Energy developers and industry observers say last week's state decision authorizing a massive power line in San Diego County will boost California's quest to slash planet-warming carbon emissions by shifting power generation from fossil fuels to green sources.

But opponents of the planned $1.9 billion Sunrise Powerlink and future electrical transmission projects say the long-awaited decision will do exactly the opposite.

"I think it's a big step backward," said Bill Powers, an air quality engineer in San Diego who has been one of Sunrise's most outspoken opponents since San Diego Gas & Electric Co. proposed the project three years ago.

"This decision is really an attempt to appease all the inside players," Powers said in a telephone interview Friday. "It's an attempt to try to mold the whole renewable-energy question into the utilities' traditional way of making money."

In a decision with huge implications for California's future, the California Public Utilities Commission voted 4-1 Thursday to greenlight a 500-kilovolt power line along a 123-mile path between El Centro and San Diego.

The route roughly follows Interstate 8 and ends just east of Scripps Ranch.

In authorizing a southern route, commissioners rejected the company's favored route through Anza-Borrego Desert State Park and the North County backcountry.

California, thanks to its campaign to combat climate change, is in a rush to build a new generation of power plants that tap the clean, renewable energy of the sun, wind and underground geysers, and rely less on finite, carbon-spewing coal and natural gas.

In the nation's toughest plan for curbing carbon emissions, announced earlier this month, the state told utilities that they will have to get one-third of their electricity from green sources by 2020.

The two futures

However, entrepreneurs and environmentalists have two very different visions for where the emerging green rush should take California.

Entrepreneurs and electric utilities say the best way to shift away from fossil fuels is to build numerous plants that capture the energy of the brilliant sun in Southern California's deserts and the strong wind in the region's mountain passes.

Studies have shown there are huge amounts of energy available for the taking in those areas.

The environmentalists' vision, on the other hand, is closer to home.

They dream of a future in which the power to cool and light houses comes from solar panels on the rooftops of those homes, and on the roofs of discount retail stores nearby.

Sunrise Powerlink's approval is seen as a victory for the former vision, as electricity from distant power plants can reach California's growing cities only via wires.

"There's no doubt that more transmission lines will be needed in California and throughout the West if we're serious about meeting our ambitious renewable energy and greenhouse gas-reduction goals," said Frank Wolak, a Stanford University professor who studies the economics of utility markets.

Wolak provided expert testimony to Congress during the 2000-01 California energy crisis.

Environmentalists counter that there is more than enough sunshine to keep the lights on.

And if the green rush went in the direction of rooftop solar, they say, there would be no need for visually offensive power lines or potentially environmentally destructive power plants in the desert.

Wires aside, environmentalists worry about the large amounts of water that will be needed to supply solar steam generators and the vast tracts of desert land that may be disturbed during plant construction.

For example, Sunrise Powerlink would serve what is being billed as the world's largest solar plant in the desert west of El Centro.

That 900-megawatt Stirling Energy Systems project would be powered by tens of thousands of mirrored dishes spread over an area half the size of Encinitas.

"It's not a green process," said Sheila Bowers, a Santa Monica lawyer and activist who has been monitoring Sunrise. "It's just so much greener to put solar panels on roofs."

Bowers, who has been fighting a power line that would run to the desert from Los Angeles, said Sunrise also will move California toward a future where consumers continue to be tethered to giant utilities instead of producing their own power on their roofs.

The precedent

Bowers said she considers the commission approval a disturbing precedent, given the army of environmentalists, community activists, attorneys and consumer advocates that fought the line.

"If you guys can't stop it, it is very worrisome for the rest of our state and the rest of our nation in terms of how this (green rush) is going to go," she said.

On the opposite side of the future vision, Steve Cowman, chief executive officer of Phoenix-based Stirling Energy Systems, said last week's decision will pave the way for his company's project to be built, with the assurance that there will be an electrical highway to deliver its power.

The high-voltage wires will be strung from 150-foot-tall, Erector Set-like towers. Ten miles of the line will be underground in Alpine.

SDG&E officials say the project will deliver up to 1,000 megawatts of power to the region at any given moment -- one-fifth of the amount its customers in San Diego County and southern Orange County use on hot summer afternoons.

SDG&E said it needs the extra power. But the project's main selling point has been its ability to plug the region's homes, stores and factories into developing green power in Imperial Valley.

Selling points aside, the bitter three-year battle over Sunrise may not be over.

Michael Shames, executive director of the San Diego advocacy group Utility Consumers' Action Network, said Friday that he intends to petition the state agency for a rehearing by Jan. 18, the deadline for such requests.

His group contends that the commission's decision ignores evidence that the power line is costly and not needed to keep the lights on in San Diego County until at least 2014, and will cause much harm to the environment even though it will avoid the state park.

SDG&E still maintains the line is needed earlier, despite the slow economy and numerous foreclosed homes sitting empty.

"We have not seen any significant decline in electric demand in recent months," SDG&E spokeswoman Jennifer Briscoe said Thursday.

Fully expecting the commission to refuse to hear the case again, Shames said he plans to challenge the state decision in the California Court of Appeal.

SDG&E officials say they are prepared to defend against any such challenge.

The least-cost future

Powers, the San Diego activist, said he welcomes a challenge.

Powers helped steer some of the Sunrise debate in October 2007, when he released the 158-page report "San Diego Smart Energy 2020: The 21st Century Alternative."

In it, he maintained that SDG&E could generate as much energy as Sunrise, at half the cost, by offering incentives to owners of warehouses, parking lots, retail stores and government offices to line roofs with solar panels.

SDG&E officials dismissed the idea as impractical and highly unlikely to succeed.

But the idea gathered steam among opponents in April when Southern California Edison, the huge utility that serves Riverside and several other counties to the north, proposed a rooftop project to generate 500 megawatts, or half the power of Sunrise.

Then last month, Los Angeles Mayor Antonio Villaraigosa announced plans for rooftop solar projects that could combine to generate 780 megawatts in the nation's second largest city.

"I think that's the future," Powers said.

But despite the growing promise of rooftop solar, Wolak, the Stanford professor, said at this point, it is more expensive than the large solar plants being proposed for Imperial Valley and other desert regions.

"It's not the least-cost way to address our greenhouse gas issues," Wolak said.

Contact staff writer Dave Downey at (760) 745-6611, ext. 2623, or ddowney@nctimes.com.