on territorial rights.
https://www.nature.com/articles/s41893-022-00994-6
Offshore wind farms have a lot of advantages. They don't affect existing land-based communities, and many wind resources happen to be located offshore. But researchers are just beginning to understand their impact on the marine ecosystem. https://www.nature.com/articles/s43247-022-00625-0
Which is not to say that critics of wind farms are necessarily concerned about the environment. In the US, the Texas Public Policy Foundation, funded by several fossil fuel companies, is a major force in anti-renewable advocacy.
https://www.nytimes.com/2022/12/04/climate/texas-public-policy-foundation-climate-change.html
Some sources point to the environmental impact of lithium mining, others observe that an electric vehicle might ultimately get its power from a coal-burning plant. While not all of these questions are asked in good faith, it’s true that there’s more to the emissions picture than what comes out of a vehicle’s tailpipe. Here are some steps that individuals and governments can take to minimize personal vehicle emissions:
Individuals: An electric vehicle only reduces emissions to the extent that it replaces gasoline miles. So choose the most efficient vehicle with the range and capacity you need. Public transportation and small scale personal transportation (bicycles, scooters, and so on) will be considered in a future article.
States: Utility policies that limit charging times reduce the effective range of electric vehicles. Workplace charging facilities increase it.
(In the United States, the Inflation Reduction Act makes significant investments to address these points. I’ll review that legislation in a future article.)
Several years ago, an analysis for the National Renewable Energy Laboratory considered both manufacturing and lifetime emissions for gasoline, hybrid, and battery-electric vehicles. Their assumptions were based on the US expected mileage standards for 2025, which at the time of the report were 40.8 miles per gallon for conventional vehicles, vs. 66.8 miles per gallon for gasoline miles driven by plug-in hybrid vehicles. The original study, completed in 2016, drew a firm line between gasoline and hybrid vehicles. Since then, automakers have embraced hybrid power plants, with many options across their product lines. The current US standard requires a fleet average of about 49 miles per gallon by 2026. Many observers expect further deployment of hybrid engines will be necessary to meet that target.
When examining manufacturing emissions, the NREL study observed that manufacturing of both electric and gasoline vehicles emits carbon. Electric and hybrid vehicles have additional manufacturing emissions due to battery manufacturing and the rare earth elements used in electric motors. In gasoline vehicles, manufacturing emissions are dwarfed by emissions attributable to use of the vehicle. In both cases, emissions due to electricity consumption are a major contributor to overall manufacturing emissions. Actual emissions will depend on the factory’s primary power source, and will be considered in a future article.
To model transportation emissions, NREL considered both electric and non-electric miles, and the effects of low-carbon, medium-carbon, and high-carbon grids. The carbon intensity of the electric grid is defined as pounds of CO2 emitted per kWh. In the US, information about the carbon intensity of regional utilities is collected by the US Energy Information Administration. Here too, recent legislation will have a substantial impact.
Reduce non-electric miles
The number of non-electric miles driven is a major contributor to overall emissions. For example, if the owner believes that the range of their battery electric vehicle is inadequate, they might prefer a gasoline vehicle for long trips. NREL’s analysis assumed, based on Department of Energy data, that gasoline-only vehicles are less efficient than gasoline-powered miles driven by a hybrid vehicle. For that reason, as the number of non-electric miles increases, hybrids have lower total emissions than battery electric vehicles. As hybrids become more popular, households considering a secondary non-electric vehicle will be more likely to choose them. A larger share of non-electric vehicle miles will be attributable to hybrids, reducing the climate impact of those miles.
Besides the composition of the grid itself, two significant policies affect the emissions of electric vehicles.
The first is time-limited charging. Some utilities limit vehicle charging to “off-peak” hours, when electrical demand is otherwise low. Unfortunately, the “base load” plants that supply most off-hours demand tend to be more carbon-intensive — coal plants are not easily dispatchable, while of course solar electricity is not available at night.
Second, an electric vehicle only reduces emissions when it is actually driven. Time-restricted charging effectively limits the range of electric vehicles: if you can only charge the car at night, you can only use one “tankful” of electricity per day.
The flip side of time-limited charging is workplace charging. If time-limited charging reduces the effective range of electric vehicles, workplace charging increases it. Some workplaces, moreover, have installed solar panels in their parking areas, effectively subsidizing low-carbon electricity for their employees.
For individuals, then, the choice between hybrid and electric vehicles depends on local conditions. How clean is the electricity from the grid? How well does a specific vehicle’s effective range — as modified by the availability of charging infrastructure — match the owner’s needs? In many cases, a hybrid may turn out to be the low-carbon choice.
Relative to gasoline vehicles, though, there is no such ambiguity. Even with a high-carbon grid, EV emissions are about 1/3 of a conventional vehicle’s.
Clean the grid
The limitations of electric vehicles also point to opportunities for intelligent policy choices to shape individual and corporate decisions. The first and most important of these is to reduce the emissions associated with the electric grid. The difference between the low-carbon and high-carbon examples in this study is between 27% and 30%, depending on the specific charging scenario. Reducing grid emissions is a force multiplier — it reduces the emissions of every vehicle and every manufacturing plant connected to it.
The second goal of public policy should be to reduce the number of non-electric miles by expanding the effective range of electric vehicles. Potential interventions include encouraging workplace charging facilities, discouraging time-limited charging, and expanding the charging network.
In the United States, utility regulation is primarily a state prerogative. States have the power to encourage renewable generation and discourage time-based charging. The federal government, meanwhile, can facilitate interstate transmission lines and encourage vehicle charging as part of the federal highway system.
Debates about electric vehicles are often phrased as black and white, good vs. bad choices. It’s definitely true that using an electric vehicle for a given trip is unambiguously good. The ultimate goal, though, is to reduce gasoline-powered miles. A hybrid that eliminates range anxiety may do that more effectively than an electric vehicle that sits in the garage.
