AUGUSTA –– A bill that would greatly expand solar energy development in Maine was passed Tuesday by a legislative committee, but the party-line vote signaled that it stands little chance of becoming law.

Democrats on the Energy, Utilities and Technology Committee backed the proposed measure, while Republicans voted against it. The vote was 7-5. Two Republican-sponsored amendments failed to win support.

The issue will next be taken up by the House. But the measure is opposed by both Republican leadership and Gov. Paul LePage, so unless Democrats can muster a two-thirds vote to override an expected veto, the bill will fail.

If the Legislature doesn’t act on solar energy, the issue will next wind up at the Public Utilities Commission, which by law is set to examine net metering, a key financial incentive that helps lower the cost of solar-electric panels by paying the owners of solar panels for excess power they produce.

Democrats wanted to avoid this outcome, because they fear that the PUC, which has three commissioners appointed by LePage, will gut the net-metering subsidy.

That prospect, which had been anticipated for months, led clean-energy advocates on Tuesday to predict dire consequences for the state’s fledgling solar industry.

“It’s going to kill solar,” said Assistant House Majority Leader Sara Gideon, D-Freeport, who championed the bill. “Solar’s going to come to a standstill.”

But House Minority Leader Ken Fredette, R-Newport, said after the vote that Republicans were opposed because they don’t think the industry needs subsidies at this point to grow. He said it’s still possible his members can support an amendment that would have provided a more-limited support for solar development. He said Republicans would decide in the days ahead whether to press for that amendment, or send the issue to the PUC for its review.

The bill supported by Democrats aims to grow solar capacity in Maine from about 18 megawatts today to 250 megawatts in five years, enough to power 40,000 homes, and about 2 percent of the state’s power needs. But LePage has long expressed the view that net metering is a burden to other ratepayers.

In the committee, much of the discussion centered on whether the proposal would be a benefit or burden to ratepayers. Lawmakers had to sort through complex details of vastly conflicting estimates from the PUC, which predicted customers would pay $22 million more on their electric bills in the fifth year of the new law, and from the Office of Public Advocate, which saw ratepayer benefits of more than $122 million over a 20-year period.

Depending on which estimate is taken, the cost to ratepayers in the most expensive year would either be an extra 80 cents a month or an extra 40 cents a month on the average home bill, according to Public Advocate Tim Schneider.

Beyond rates, there is another consideration: economic development. Advocates say the proposal could create 800 or so new jobs in the solar installation field over five years.

Fortunat Mueller, managing partner and co-founder of ReVision Energy, the largest solar company in the state, said other New England states are outpacing Maine in developing solar energy. “Solar jobs are being created by the thousands in the states to our south,” he said, “and it’s long overdue that Maine get into the game.”

The jobs issue could have greater currency in a legislative debate, at a time when paper mills are being shuttered and skilled workers are being laid off, especially in rural Maine. Solar advocates make a case that some former paper workers could find new careers in the clean-energy economy. It remains to be seen if enough Republican lawmakers are swayed by this argument, and are willing and able to break ranks with LePage and party leadership.

Dylan Voorhees, the clean-energy director at the Natural Resources Council of Maine, said he was disappointed by the committee vote, but held out hope that lawmakers would evaluate solar on their own and be open to another possible amendment.

“It’s disappointing that politics trumped the best interests of Maine people,” he said.

If the Legislature fails to act, Maine has a law saying that the PUC will review net metering rules when solar generation hits 1 percent of a utility’s load. That threshold was crossed last year in Central Maine Power’s service area, on one hot day in August.