Several trash haulers are dwarfed by the trash mound at the state’s Central Landfill. The trash can supply enough methane gas to provide electricity to more than 38,000 homes, according to the New Jersey energy company that plans to build a power plant.

The Providence Journal / Kathy Borchers

JOHNSTON — An $80-million project to generate electricity from the methane gases that are given off by Rhode Island’s trash drew support from local and state officials yesterday morning.

Executives from a New Jersey company, Ridgewood Renewable Power, unveiled detailed plans and announced that their project, to start this spring, will more than double the output of gas-fueled electricity generation at the state’s Central Landfill, creating the second-largest such facility in the United States.

The proposed plant would churn out 41 megawatts of electricity — enough to supply more than 38,000 homes, according to the company, which aims to bring the new plant online late in 2010.

Over three decades, the facility’s projected energy output would be on par with what a coal-burning facility would produce with about 2.9 million tons of coal — enough to fill a freight train 275 miles long, the company said.

“I think this is one of those projects that’s a win-win,” Governor Carcieri said, at a news conference. “It’s a great effort. The fact is, we need this as a critical part of our state.”

The project, like a proposal for an offshore wind farm, will help expand the state’s renewable energy infrastructure, Carcieri said, noting that energy-producing states have the healthiest finances.

“From my perspective, we’re looking for a lot of good news anywhere we can find it,” he said, “but this is real good news.”

Ridgewood first set up shop at the landfill in 1996 and the company operates a collection of methane-fired generation facilities.

A network of pipes runs through the piles of landfill debris and captures the gases produced by the natural decomposition. The pipes feed three power plants.

Two of those facilities are in an area where the landfill’s steward, the Rhode Island Resource Recovery Corporation, will need to dump trash in the future. Under the terms of a new contract with Resource Recovery, these two plants would be removed.

A third plant, which provides about 6 megawatts of electrical output, would remain at the landfill site and supplement the new 41-megawatt facility.

The project will unfold in three phases, encompassing upgrades to the existing collection system, as well as the construction of both the power plant and a $10-million treatment facility to cleanse and purify the gases.

The existing system, a single-cycle approach, lacks the necessary capacity to harness all of the gases released by the state’s trash, so excess gases are burned off.

The new two-cycle system would use almost all of the gas and produce energy at a much higher rate, according to Stephen Galowitz, Ridgewood’s managing director.

In the first cycle, landfill gases would power five large turbines that were likened yesterday to jet engines. In the second cycle, the byproduct of the turbine process — a tremendous amount of heat — would feed steam-driven electricity generators.

“It’s a fascinating process and we’re very proud of it,” said Ridgewood’s president, Randall Holmes.

Meanwhile, the new arrangement would allow Ridgewood to process more gas and also would help clear the way for landfilling operations in the years ahead, according to Resource Recovery’s executive director, Michael O’Connell.

The contract includes rental provisions for Ridgewood’s new site across the street from the landfill and it allows Resource Recovery to sidestep about $5 million in costs associated with caring for the gas-collection system, O’Connell said. Those duties would be handled by Ridgewood.

“This is when capitalism and the environment come together and that’s really the perfect storm,” O’Connell said.

“It’s going to be good for the taxpayers of Rhode Island,” he said.

Carcieri lauded O’Connell’s work on the deal but quibbled with his language.

“I think a perfect storm is negative,” he said.

“I think of this as a virtuous circle,” he added, referring to “the beauty” of generating energy from waste.

mreynold@projo.com