PROVIDENCE — Rhode Island has a wood problem. Although the state has no wood-burning power plants, it relies heavily on wood power for electricity, specifically for the renewable energy that flows through local electric sockets. The problem is that wood power is considered harmful to the environment, especially for its high levels of carbon dioxide emissions.

One of the state’s key alternative energy incentive programs, the Renewable Energy Standard (RES), is largely responsible for Rhode Island’s use of wood power. The RES was designed to stimulate renewable-energy construction in Rhode Island and around New England by requiring that a portion of the electricity delivered by utilities originate from sources such as wind and solar. RES rules also allow for hydropower, landfill gas, food digesters and electricity from wood-burning power plants.

At a Feb. 9 Statehouse hearing, the RES was praised by environmental advocates for stimulating the local renewable-energy sector since the program launched in 2007. So far, nearly all of the “green” power has been generated in neighboring states. It wasn’t until 2013 that 18 percent of the RES power originated in Rhode Island, and nearly all of that electricity was from the troubled Broadrock Renewables LLC plant that runs on methane from the Central Landfill in Johnston.

While biogas isn’t the green energy of choice for environmentalists, it’s generally tolerated because it burns a potent greenhouse gas that might otherwise escape directly into the atmosphere.

However, there is a growing belief among researchers that emissions from wood-fueled power plants release more carbon dioxide than fossil fuels. Wood power, also called woody biomass, is often classified as carbon neutral because of the perception that carbon emissions are recaptured from planting new trees.

But there is increasing evidence that the carbon dioxide takes decades to offset even if the wood is harvested from the most sustainably managed forests. A 2014 report concluded that woody biomass emits 50 percent more carbon dioxide per megawatt generated than coal and 800 percent more CO2 than a natural gas power plant.

More than 50 percent of the renewable power used in Rhode Island’s RES comes from woody biomass, according to the latest annual review of the program for 2013. All told, wood accounted for about 4 percent of Rhode Island’s overall electricity supply that year. While not a huge portion, it still vastly exceeds the electricity generated from wind and solar. Preliminary numbers for 2014 reveal that wood power accounted for 30 percent of the RES; landfill gas delivered 44 percent and wind accounted for 8 percent. The official numbers are expected soon from the Public Utilities Commission.

Massachusetts has confronted the problem by severely restricting the use of woody biomass in its RES program. In 2012, the Bay State also enacted new regulations that classify biomass power plants as renewable only if they follow strict standards, such as sourcing wood from byproducts from lumber mills and forestry residue. Displacing virgin forest is prohibited.

In 2013, the most recent year reported, Massachusetts tallied 8 percent of its renewable-energy portfolio from wood-powered biomass. That’s down from a high of nearly 49 percent in 2007.

There has been international debate over the sustainability of biomass. England and many European nations have embraced wood power as a green replacement for coal. A large portion of the fuel is shipped to Europe as wood pellets made from U.S. forests, and wood-pellet mills are proliferating across the southeastern United States to help meet the growing demand. As demand increases, the source for fuel has expanded from tree trimmings and lumber residue to whole trees.

Some countries, however, such as the Netherlands, are now pausing plans for woody biomass as they review the emissions and other environmental impacts.

Rhode Island’s legislation would incrementally elevate the RES to about 38 percent of the state’s overall power mix by 2035. Environmental groups are pushing for an extension of the RES program without restrictions on woody biomass. During a recent House hearing, the RES was praised for helping meet climate-emission goals. On paper, at least, the RES will do that, because the carbon dioxide emissions from wood aren’t counted in emissions in programs such as the Regional Greenhouse Gas Initiative.

Larry Chretien, executive director of the Mass Energy Consumers Alliance, said it’s worth considering amending the legislation. But he predicts that the future of biomass will be crowded out by the influx of new solar- and wind-energy projects. His organization, which delivers renewable energy to electric customers in Massachusetts and Rhode Island, estimated that 4,234 megawatts of new wind power are proposed for New England, all of which can qualify for RES programs.

Meanwhile, wood-burning power plants are dying off. Two of the four woody biomass plants in Maine that provide power to Rhode Island have recently shut down because of low natural-gas and oil prices and stricter RES standards in Massachusetts and Connecticut.

“We think sources like biomass will become less important over time,” Chretien said. “We know for a fact the large majority of renewable-energy projects proposed for New England are wind and solar.”

The bill remains in committee.