Behind their shared pride in the Golden State’s green incentives, two types of renewable energy proponents are fueling a debate over the direction California’s solar movement—and perhaps that of the nation—should take. Most of the high-profile solar development projects in California and elsewhere across the country are large-scale power plants, which sell electricity to utilities companies, which in turn funnel them into nearby homes. It’s the traditional model, but it’s not going uncontested. There are some solar power supporters, like engineer and energy consultant Bill Powers, who don’t think bigger is better.

“The solar plants in the desert are albatrosses,” Powers said. “We’ve come to a point where (photovoltaic solar) is either going to be in the remote installations or it’s going to be in the urban core. It’ll be much more beneficial for those solar panels to be sitting in the urban core where they’re going to be used.”

Powers argues that California should cover every rooftop—commercial buildings in particular—with photovoltaic solar panels, which don’t need to clear as much bureaucratic red tape as utility-scale plants do and whose prices have dropped roughly 40 percent over the past year alone. No more waiting on a government land permit for years, or building lengthy new power lines across the desert. (Not to mention stand-offs with wildlife protectionists where endangered species are involved.) Furthermore, small-scale solar wrests power away from the utilities and places it back in the hands of the home or business owner.

Yet distributed generation is not without its flaws. For one, it’s expensive—more expensive (17 percent more, according to the California Energy Commission via the San Francisco Chronicle) than a utility-size solar thermal project, whose price is governed not only by economies of scale, but also by an entirely different (and cheaper) technology ill-fitted for private rooftop use.

“Because of the economic and operational issues, I think we’re going to see large-scale, grid-connected power for a long, long time,” said Jonathan Marshall, a spokesman for Pacific Gas and Electric Co.

Granted, Marshall is speaking on behalf of a player positioned to benefit from the dominance of large-scale solar, so it’s safe to assume he’s speaking with a bias. But even some advocates for small-scale energy production, such as Carl Zichelle, regional director for the Sierra Club in California, admit that the days of the traditional model are still far from over.

“We need to do it all,” Zichella said. “It’s quite possible we can get more distributed generation than we thought, and if we get enough, we can build fewer big plants. But I haven’t seen any studies I think are credible that say we won’t need any.”

With utilities still required to achieve a 20 percent renewable energy target by the end of 2010—a target they are expected to miss—it’s unlikely that large-scale projects will disappear anytime soon. But with the right incentives, technologies and momentum, perhaps a push for a new solar model is on the horizon for 2010.