Given the red-team/blue-team dynamic of American politics, it was probably inevitable that discussion of energy policy would degenerate into a debate between drillers and renewers—between those who want more domestic oil exploration to the exclusion of other power sources, and those who want the U.S. to kick its petroleum habit entirely. Both sides are being unrealistic.

Even with painful conservation measures and a crash program to develop alternative energy supplies, the United States will be relying on fossil fuels for many years to come. That's not oil-company propaganda. It's the conclusion of the National Academy of Sciences, which says even hundreds of billions of dollars devoted to plug-in electric cars would not change American gasoline consumption for at least a couple of decades.

But suppose the U.S. could switch to an all-electric fleet overnight. Assuming the entire grid did not melt from the demand spike, where would the electricity come from? Primarily from coal-burning and nuclear power plants. Alternative energy sources such as wind and biomass are utterly incapable of generating the juice necessary to meet current demand, let alone the energy needed to power millions of cars and trucks.

Consider: The U.S. uses nearly 4 terawatts of energy per year (a terawatt is 1 trillion watts). According to Reason magazine's science editor, Ronald Bailey, relying on the work of MIT's Daniel Nocera, putting a windmill on every available spot on the globe that has class 3 winds or higher—i.e., winds in excess of 11.5 mph—would produce 2.1 terawatts at best. And we're not going to be piping in wind energy from the Mongolian steppes. Biomass could produce 10 terawatts—if every person on the planet stopped eating, and we converted all of the world's crops into fuel for machines instead of people.

Even if the current grid did supply enough electricity to power our transportation needs, the U.S. still would have to rely on gasoline for a great deal of its movement. Take the Chevy Volt, America's best-selling electric vehicle. It averages a mere 30-40 miles on battery power alone. Then it needs to recharge for 10 hours. The Volt is a four-door compact. Imagine how long it would take to recharge a school bus. And if you leave the Volt unplugged in cold weather, then the engine must burn gasoline until the battery warms up to its minimum functioning temperature—somewhere between 32 and 50 degrees Fahrenheit.

Foes of measures to expand drilling—such as the bill passed by the House last week that would open up Virginia's shores for exploration—point out that America consumes 22 percent of the world's energy but contains only 1.5 percent of proven petroleum reserves. Note the word "proven": It refers to the amount of commercially recoverable petroleum available under current government regulations.

In other words, no matter how much petroleum someplace such as the Arctic National Wildlife Refuge contains, if drilling is forbidden there by federal policy then it doesn't count as part of the U.S. reserve. Critics who say we shouldn't permit drilling off Virginia's coast because the U.S. has only a small share of the world's proven reserves are making a circular argument. If drilling were permitted, then we would have much bigger reserves.

All of the above constitute arguments for continued exploration and drilling. What they don't constitute are arguments against developing alternative energy sources. Yet many red-team cheerleaders for oil and gas insist that pursuing alternative energy sources is a fool's errand. It isn't. Just because they cannot meet our needs today does not mean they never will, and insisting otherwise is akin to astronomer F.R. Moulton's 1932 prediction that "there is no hope for the fanciful idea of reaching the moon, because of insurmountable barriers to escaping the Earth's gravity." Human ingenuity knows few limits.

While wind likely will remain of limited benefit, solar energy holds great potential. As Reason's Bailey notes, more energy from the sun strikes the planet in one hour than humanity uses in the course of an entire year. The trick is figuring out how to harness it in economically feasible ways. Unlike nuclear power, solar energy doesn't leave behind deadly toxic waste. Unlike petroleum, solar power is not—at least for human purposes—finite. And unlike coal, oil and gas, it does not contribute to global warming. (Conservatives, who like to think of themselves as hard-nosed realists, are going to have to stop denying the realities of climate change. True, not everything is known. But not everything is known about gravity, either, and it's still not safe to jump off a bridge.)

Of course, solar power presents challenges of its own—e.g., nightfall. And there are environmental objections, too. When several companies proposed building solar arrays in the Mojave Desert last year, Wildlands Conservancy's executive director said it "would destroy the entire . . . ecosystem," and Calif. Sen. Dianne Feinstein introduced legislation to stop them.

That might be the biggest obstacle to our energy solutions of all: No matter which way the country turns, someone is standing in the way yelling, "Stop!" But given realistic projections of supply and demand, we shouldn't be arguing whether to develop this energy source or that one; we should be developing them all.

A. Barton Hinkle is a columnist at the Richmond Times-Dispatch. This column originally appeared at the Richmond Times-Dispatch.