When compact fluorescent light bulbs first started appearing on store shelves in Hawaii a decade ago, they were largely considered a novelty item with a prohibitively high price tag.

Wary consumers weren’t sure whether the energy savings promised by the odd-looking bulbs made them worth the extra cost, which at the time could be as much as 10 times an incandescent bulb.

Since then, however, a sharp drop in CFL prices combined with rebate programs and improved marketing campaigns have dramatically boosted sales and made CFLs a mainstay in the state’s campaign to reduce energy consumption.

Hawaii Energy estimates of the 30 million light sockets in homes statewide, about 5 million, or 17 percent, have a CFL installed. There is plenty of room to generate continued efficiency gains from CFL installations.

The company running the energy conservation program has a target of selling 1.5 million CFLs in the fiscal year that ends June 30 — a goal that would save 39 million kilowatt-hours of electricity, or 61,000 barrels of oil. With 878,000 bulbs sold through Jan. 17, the program is on track to exceed its target.

After accounting for rebates, which range from $1 for regular CFLs to $5 for dimmable ones, the energy-efficient bulbs provide consumers annual savings of $24 each when compared with traditional incandescent bulbs, according to Hawaiian Electric Co. The utility estimates that CFLs use anywhere from 60 percent to 75 percent less electricity than incandescent bulbs.

Including the rebate, a three-pack of off-brand, 75-watt equivalent CFLs was available at Walmart last week for $4.50, or $1.50 per bulb. A name-brand two-pack of 75-watt incandescent bulbs across the aisle was priced at $2.50, or $1.25 a bulb.

Different manufacturers make different claims for the life spans of their CFLs. HECO estimates the average life span of a CFL at 8,000 hours, more than eight times the 750 hours offered by a comparable incandescent.

The CFL rebates come out of the "public benefits fund" paid for by utility ratepayers. The average HECO customer pays $3.57 a month into the fund.

The fund, along with other energy-saving efforts, is administered by the Hawaii Energy conservation and efficiency program, which took over the responsibilities from HECO in 2009. Hawaii Energy streamlined the rebate program for CFLs, which was previously a cumbersome process involving coupons and mail-in rebates. Hawaii Energy worked with retailers to have the rebate built into the price of the CFL on the store shelf.

Even though CFLs use about 75 percent less electricity than incandescent bulbs, there are some downsides that could make further market penetration more difficult.

The chief concern is that CFLs contain a tiny amount of highly toxic mercury. Although the mercury level in a CFL is less than what is in a can of tuna, the Environmental Protection Agency classifies the bulbs as household hazardous waste and has detailed guidelines on its website on how to dispose of them (www.epa.gov/cfl/cflrecycling.html).

The Honolulu City and County’s Department of Environmental Services says CFLs, as well as fluorescent tubes, can be brought to the city’s Household Hazardous Waste bimonthly event by appointment. Alternatively, consumers may also wrap bulbs in newspaper and dispose of them with their regular household rubbish, according to the department’s website (www.opala.org).

For a broken CFL, the EPA recommends that everyone leave the room for five to 10 minutes before opening a window or door to the outdoors. The broken materials should then be put in a sealed container and placed in a trash container outside. If practical, the room where the bulb broke should be aired out "several hours," according to the EPA’s website.

Despite Hawaii Energy’s efforts to promote CFLs and other energy-saving measures, the state is still falling behind in its push to reduce energy use through conservation and efficiency by 4,300 gigawatt-hours, or 30 percent, by 2030.

R.W. Beck, the contractor hired by the PUC to manage the Hawaii Energy program, came within 97 percent of its target set for residential energy reduction and 81 percent on the commercial side in its first fiscal year, which ended June 30.

However, when those results are projected out to 2030, the trend falls far short of the target. At the current pace, the program is on target to reduce consumption by just 1,202 gigawatt-hours, or 7 percent, by 2030.

"We’ve got our work cut out for us," said Ray Starling, program manager for Hawaii Energy.

One key area Hawaii Energy plans to focus on is to increase conservation efforts among commercial utility customers, who lagged their residential counterparts in the 2009 program year. Hawaii Energy offers a wide range of rebates to businesses for things like high-efficiency lighting and air conditioning, window tinting and energy-efficient equipment.

Because of the lengthy economic downturn and tepid recovery, many cash-strapped businesses have been reluctant to put money into energy-efficiency measures that might not provide an immediate return on their investment, said Michael Chang, deputy program manager.

However, businesses should look at improving their energy efficiency as a way to protect themselves from rising oil prices, he said, recalling the crude spike in 2008 that forced many Hawaii businesses to close.

Some of the business owners whom Hawaii Energy has talked to say they are waiting for the economy to improve before they take on any capital improvement projects, Chang added.

"But they don’t understand that if you don’t take some kind of action, you are increasing the likelihood of your failure."

In an effort to bring more businesses into the program, Hawaii Energy has abandoned its one-size-fits-all approach to commercial utility customers and is now working more closely with the companies to tailor programs to fit their specific circumstances.

"Now we’re saying if you’ve got a project that you want to move on but you’re not just quite ready because the money’s not there, come see us; tell us what you need, and we will find a way to make something happen," Starling said.