In an interview with the Business Journal last week, Craver said that even though households that switch to rooftop solar might stop paying the electric utility, they still use the grid and therefore need to pay their fair share to maintain it.

“When an air-conditioning unit is turned on or a pool pump turns on, these appliances use huge amounts of electricity all at once, more than the solar panels can handle,” he said. “Where does that extra power come from? It comes from power supplies elsewhere on the grid. And what about when they have excess power they want to sell? We pay them for the power, but they must still use the grid to transmit the power. And that grid requires more strengthening than ever before.”

Craver said that the maximum $10 monthly fee is modest. He said that about one-third of a typical $100 monthly bill goes toward maintaining the transmission grid, what he referred to as “fixed costs.”

But rooftop solar power installers object because they say residential customers with solar panels already save the utilities money as they cut the amount of power the utilities have to procure.

“Right now, with the shutdown of the San Onofre nuclear plant, there’s all this talk about where we’re going to get the replacement power and how much more that power will cost,” said Button at Verengo. “Well, if enough people switch to rooftop solar, Edison won’t have to get as much power, and that will save all Edison ratepayers money. That’s why I don’t understand why the utilities would back this fee.”

Amid this controversy, Edison took its first step into the rooftop solar business. The company announced last week it was buying Chicago solar rooftop provider SoCore Energy LLC for an undisclosed sum.

But Craver said Edison was not trying to play both sides of the issue. He said all the SoCore rooftop installations would remain outside of California, mostly at retail chains and other large industrial and commercial properties.

“Solar rooftop generation is a good business to be in,” he said, “especially in the commercial and industrial markets where solar power can be used as a hedge against power rate fluctuations.”

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