Renewable energy is nice in theory. But what about in practice?

That's the uncomfortable question raised by a showdown in California. Utilities that need to install clean energy to meet environmental targets are running into environmental opposition when it comes to actually transmitting the juice to where people live.

The L.A. Times reports that California governor Arnold Schwarzenegger is throwing his support behind a proposed 150-mile transmission line that would partially run through a state park. Gov. Schwarzenegger pressed the case in a December letter to California's public utility commissioner Dian Grueneich, though the decision won't be made until this summer. The "Sunrise Powerlink" would link solar power plants in the Colorado Desert with San Diego-but wold also mean hulking high-transmission towers snaking through a state park enjoyed by a million visitors a year.

It's hardly a local phenomenon. From Texas to Scotland, new clean energy projects that might disrupt wildlife habitats (or vacation views) have become an internecine battleground among green warriors. Fighting climate change by adding renewable energy is good; but upsetting pristine landscapes is unconscionable. From the L.A. Times:

"The idea that we're going to sacrifice critical pieces of our environment to protect other pieces of our environment seems a little ironic," said Elizabeth Goldstein, president of the nonprofit California Parks Foundation. "That's an irony I cannot accept."

Buried in that view is a little irony of it's a own - one the governor can't accept. At a climate conference earlier this month at Yale, he railed against green doubletalk. From the Sacramento Bee:

"[I]t's also Democrats and also environmental activists sometimes that slow things down. ... I don't know whether this is ironic or absurd. But, I mean, if we cannot put solar power plants in the Mojave Desert, I don't know where the hell we can put it."

The bottom line is that all power sources need transmission lines to carry electricity to population centers. Since wind and solar power are often sited in remote locations, like ridgelines or deserts, the need for new transmission lines is even bigger. Texas has become a wind power behemoth in recent years, but is still grappling with the costs and complexity of getting all the wind energy onto the power grid. Even clean-energy veterans like Denmark fret over transmission.

The utility behind the Sunrise Powerlink, San Diego-based Sempra, says that if the state wants to have 20% of its electricity generated by clean energy sources, there's no choice but to build. "The huge issue" with California's renewable portfolio standard is the "need for new transmission lines," Sempra president and chief operating officer Neal Schmale told us.

"We have to balance an array of competing considerations, and then get assaulted by single-issue advocacy groups," he said.