PHOENIX - A new lawsuit will tests the limits of state utility regulators to restrict the ability of companies to ship power generated here to other states.

Southern California Edison is asking Maricopa County Superior Court Judge John Buttrick to void a ruling by the Arizona Corporation Commission blocking construction of a new power line from the Palo Verde Nuclear Generating Station to California.

Commissioners, in rejecting the application in May, made it clear they were influenced by the fact that California has not built any new power plants in decades. Kris Mayes referred to the proposed line as "a 230-mile extension cord into Arizona.''

But Thomas Campbell, the lead attorney for the California utility, said the commissioners improperly considered factors they are not legally allowed to weigh in refusing to give the go-ahead for the power line. Campbell said that includes the fact that having California customers bidding for power from the nuclear plant would drive up costs for Arizonans.

Specifics of the commissioners' reasons aside, Campbell charges that the decision runs afoul of federal constitutional provisions which limit the ability of states to affect interstate commerce.

That, he said, includes the sale and transmission of power. But Jeff Hatch-Miller, one of the commissioners, said this isn't a simple question of allowing electricity to be transmitted from one place to another. Hatch-Miller said he and his colleagues are required to look at all the impacts of the power line on Arizona.

And he said the evidence shows that making it easier to ship power to California would harm the state. Some of that is technical. "Power is sort of like water,'' he said. "Wherever there is a sucking sound on the line, wherever there is a demand, that's where the electrons will go.''

What that means, he said, is if the demand from California overwhelms the system, the new interconnection could affect the reliability of the power supply in Arizona. "You're talking about a huge impact on the health and safety of the state,'' he said.

And he said the record shows that while Arizona has excess power now, that won't be the case in the future.

The feeling is shared by other regulators. "I don't want Arizona to become an energy farm for California,'' Commissioner Bill Mundell said when the application was denied. "This project, if we approved it, would use our land, our air and our water to provide electricity to California.''

Yet the commission concluded that having the line would make it easier for California utilities to buy power from Palo Verde on the "spot'' market - meaning as needed when available. And that demand would drive up the price for spot energy by 5 percent, energy that ultimately would cost Arizona customers $242 million over the life of the line.

"I'm not against California, I'm not against Californians,'' Hatch-Miller said. He said his concern is the economic impact of the line on Arizonans and assurances that there will be enough power during peak summer months.

Some of the legal fight surrounds other issues considered by the commission in its denial. One of those is about the commission's concerns about environmental impact of the new power lines, particularly through the Kofa National Wildlife Refuge, a habitat for endangered desert bighorn sheep.

Campbell pointed out that the towers will be along the same route as a previously approved power line. He also said there were no objections from the U.S. Bureau of Land Management or the U.S. Fish and Wildlife Service. Campbell said the state commission lacks authority to consider impacts on federal lands.