Pacific Biodiesel-fueled generating station powers up microgrid of 3 US Army installations in Hawaii

The Schofield Generating Station on the Hawaiian island of Oahu, which came online in 2018, will be able to power up a utility-owned microgrid consisting of three U.S. Army installations in central Oahu during a major power outage, particularly in hurricane season.

The inaugural test of the Schofield Generating Station’s microgrid capabilities, conducted by Hawaiian Electric and the Army, affirmed that if power is lost at Schofield Barracks, Wheeler Army Airfield and Field Station Kunia—all critical lifelines during an emergency—the three installations can be islanded and powered with 100 percent locally and sustainably produced biodiesel that powers the Schofield-based power plant.

In late 2017, before the 50-megawatt Schofield Generating Station came online, Hawaiian Electric and Pacific Biodiesel signed a fuel supply contract for the power plant. Pacific Biodiesel operates a 5.5 million gallon per year biodiesel production facility on the Big Island of Hawaii.

“Schofield Generating Station has been providing 100 percent renewable, reliable energy to our customers for several years now,” said Jack Shriver, Hawaiian Electric’s director of project development. “This successful test adds ‘resilient’ to that list. Schofield Generating Station can keep critical infrastructure operating during a major outage, hastening recovery.”

Bob King, president and co-founder of Pacific Biodiesel, told Biobased Diesel Daily that the Schofield Generating Station can go from zero to 50 megawatts of power production in two minutes or less.

“The beauty of this power plant is that it’s a quick-response plant,” King said. “And with multiple engines, it can come online at full efficiency in 8-megawatt increments.”

Hawaiian Electric says the Schofield Generating Station is the only power plant on Oahu that is located inland, protected from the potential impact of storms, tsunami and rising sea levels. Even though the plant is capable of operating on diesel fuel or biodiesel, the utility said since commissioning it has operated on 100 percent biodiesel from Pacific Biodiesel.

A 50-megawatt power plant running at full capacity would require a lot more biodiesel, however, than Pacific Biodiesel could supply.

“So how they run this plant,” King explained, “is to keep it offline most of the time, utilizing wind and solar, and just bring it online if the wind or solar hesitates during the day, and to meet the evening peak after the solar sites go down.”

The power plant is usually run three to five hours a day, according to King. “They typically order about 175,000 gallons per month,” King said, adding that the heat rate is about 14.5kWhr per gallon of biodiesel.

As part of the recent test, the Army shut off power to Schofield Barracks, Wheeler Army Airfield and Field Station Kunia May 22 early in the morning. “In less than an hour, Hawaiian Electric carved a microgrid out of its subtransmission system and restored power to the installations using Schofield Generating Station as the primary source of power, supplemented by the Army’s rooftop PV on the bases,” stated Hawaiian Electric in a press release. “Upon completion of the 36-hour test, the Army again shut down the bases and Hawaiian Electric restored normal grid power.”

The utility added that, although the generating station has been providing valuable service to all Oahu customers since it came online three years ago, the test proved the facility’s additional and unique resilience capability—and not only for the Army.

“Wheeler Army Airfield is home to Hawaii Army National Guard helicopter units and the Civil Air Patrol, and during emergencies can be used as a Federal Emergency Management Agency air access and staging site,” Hawaiian Electric stated. “The ability to provide utility-grade microgrid power to these facilities during an emergency could significantly improve disaster response for the entire state of Hawaii.”

Jack Surash, an assistant secretary of the Army, said, “The Schofield Generating Station provides reliable access to energy during power disruptions and ensures Army readiness. This test demonstrates the power of microgrid capabilities to successfully isolate from the main Oahu grid when needed and deliver enhanced energy resilience to benefit the Army.”

Keith Yamanaka, energy chief for the U.S. Army Garrison-Hawaii, said, “At the core, the success of the Schofield Generating Station project has been the ability for the Army and Hawaiian Electric to work together. This collaboration developed, executed and operationalized energy resilience for the state of Hawaii and the Army. This successful test of the [generating station’s] capabilities is the culmination of an unprecedented amount of coordination and joint efforts between a utility company and a Garrison.”

Schofield Generating Station is located on eight acres at Schofield Barracks that the Army leases to the utility. In return for the value of the 35-year lease, Hawaiian Electric guarantees the Army energy security, ensuring it will be able to restore power to the three installations within two hours is a power outage were to occur. The lease requires Hawaiian Electric to conduct a one-time “full system test” of this capability to prove it can be accomplished, which was completed last month.