One of the most popular strategies for reducing dependence on fossil fuels is to “electrify everything.” That’s because even with today’s energy mix in the United States—according to the Energy Information Administration, 61% of electricity generation was from fossil fuels—electric cars and light trucks still have far lower emissions than their gasoline-powered equivalents.

But they still do have emissions, from both the generation of the electricity that powers them and the upfront carbon emissions released during the manufacture of the vehicle.

This is why we have often written that three things are needed for the electric revolution: reduce demand. clean up electricity, and electrify everything. In houses or cars, size and efficiency still matter because there are only so many clean kilowatts out there and they are unevenly distributed.

Writing for the American Council for an Energy-Efficient Economy (ACEEE), transportation analyst Peter Huether looked at the question of efficiency in an article titled “9,000-Pound Electric Hummer Shows We Can’t Ignore Efficiency of EVs” He compared a small electric car to the Hummer:

And this is without even considering the upfront or embodied carbon emissions from making the vehicles. It’s just straight carbon dioxide (CO2) out of the smokestack instead of the tailpipe. Huether noted these matter too:

Huether called on the Environmental Protection Agency to develop efficiency standards for electric vehicles: “All EVs do not have the same impact on the environment, and our vehicle regulations should reflect that.” The efficiency is a function of weight and aerodynamics, with smaller and lighter vehicles being more efficient.

But even among vehicles of the same weight, there can be significant variations; in the 5,000- to 5,500-pound range of weights, efficiencies range from 25kWh/100 miles to nearly 48 kWh/100 miles, just under half as efficient. The Electric Hummer needs 62 kWh to go 100 miles; that is a lot of juice, enough to run the average American home for two days.

Huether concluded we need regulations and standards, just as there are for gasoline-powered cars, with greater emphasis on efficiency. He wrote, “Greater EV efficiency can reduce emissions from driving and manufacturing the vehicles and increase range and reduce costs.”

Huether is not alone in questioning the need for such big inefficient vehicles. The Drive’s James Gilboy and Peter Holderith make many of the same points about how efficiency matters. “Lower efficiency means charging more often. Charging more often means more energy consumption,” wrote Gilboy and Holderith. “You can see where this is going.”

They also do a great explanation of the importance of embodied carbon, one of the first I have seen applied to cars outside of Treehugger. They noted companies are not revealing the upfront carbon data—only Volvo does with the Polestar. They extrapolated from the Polestar to actually try to estimate the upfront carbon for the Hummer EV, coming up with 50.6 metric tons, which is “more than triple the 15.2 metric tons of CO2 emissions Americans averaged in 2018.” This is another important milestone, where they demonstrated how important embodied carbon is and made it relatable.

They concluded:

In the end, there is no question that every electric vehicle is a dramatic improvement over its gasoline-equivalent. But just as in gasoline-powered vehicles, size, weight, and efficiency matter for both upfront and operating carbon emissions. And that Hummer is a climate-killer—no matter what it runs on.