Federal and state officials gathered to applaud the groundbreaking of an electric power generation plant at Schofield Barracks on Monday that will be run on 50 percent biofuel and 50 percent fossil fuel.

The 50-megawatt plant has to get at least 50 percent of its fuel supply from biofuel to satisfy federal requirements.

“This mixed-fuel facility is a small step in the right direction towards Hawaii’s renewable energy goals, and for that Hawaiian Electric and the U.S. Army should be applauded,” said Marti Townsend, director of Sierra Club Hawaii. “But the reality is Hawaiian Electric needs to do significantly more right now. … This is good news, but in the context of what we really need, this announcement is definitely short of amazing.”

Townsend said Hawaii needs to avoid being subjected to “a future of volatile fossil fuel prices and climate disruption.”

Gov. David Ige, who attended the groundbreaking, said the new plant is a move in the right direction.

“The fact that the plant is 50 percent biofuel means that the plant is using 50 percent less in fossil fuels,” Ige said. “That is a positive step toward our goal of achieving 100 renewable energy by 2045.”

Ige said Hawaii does not produce enough biofuel for the plant to run only on the resource.

“We need to build the capacity for a biofuel industry in Hawaii so that plants like Schofield’s can run on 100 percent biofuel,” he said.

Ige said the state may be closer to producing larger quantities of biofuels than originally planned due to companies like TerViva, which grows biofuel crops on 300 acres on the North Shore of Oahu, and Hawaiian Commercial &Sugar Co. on Maui committing to use some of its land to grow biofuel crops.

Hawaiian Electric Co., the state’s largest utility, said it expects the plant to be up and running by spring 2018. HECO will develop and operate the plant on an 8.13-acre lot it rents from the Army.

Katherine Hammack, assistant secretary of the Army for installations, energy and environment, said Oahu needed the plant as it works to bring more renewable energy resources, such as solar and wind power, onto the grid.

“The island couldn’t put more renewables up until this was built,” Hammack said. “That is one of the challenges; the island of Oahu needs fast-start base load generation so you can put up more renewable intermittent resources. … We have about 25 megawatts (of solar power) on the houses on base, and one of the things that we talked to Hawaiian Electric about is if you get too many renewables and not enough fast-start generation, the grid can go unstable.”

Wind and solar energy resources are considered intermittent because changes in weather can cause dramatic fluctuations of generation at the facilities. The Schofield plant’s generators will be capable of quickly starting up, shutting down or changing their output in response to sudden changes in solar and wind energy resources, which provide varying levels of energy depending on weather, time of day, cloud cover and other factors.

Christine Harada, federal chief sustainability officer for the White House Council on Environmental Quality, said the Schofield facility helps get the federal government closer to its goal of reducing greenhouse gas emissions from 2008 levels by 40 percent before 2025. The goal — which includes 360,000 buildings and 650,000 fleet vehicles — was outlined in President Barack Obama’s Executive Order 13693.

“This project is a very shining example of the federal government not just paying some lip service, but really walking the talk and taking the lead on sustainable and environmental action,” Harada said.

The quick-starting facility will be built 8 miles from the ocean, making it less susceptible to damage from tsunamis than facilities closer to the water.

Alan Oshima, president and CEO at HECO, said the plant will better prepare the island for emergencies.

“When this is built, its significance is beyond just the renewables,” Oshima said. “It is the first plant on high ground in Hawaii. With the sea level rise that we are all contemplating, the days of the past where we relied on ocean cooling power plants — we really have to rethink that. … This will really give us the ability to cope in a much better way than we are presently able to.”

In the event of an emergency, the Schofield plant will be able to isolate itself to Army bases in order to provide reliable power to the Army’s facilities in Central Oahu.

“In exchange for the land, the Army has the right to island this micro-grid to provide for itself,” Oshima said.

Oshima said when the Army disconnects its grid, it can also provide reliable electricity for neighboring communities and facilities such as Wahiawa General Hospital.