A bunch of Midwestern governors, fretting about global warming, made some silly promises to each other about energy this month. But on the upside, they seem ready to give a dam.

The 11 governors signed what they term a “platform,” pledging to make people be more efficient, to subsidize ethanol, and to use less power — an improbable thing. A big part is a pledge to use more “renewable” electricity. The booklet heralding this has lots of pictures of windmills.

And some pictures of dams, which is big news. Hydroelectricity doesn’t get much respect. It accounts for about 6.6% of the nation’s power, compared to 0.4% from wind, but environmentalists usually exclude it when talking about “renewable” energy. Illinois, Minnesota, and Wisconsin have all ordered utilities to get certain portions of their power from renewable sources; all three won’t count power from big dams.

That may change. There at the Midwestern Governors Association was Premier Gary Doer of Manitoba, whose province generates huge quantities of utterly carbon-free power from dams and sells a lot of it to Midwestern Americans. It has roughly again as much potential power flowing unfettered into Hudson Bay.

Mr. Doer’s presence wasn’t coincidence. “I consider hydro renewable,” said the meeting’s host, the governor of Wisconsin, Jim Doyle, to reporters and editors as Mr. Doer sat by his side. “We have to make a little change in our law to assist that.”

In Wisconsin, the Legislature tried changing that law last spring so utilities could get credit for buying Manitoba juice. The tree-huggers flipped. “This takes a giant step backwards,” a Sierra Club official said. “This completely undercuts the idea of utilizing Wisconsin resources,” an environmental lobbyist said.

I thought the idea was to swap out coal-chugging power plants for something cleaner and to favor energy that will last as long as the sun shines and the rains fall. Which pretty much describes hydroelectric plants. Wisconsin’s got some, though they’re small and another set of activists is trying to get dams ripped out. In Manitoba, most of the big plants are way up north where there aren’t many people to be bothered, and they typically haven’t involved flooding great swaths of land. The operator, Manitoba Hydro, has already cut back on some projects’ power capacity to avoid flooding, doing so after consulting with Indian tribes. In short, it’s benign power.

So now at least one governor — Mr. Doyle, a Democrat who customarily includes greens in his base — is saying he wants to toss aside his state’s legal allergy to Canadian dams. Another agreement by the governors makes it easier to build long-distance power lines. Such lines could serve ten thousand windmills and a bunch of power plants that burn cow patties, certainly. But they’ll bring in Canadian power, too, when push comes to shove. Which it will. Windmills are nice, but they’re costly on a per-kilowatt basis. Dams are expensive, too, but as one Manitoba Hydro guy pointed out, “they’re good for a hundred years, you know.” So power from them ends up being cheap. And cheap power is one of the first things any region boasts of when trying to draw new industry. The windmill-and-cow-dung crowd says their schemes will create new jobs, but they’d be vastly outnumbered by the kind of growth the Midwest would get by buying renewable power cheap instead of dear.

The governors didn’t admit to wanting cheap power. They pledged to cut the region’s electricity use 2% by 2015 and to cut it 2% a year thereafter. This would be unprecedented: The nation’s electricity consumption fell from one year to the next only four times since 1949, all associated with economic dips. Power consumption moves in virtual lockstep with economic growth. Energy efficiency has doubled since 1970, but that’s just meant we can afford to buy more — 41% more by 2030, predict the feds.

This isn’t bad. Unless we seek stagnation, simple population growth means we’ll need more power. It’s better for the air if all those new people fuel their cars not with ethanol but by plugging them in overnight. Engineers keep making electricity more useful. It’s hard to see where actually using less of it would signal progress.

Unless your view of progress is less: less traveling around, even by electric car. Less air-conditioning, more sweat. Less refrigeration. Less light. More composting toilets to supply the stove with methane. Read enough essays about “relocalizing” power, about changing economic paradigms, and you suspect that for some environmentalists, carbon isn’t so much the motive as a lever.

They don’t like coal-fired power, which is cheap, because of the exhaust. They don’t like nuclear power, which is emissionless and potentially cheap, because of the waste. They don’t like hydropower, which doesn’t put out waste and is cheap, because … um, because it disturbs the moose and isn’t local.

Right. This suggests a profound disinterest in trade-offs, in recognizing that a dam is less polluting than a coal plant. If instead you think the problem is that people use the power, then getting it cheap, even if clean, doesn’t help your cause.

The governors, to their credit, seem to have at least an inkling that natural resources are things you use. Then, if you regard carbon dioxide as the breath of hell coming to bake the planet, an ordinary sense of proportion will tell you that a ready supply of power that doesn’t burn anything and doesn’t cost much is worth pursuing.

Mr. McIlheran is a columnist for the Milwaukee Journal Sentinel.