No matter how glorious a spectacle, each day's rising sun is also Maureen Mulligan's reminder of failure.

For the last two years, she has worked the dimly lit corridors of the Capitol, trying to persuade Pennsylvania lawmakers to embrace the sun.

That is, embrace it as an energy alternative utilities must tap in greater amounts than currently required.

Yet as sunset nears on another legislative year in Harrisburg, Mulligan, a lobbyist for the state's two largest solar-trade associations, is still without success.

Pennsylvania's requirement for solar-energy use remains where it was when first set by the legislature in 2004 - 0.5 percent of power provided by utilities must come from the sun by 2021. The state has since slipped behind those that have adopted solar requirements closer to 3 percent, including Delaware and New Jersey.

At the behest of the Pennsylvania Solar Energy Industries Association and the

Solar Alliance - and charged up by her own green convictions - Mulligan has led an unrelenting push to return the state to a leadership position on solar-power commitment.

But her efforts have been no match for the apparent appeal of the status quo.

The opposition has been formidable, led by the Pennsylvania Chamber of Business and Industry, utilities, and the coal lobby.

Mulligan's ammunition isn't as mighty. As one of her admirers, John Hanger, Pennsylvania's secretary of environmental protection, put it: "She doesn't represent a large industry that makes substantial political contributions to candidates and legislators."

But the 58-year-old Carbondale native is from hardy stock, the granddaughter and great-granddaughter of coal miners. As legislators soak up rays on summer vacation, she is readying another plan of attack from her home office in Perry County, on a country road named Greening Life Lane.

It was 1979's infamous accident at the Three Mile Island nuclear-generating station that would inspire the former housing specialist with the Chester County Housing Authority to head in a new career direction - one dominated by energy.

As a community organizer for Limerick Ecology Action for 10 years, she helped educate the public on the nuclear power plant whose twin cooling towers are now a familiar part of the landscape in central Montgomery County, and influenced evacuation planning for that region.

In 1988, Mulligan was hired by the Public Utility Commission, where she was a manager in consumer services. She would stay until 2002, when she left "to explore how I could fit into the upcoming renewable-energy future."

"It looked very promising," she said, "and it was where my heart was anyway."

As a self-employed consultant, she took up the solar cause in 2003, when the Rendell administration was pushing for passage of the state's first mandates for renewable-energy use, known as the Alternative Energy Portfolio Standards Act. At the time, wind was getting most of the attention.

Mulligan was hired by what is now known as the Solar Alliance to make its case. With the industry's potential still unproven in Pennsylvania, her demands were modest, resulting in the 0.5 percent use requirement now considered inadequate in a state with more than 7 megawatts of solar in operation and close to 60 megawatts projected by 2013.

In the trenches with Mulligan was Ron Celentano, a solar consultant and president of the Pennsylvania Solar Energy Industries Association. He was the technical yin to her consensus-building yang.

"She has a very good understanding of how you get your successes, and that's to find common ground," Celentano said.

In the solar field, that is not easy.

Mulligan is doing the bidding of an industry that is "comprised of many different solar companies, each [with] some different . . . business interests," said Chris O'Brien, formerly a leader with the Solar Alliance and now head of market development for Oerlikon Solar in Washington. "Getting that herd of cats together to agree on what Maureen's message was going to be in Harrisburg was a challenge in and of itself."

In conference calls and closed-door meetings, Mulligan said she preached to her constituents: "If solar was going to grow, there had to be room for compromise."

Ultimately, the alternative-energy standards act would pass with bipartisan support and minimal opposition, in large part because its requirements were relatively minimal.

Subsidy programs that followed - such as the Pennsylvania Sunshine grant program overseen by Mulligan's husband, Dan Griffiths, until his retirement from the Department of Environmental Protection earlier this month - would trigger a proliferation of solar projects.

Mulligan read that as a call to action to get Pennsylvania's solar-use requirements boosted to at least 3 percent and the value of its solar renewable-energy credits more predictable, to help build confidence in the industry among private lenders. House Bill 80 in 2009 and this year's successor, House Bill 2405, proposed to do that, but got nowhere despite her never-let-up campaigning.

"I would go into an office and feel pretty good about the dialogue, only to see a half-dozen or more lobbyists against what we were trying to do going in and out of the same doors," she said.

Among them were state chamber representatives contending that the full effect of the 2004 alternative-energy standards were not yet known, making it premature to increase them. The coal industry's worries were over loss of market share and jobs.

Mulligan has fears, too: that the state's gains in solar jobs and converts to that power will be wiped out unless use mandates are enhanced. And so, she prepares another offensive - solar-only legislation she intends to push when the House and Senate return to work next month, assuming she finds a sponsor for it.

Without the multitude of nonsolar issues contained in House Bills 80 and 2405 (carbon sequestration, nuclear-power plant upgrades), Mulligan is hoping a solar-only bill will pass in the less than three weeks of work the legislature has left this year.

She is willing to reduce the proposed solar share from 3 percent to 1.5 percent, "hoping that a lot of our opposition goes away."

That's not likely, considering that solar remains more expensive than most forms of energy, said Terry Fitzpatrick, president of the Energy Association of Pennsylvania, to which most of the state's electric and gas utilities belong.

Though "I like and respect Maureen Mulligan," Fitzpatrick said, "we have a disagreement on this issue."

Contact staff writer Diane Mastrull at 215-854-2466 or dmastrull@phillynews.com.