EAST PROVIDENCE, R.I. -- The solar panels, some 6,400 in row after row, gleam under the September sun, a sea of blue that stretches into the distance.

They are just half of the 12,848 panels that will sit atop the Forbes Street landfill as part of a $9-million project to transform the one-time trash dump for the City of East Providence into a 3.7-megawatt solar field.

When it’s completed in mid-November, it will be the largest solar farm in Rhode Island. It also will be the first one built on a landfill in the state. Twenty-two acres of tainted land with no other use will be repurposed to generate clean electricity, enough to supply about 500 typical Rhode Island homes.

 “You can’t use this land for industry or farming,” William Martin, the Boston-based developer of the project, says as he looks over the field. “This is a beautiful use of space.”

This project is the most obvious sign that Rhode Island’s once-sleepy solar industry has woken up.

The Northeast can’t compete with the sunny Southwest when it comes to solar power. But New Jersey, Massachusetts and other states have proved that, with enough regulatory support and some creative thinking, the region’s solar industry can thrive. Now, Rhode Island is trying to follow.

Crews hired by Martin’s company, CME Energy, and his partner, Hecate Energy, based in Nashville, Tenn., have been at work here since July. They capped the landfill with clean soil, leveled it and then started mounting the Chinese-made solar panels.

On this morning, 35 workers — locals hired and trained by contractor SolBright Renewable Energy — secure aluminum trays to the ground using footlong spikes and weigh them down with 35-pound concrete blocks. Racks, also made of aluminum, are attached to the trays.

Photovoltaic panels, measuring 76 inches by 39 inches, are then bolted to the top and tilted to 30 degrees, the ideal angle at this latitude to catch the sun’s rays.

It’s a relatively simple process. The two crews average about 500 panels a day.

“It’s like Legos,” says Hecate supervisor Mo Younis.

If only building an entire solar industry were that easy. In Rhode Island, developing solar power has been painstakingly slow.

In 2009, when United Natural Foods moved its headquarters from Connecticut to the former American Locomotive complex in Providence, it installed what was then the largest photovoltaic array in Rhode Island, a 167-kilowatt rooftop system.

Two years later, Toray Plastics (America) eclipsed that system with a 445-kilowatt solar field next to its factory in the Quonset Business Park in North Kingstown.

But even that project was small compared with arrays in neighboring states that were up to 10 times larger.

Cumulatively, by the end of 2011, Rhode Island had 1.2 megawatts of installed solar capacity, according to the Interstate Renewable Energy Council. In comparison, Massachusetts had 74.6 megawatts; Delaware had 26.5 megawatts,

Rhode Island couldn’t compete with other states because it lacked regulations to support solar power. A breakthrough occurred in 2011 with the passage of legislation setting up a far-reaching distribution generation program in the state.

It was created as part of the long-term contracting law for renewable energy that governs power purchase agreements for utility-scale projects, such as the offshore wind farm off Block Island proposed by Providence-based Deepwater Wind.

Under the program, a state board sets ceiling prices that developers can charge for renewable energy. The prices vary based on the type of system and its size by taking into consideration the costs of individual technologies, returns on investment and economies of scale. Projects bid within their classes with prices that do not exceed the ceiling. The winning bids are rewarded with 15-year contracts with National Grid.

The law set annual targets for renewable energy, starting at 5 megawatts in 2011 and ending at a cumulative 40 megawatts in 2014, when the program is set to expire.

Rhode Island still lags its neighbors — Massachusetts doubled its solar capacity last year — but now there is hope. In November 2012, Rhode Island had 2.2 megawatts of solar power, with 251 installations, according to the state Office of Energy Resources. The state has another 21 solar projects totaling 16.8 megawatts under contract through the distributed generation program.

Many are big, including a still-to-be-developed 1.1-megawatt project on a former mill site in North Smithfield and a recently completed 2.3-megawatt installation in the Quonset Business Park in North Kingstown that is tied for the largest rooftop array in New England.

“Many of these projects wouldn’t have happened without the program,” says Rep. Deborah Ruggiero, the Jamestown Democrat who introduced the distributed generation legislation in the House and plans to try to extend it in the next General Assembly session.

That’s true of the Forbes Street landfill project. CME Energy was awarded a contract that will pay 23.9 cents per kilowatt hour from its solar panels, a price that is significantly higher than the price for power generated from fossil fuels but lower than the price Deepwater negotiated for its Block Island wind farm.

Would the solar project have happened without a distributed generation contract?

“No,” Martin says. “There would have been no economic basis for it.”

Because Rhode Island is small and densely populated, one of the biggest challenges for renewable energy developers is finding suitable sites.

Without the open spaces that larger states have, closed landfills can offer a promising option for solar and for making contaminated land productive.

Solar power is also largely free of the controversy that has plagued wind energy, particularly in the heavily populated Northeast. Solar panels are relatively unobtrusive. They can be installed low to the ground and, unlike wind turbines, produce no sound or shadow flicker.

Landfill solar projects have been done in Connecticut, Massachusetts and other states. A 1.4-megawatt installation opened in Dartmouth, Mass., in March.

Rhode Island has more than 100 landfills, all but 2 of which — the Central Landfill in Johnston and a Tiverton facility — are closed, according to the state Department of Environmental Management.

Last year, the state Renewable Energy Siting Partnership assessed 56 landfills totaling 2,788 acres as part of its study of potential new sources of green power in Rhode Island.

The study whittled the list to 37 landfills that could support utility-scale solar arrays, those of one megawatt or more, while others could be suitable for smaller installations.

Solar potential on those sites totals 110 megawatts, enough capacity to power tens of thousands of homes.

Plans are being developed around the state. The City of North Providence has been considering proposals since last year to install solar panels on a 13-acre landfill. The Narragansett Bay Commission was awarded a $25,000 loan from the state Renewable Energy Fund for a feasibility study for a closed landfill at its wastewater treatment facility at Bucklin Point in East Providence.

But developing landfill solar projects can be difficult.

The Washington County Regional Planning Council looked at two closed landfills, one in Charlestown and another in Westerly. The Charlestown dump initially looked promising because it had a wide, south-facing slope, says Jeffrey Broadhead, executive director of the planning council. But the closest suitable connection to the power grid was four miles away. The connection alone would have cost as much as $2 million. The Westerly site looked even better, but an inspection of the clay-and-gravel cap concluded that it wasn’t strong enough to support the weight of thousands of solar panels.

“Every single site has to be looked at individually,” Broadhead says.

The Forbes Street landfill occupies 229 acres in the Riverside section of East Providence, much of it forested wetlands.

The city bought the property in 1965 with plans of developing it as a municipal golf course. Instead, four years later, it became a municipal landfill. For a decade until 1979, about a third of the site was used as a dump for household and commercial waste.

The city closed the landfill in 1980 but it was never properly capped. In the years since, East Providence officials considered plans to use the land for recreational space or housing but they were dropped because of the high cost.

In 2010, the city turned to solar power. It made sense. The landfill is a mile from the Kent Street substation operated by National Grid and electrical lines are nearby on Forbes Street. That fall, a request for proposals was released to interested developers.

Martin’s specialty is project finance. He has developed natural-gas-fired power plants in the Midwest and overseas, including facilities in Tunisia and Colombia. He is working on an 800-megawatt plant in Ohio.

He was introduced to state energy officials here through Kevin Stacom, the former Providence College basketball star and Boston Celtics player who is now a consultant and lobbyist in Rhode Island.

Martin had no experience in solar power so he brought on board Hecate Energy, which was working on large solar projects in New Jersey and Texas.

Their proposal was chosen over six other bidders. It is being backed by D.E. Shaw & Co., the New York investment firm that is also financing Deepwater Wind’s effort to build two wind farms off the Rhode Island coast.

The Rhode Island Economic Development Corporation awarded CME a $200,000 grant from the state Renewable Energy Fund, which is supported by a surcharge on electric ratepayers. A few months later, the EDC gave it another $100,000 in federal stimulus funds.

To cap part of the lanfdill, the state Department of Transportation agreed to bring in free of charge 50,000 square feet of gravel worth about $1 million from the demolition of the old Route 195 overpass in Providence.

Under an agreement with East Providence, CME will pay $40,000 annually to lease the land and another $30,600 in lieu of taxes. It will also pay $20,000 to retain on option on expanding the project. If the solar panels generate more than 95 percent of their potential output, the city would receive $20 per additional megawatt up to $31,000.

City officials are already getting calls from other communities and organizations that are interested in duplicating the project at their own landfills.

“It’s not an uncommon model. We’re just the first in Rhode Island,” says city planning director Jeanne Boyle. “It makes sense and we’ll probably see more of these in the state.”

If the solar field is successful, Martin says he will try to double or even triple the size.

Doing that, however, could be tricky. The distributed generation program is designed to support small- and medium-size renewable energy projects. It was limited to projects no larger than five megawatts when Martin was awarded a contract, but the cap has since been lowered to three megawatts.

The program also doesn’t allow multiple projects using the same technology at one site to discourage developers from trying to get around the size limits.

But without a long-term agreement to sell power from additional solar panels, Martin says he won’t be able to expand. He says he will try to convince the state Office of Energy Resources to amend the program, but that could be a hard sell.

Marion Gold, the state energy commissioner, says Martin’s project is “just what the state wants.” But, she adds, the distributed generation program is aimed at diversifying the state’s sources of energy by supporting many projects, not a handful of bigger ones.

“We’re grappling with these issues right now,” Gold says.

As Martin watches workers assemble and install panels, he outlines his case. The power grid will be supplied with more energy from a clean, renewable source. East Providence will be paid more to lease the land, as much as $250,000 a year, earning as much as $5 million over the next 25 years.

And land that can’t be used for anything else will serve a purpose.

“The acreage is here to do more,” Martin says. “I wouldn’t do it if this were farmland. This is the optimal use.”