Hawaiian Electric Co. is moving ahead with its plan to build a 110-megawatt generating plant at Campbell Industrial Park and has filed a draft environmental impact statement with the state for the $130 million project.

HECO's combustion turbine generating unit is projected to operate primarily from 5 to 9 p.m. weekdays to meet peak evening electricity demands, according to the company. The plant's cost will eventually be passed on to HECO's customers, said Peter Rosegg, HECO communications consultant.

The last rate increase was this past September, when HECO raised rates 3.3 percent — an average of $5 per residential household — to pay for upgrades on its current equipment. That increased the average residential monthly bill from $112.69 to $117.74, HECO said. It was the first rate increase since 1995, when rates were raised 1.3 percent.

The proposed plant will burn naphtha, a light petroleum fuel intermediate between diesel oil and gasoline, which HECO says is much cleaner than the fuel used at most HECO power plants. The project also includes a new 2-mile long 138-kilovolt overhead transmission line linking the plant to substations. HECO's draft EIS says a second 110-megawatt generating plant could be added if needed.

The plan is subject to approval by the state Public Utilities Commission.

Rosegg said yesterday the project would improve the electrical generation and transmission infrastructure on O'ahu and meet the system load growth. He said if the plant is not built, the island could experience power failures and rolling blackouts.

"This unit is designed to help us get through the peaking period," Rosegg said. "If we don't have it, as we get closer and closer on these peaks, we won't have any kind of a buffer and we could start having blackouts."

Environmental groups are trying to stop the project, saying O'ahu doesn't need another fossil-fuel-burning power plant.

"I think very few people on this island want to build yet another fossil-fuel power plant," said Jeff Mikulina, director of Sierra Club Hawai'i Chapter. It's "something that we are going to have to fuel for the next three or four decades when the price of oil is absolutely uncertain."

HECO said it hopes to have the plant operating by 2009. The utility first proposed a plant at Campbell Industrial Park in 1997.

According to HECO's draft EIS, the utility has a total net electrical generating capacity at all existing generating facilities of 1,642.6 megawatts. In 2004, customers used 1,327 megawatts of electricity, an increase of 3 percent from 2003, and demand is growing every year.

When announcing the proposed power plant last summer, the utility said the project would include several "community givebacks," including a 7 percent rate discount for customers in the area encompassed by ZIP code 96707. That would include 7,000 to 8,000 residents in Makakilo, Kapolei, Honokai Hale and Ko Olina.

Other initiatives include the construction of three environmental stations along the Leeward Coast to monitor air quality, a fish-monitoring program, and an underground water pipeline to move recycled wastewater from the city's Honouliuli Wastewater Treatment Plant to HECO's Kahe generating station.

Henry Curtis, director of the environmental group Life of the Land, said he is also opposed to the project and his group is a party to the PUC hearing.

Curtis said with the Legislature, Gov. Linda Lingle's administration and the business community all supporting moves to renewable energy, building a new fossil fuel power plant is a mistake.

"We are going to stop it," Curtis said.

Reach James Gonser at jgonser@honoluluadvertiser.com.