Ormat Technologies Inc. said it plans to drill a new well at its geothermal power plant on the Big Island to boost the declining supply of steam to the plant.

The plant, with 30 megawatts of generating capacity, had been generating 25 megawatts as recently as late last year following repair work, the company said in a news release. But output fell to about 17 megawatts last month as the steam supply declined.

"This decline is resulting in a monthly revenue decrease of less than $1 million based on current energy rates," the company said in a news release.

Ormat blamed the steam reduction on a "wellbore restriction" that reduced the flow from the existing wells to the power plant. Officials said they are pursuing several solutions, including plans to start drilling a new well in the next several days.

The drilling work of the new well and its connection to the power plant is expected to be completed by the end of the second quarter of 2010.

"This plan is intended to increase the available geothermal fluid and enable the power plant to generate at full capacity," according to the release. The project is expected to cost about $11 million, company officials said.

Officials also said they will use chemicals to clean existing wells. If that doesn't work, they said they would have to perform a mechanical cleaning, which would be more expensive and take more time.