The city is considering whether or not to expand its garbage-to-energy conversion program. Although the proposals arrayed before city officials are not yet public, it's already clear that leaving Honolulu with only the current H-Power capacity would be a shortsighted course of action.

Granted, it's only one of the waste-reduction ideas officials are pursuing, and that's a wise strategy.

The city has finally embarked on a curbside recycling program and is contemplating a plan for shipping refuse off-island as efforts to reduce the amount of garbage that must be sent to the Waimanalo Gulch landfill, already bursting at the seams. With the proposal to ban plastic shopping bags, there's hope that residents can be pressed to use fewer disposables, too.

But the concept of converting garbage to energy makes inroads toward achieving two O'ahu goals: waste reduction and energy production. With both landfill space and oil-based energy harder to secure, both goals are important components of Honolulu's sustainability, to use a word that's been branded on the public consciousness.

The current H-Power plant generates approximately 46 megawatts of energy by processing 2,000 tons of waste per day. That electricity serves the needs of 40,000 homes on O'ahu.

The hunger for energy is only going to grow, even with planned reductions in energy use, so it makes sense for Honolulu to begin ramping up.

And waste reduction could become an even more acute problem if the city Planning Commission or state Land Use Commission nixes the plan to extend the permit for the existing landfill.

The current method of burning the garbage and then filtering what comes out of the stack seems capable of meeting the increasingly stringent federal emissions standards into the future.

But officials need to confirm that H-Power methods still make sense for the long term, as opposed to newer "plasma arc" technology, which has been touted for lower ash production but has raised questions of reliability and costeffectiveness.

Additionally, federal regulations are becoming increasingly strict on emissions; the city must be certain to invest in filtration that will keep Honolulu in compliance.

Managing O'ahu's waste problem will only prove more difficult as the population grows. A more powerful garbage-to-energy capability seems an investment essential to an island municipality.