Tesla CEO Elon Musk

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Tesla CEO Elon Musk believes that electrifying personal transportation will require electricity generating capacity to double.

And while ramping up output might feel daunting for anyone worried about the transition to electric vehicles, investors—and U.S. consumers turning on the lights—shouldn’t worry.

“If we shift all transport to electric than electricity demand approximately doubles…this is going to create a lot of challenges with the grid,” said Musk on Wednesday at CodeCon, a conference held at the Waldorf Astoria in Beverly Hills, Calif.

Now, Musk is no fool: He has built several entities worth tens or even hundreds of billions of dollars. And Tesla (ticker: TSLA) is essentially the first successful American car manufacturing start-up of the past 90 years.

But in order to make the EV revolution a reality, utilities would need to generate a lot more electrons. Cars, after all, would get their power from electric plugs instead of gas pumps.

If electricity demand doubled overnight, the U.S. might experience rolling blackouts—but that dystopian vision is impossible. It will take a generation to make a dent in the personal transportation fleet: Today, there are about 276 million cars, trucks, buses and motorcycles on U.S. roads. About 1% of them are all-electric.

Even if President Biden has his way, and 50% of new car sales in the U.S. are all-electric by 2030, the U.S. vehicle fleet might be just 15% all-electric by the end of the decade. It will take a generation or more to convert all vehicles from gas to electric power. There might be as many as 50 million all-electric vehicles on the roads by 2030, but that shouldn’t be enough to cause a electricity crisis.

Still, that doesn’t mean the U.S. shouldn’t think and prepare.

Consider how many barrels of oil the U.S. consumes each day: roughly 19 million. That’s 7 billion barrels a year. About 40% or 50% of the barrels are used to power cars, according to BP’s annual energy report. (Planes and homes need their fuel, too.) Cars burn about 3 million barrels of oil each year. 

A barrel of oil has about 6 million British thermal units, or BTUs, of energy. That’s translates to about 1,700 kilowatt hours of electricity. This means that American cars use about 5,000 terawatt hours of electricity each year. Total U.S. electricity consumption in 2020 was roughly 4,000 terawatt hours, according to the EIA.

Musk is right: For the U.S. to have only electric vehicles, electricity-generating capacity would have to basically double.

The demand increase is so slow, however, that there is time. If EV penetration of new car sales reaches 90% by 2040, the U.S. vehicle fleet will likely be about two-thirds electric by then. The U.S. economy has years to plan. Still, vehicle electrification will cause issues bigger than just building more power plants. “Even if you increased sustainable generation at the utility level, you’re still going to have a problem at the distribution level,” said Musk.

More power means more power lines, along with more utility substations that require space in cities. Musk says local generation—at the home level—is part of the solution. That’s why Tesla also sells solar roofs and battery backup-power systems to residential customers.

The techno-optimists likely have no doubt believing that business and technology will meet the rising demand for power. There is, after all, profit in meeting demand for anything. And profit is what investors expect their portfolio companies to pursue.

“We need large sustainable power generation developments…paired with battery packs…for continuous power,” added Musk. “A lot of good things are happening in this regard.”

That’s the vision he is building his company around.

Write to Al Root at allen.root@dowjones.com