Recycling more of Honolulu's wastepaper into pulp products would benefit the environment in important ways, but incinerating such material to produce electricity remains a viable alternative, according to a new study commissioned by the city.

The analysis by consultant R.W. Beck does not recommend what officials should do next, but is meant to help them decide whether to create a residential recycling program or expand the H-Power garbage-to-energy plant.

Recycling wastepaper provides alternative raw material to paper manufacturers, thereby reducing the need for logging and production of "virgin" pulp products, the study noted. But such conservation mostly benefits other communities, where pulp and paper products are produced, the 50-page study found.

Recycling also "provides energy and greenhouse gas benefits greater than H-Power, but these benefits are geographically dispersed to locations off the island of O'ahu," according to the study.

Meanwhile, using wastepaper to help fuel the H-Power plant reduces the need to burn fuel oil to generate electricity, and "benefits Honolulu directly by reducing fuel costs and air emissions associated with fuel oil."

If only the impact on O'ahu is considered, H-Power "provides greater energy and greenhouse gas benefits compared to materials recycling," the study found.

Recycling would create more jobs on O'ahu, but H-Power generates greater overall economic value for Honolulu, according to the study.

Nearly 74,000 tons of the Island's wastepaper was recycled in 2005, according to data supporting the study. Recyclables are generally shipped to Asia or the U.S. Mainland.

The H-Power plant, at Campbell Industrial Park, burns about six of every 10 tons of trash the Island produces. It includes two huge boilers that produce steam to turn a turbine and generate electricity.

The city is considering whether to expand the plant's capacity by adding a third boiler, or to invest in an alternative trash-burning technology.

Officials also are planning a curbside residential recycling pilot project, and may eventually create an islandwide program.

The curbside plan has been controversial, however, because it would include a $10 monthly fee for homes that want to continue having trash picked up twice per week.

Mayor Mufi Hannemann has begun holding a series of meetings to present information about the options directly to residents, and to include their feedback in a comprehensive waste management plan.

Ken Kawahara, spokesman for city environmental services, said, "Right now, we're not fully leaning towards anything."

He added, "We want to get the community's input."

A key goal is to divert waste from the Waimanalo Gulch landfill in the future, he said.

"Whatever we can keep out of the landfill that doesn't need to go there is good for us and the environment," Kawahara said.

The landfill's operating permit will expire next year, and the city is seeking state permission to continue dumping trash there for at least 15 more years.

Reach Johnny Brannon at jbrannon@honoluluadvertiser.com.