Hawaiian Electric has plans to build power plant on post

Hawaiian Electric Co. is proposing to build a quick-starting, 50-megawatt power plant at Schofield Barracks that could help stabilize Oahu’s electrical grid as the utility works to absorb increasing amounts of variable power from solar and wind energy sources.

The project would be tied into the HECO grid. But the power it produces could be "islanded" to exclusively serve Schofield Barracks and Wheeler Army Airfield in the event HECO’s Oahu electrical distribution system is knocked offline.

HECO outlined its plans in an environmental impact statement preparation notice filed with the state office of Environmental Quality Control on Dec. 23 and made public Wednesday. HECO would own and operate the facility, which it expects to be operational by the end of 2017.

The power plant would consist of six reciprocating engine-generator units capable of burning biofuel. The facility will be more responsive that HECO’s three base load power plants on Oahu that generate electricity using steam boilers that burn low-sulfur fuel oil, utility officials said in the filing.

The capability of the new units to quickly ramp up and down "makes them particularly helpful for maintaining grid stability as the amount of power from various renewable sources — wind and solar — increases over time," according to the filing. "In short, they complement, rather than compete with, other existing and anticipated renewable energy sources in the system."

In addition to serving Schofield and Wheeler, the power plant would supply electricity to the Army’s Field Station Kunia.

The power plant’s capacity "is sufficient to meet the three Army installations’ peak electrical power requirements for all operational needs, administrative functions, logistics and quality of life functions, thereby providing energy security for the installations if power from the normal source of electricity supporting these Army installations is interrupted," according to the filing.

HECO currently has access to about 1,600 megawatts of generating capacity on Oahu, but it will lose 113 megawatts of that when it deactivates its Honolulu Power Plant near Aloha Tower at the end of this month.

The Schofield power plant would be built on 10 acres leased from the Army. It would be connected to a 46-kilovolt HECO transmission line via a 6-mile overhead power line, according to the filing.