State regulators forced Georgia Power on Thursday to expand the amount of solar energy it generates, putting the company on the rare losing side of a political battle. But the vote was just a skirmish compared with bigger battles ahead for the powerful utility.

It faces a double-whammy of upcoming votes before the Public Service Commission on approving new costs for its nuclear expansion project and a proposed 6 percent rate hike to fund new equipment. And a legislative fight looms over a proposal to create a new solar monopoly that could challenge Georgia Power's grip on state utilities.

The all-Republican commission’s 3-2 vote was a significant defeat for the Atlanta-based company, which had warned it already generated more than enough energy for its customers. Opponents also said that adding 525 megawatts of solar by 2016 would inevitably drive up rates, although Georgia Power, in a surprising about-face, backed off that argument on Thursday after months of making that case. Instead, its attorney said for the first time that the added solar likely wouldn’t affect power bills.

In the aftermath of Thursday’s vote, the odd coalition of environmentalists, conservatives and solar startups behind the expansion barely paused to savor their win. Some emboldened activists said the victory gave them new hope they could successfully challenge the utility on other contentious issues.

The Georgia Tea Party Patriots, which rallied conservatives behind the solar expansion, vowed to fight Georgia Power over a proposed rate hike set for a vote in December. The increase, designed to pay for new pollution controls on coal-burning power plants, would add about $8 to the typical residential customer’s monthly bill.

Environmentalists said they would step up pressure over the rising costs and scheduling delays for the construction of two new nuclear reactors at Plant Vogtle in Waynesboro. The commission will vote in October whether to approve millions of dollars in overruns, which could eventually be recovered by customers.

And legislative critics saw Thursday's vote as an opening for new incursions against Georgia Power. Some are rallying behind a proposal by state Rep. Rusty Kidd that would authorize a new solar utility to compete against Georgia Power. Kidd, an independent who represents a Middle Georgia district where a coal-powered plant is closing, said Georgia Power is acting more like "another profit-making corporation" than a public utility.

“Even with this abundance of power currently generated, Georgia Power has requested a 6 percent rate increase,” Kidd said. “For what purpose? To make Georgia Power more money?”

Georgia Power may be hedging its bets. Kevin Greene, the utility’s top attorney, declined to say Thursday that a solar expansion would force higher rates — a position the company had previously pitched — and said it would do its “best to implement the decision of the commission.”

An upset Commissioner Stan Wise, the most outspoken opponent of the solar expansion, suggested the utility wasn’t aggressively fighting the move because it was holding its considerable firepower for the fights ahead.

“I’m really disappointed in the company today,” said Wise, who was visibly shaken after the vote. “It’s one thing for the commission to make a bad policy decision, but it’s extraordinary that the company would lay down and take it.”

Officials with Georgia Power did not respond to questions addressing the proposed rate hike, cost overruns or Kidd’s bill.

The utility’s lawyers are working behind the scenes to fine-tune arguments for the two other high-profile votes pending before the commission. And the company has sent the signal it is watching Kidd’s proposal by using its political action committee to dispense more than $22,000 in campaign donations since the legislation was filed in March.

The amount itself doesn’t stand out; the utility has given greater sums in past years. What’s noteworthy is the fact that the funds almost exclusively went to House Republicans who will determine its fate.

The commission’s vote Thursday forced Georgia Power to make a considerable strategy shift. The utility’s 20-year plan had excluded adding any traditional or renewable energy, and Commissioner Lauren “Bubba” McDonald rallied the votes of fellow members Tim Echols and Doug Everett to secure the solar expansion. Wise and Chuck Eaton voted against it.

On the overall plan, the commission voted 4-1, with Eaton joining the majority.

For Georgia’s nascent solar industry, new opportunities await, though it’s unclear whether everyone will see it that way. The newly approved program requires Georgia Power to buy the bulk of the solar power from large solar farms instead of rooftop solar arrays, where the electricity is distributed close to the demand.

Regardless, the amount of solar Georgia Power will add to its electricity mix is enormous compared with the 50 megawatts of solar the commission required in 2011. The 525 megawatts now required is roughly one-fifth of the capacity of the two reactors under construction at Plant Vogtle.

One the biggest winners is the fledgling Georgia Solar Utilities, whose president, Robert Green, was one of the most ardent supporters of the expansion plan. Moments after the vote, he was already looking ahead to the next fight.

“I think it’s certainly going to send the Legislature a message on what the PSC thinks about it,” he said.