Anchoring Air Force Energy Goals
The farthest north facility of its kind at 61 degrees latitude, the Anchorage Landfill Gas-to-Energy Project at the Joint Base Elmendorf-Richardson is the largest green energy project amongst the U.S. Air Force’s Pacific operations. Its existence is the result of collaboration by the Municipality of Anchorage, Doyon Utilities and JBER, and after just one year of successful operations is being expanded.
The pieces to the project puzzle had been falling together for many years before it was a done deal. The first piece was passage of the Energy Policy Act of 2005, which required federal facilities to increase renewable energy consumption to at least 7.5 percent by 2013. In 2006, because it was exceeding the threshold limit for nonmethanogenic organic compound emissions, the Anchorage Regional Landfill brought on line a gas collection system, which it tested and operated for three years. During that time, Doyon Utilities purchased the utility infrastructure—electrical, water, sewer and natural gas distribution system— on three Army bases in Alaska: Ft. Wainright, Ft. Greely, and Ft. Richardson, which have merged into a joint base facility that is now run by the Air Force, says Robert Zacharski, JBER site manager.
In 2010, the Municipality of Anchorage put out a request for proposals to use gas generated at ARL, and Doyon Utilities was selected. A contract was signed in 2011, and the power plant became fully operational just over one year later.
The landfill gas collection system draws from 87 acres of landfill and consists of 36 vertically drilled wells, 21 horizontal collector wells that range between 60 and 120 feet deep, and eight interconnections with the leachate system. “We purchase methane from the municipality of Anchorage,” Zacharski explains. “A vacuum is applied to the landfill—if we get too much we’ll flare off the excess—and we bring our portion through a mile-long [low-pressure] pipeline to the base’s generating building.”
There, five 1.4 MW GE Jebaucher gas engines produce power that is tied into the base’s distribution system, enough electricity to meet half of the power demand for the Ft. Richardson side of JBER, or 100 percent of its emergency backup power.
The facility is currently undergoing an expansion—which was part of the initial plan—but it’s happening much earlier than expected, as there are few landfills of this size operating in similar climates to use as baselines for methane generation. “Initially we put in four 1.4 MW generators, totaling 5.6 MW, and we’re just commissioning the fifth unit right now, which will put the plant at 7 MW. Our project financial model underestimated the gas generation in the landfill, so once we started operating it became apparent we could push up the fifth unit installation from year five to after year one.”
A sixth unit is scheduled in five years, but Zacharski says gas use will be maxed out at that point.
Operation, Maintenance and the Military
With an operation and maintenance budget of $639,000 for the power plant, gas processing facility and transmission pipeline, Doyon Utilities uses subcontractors as well as in-house personnel. The system is run by one operator, 40 hours a week, who can monitor it remotely to check for abnormalities, according to Zacharski.
Surprisingly, operational challenges caused by the harsh climate have been minimal. “The gas supply remains very consistent between winter and summer,” Zacharski says. “You might think digestion would slow down in winter, but we haven’t found that’s the case.”
Initially there were some issues with the outer piping and freeze ups, but it was remedied this summer. “We had some teething problems, but it hasn’t been really different operating a similar plant [elsewhere],” Zacharski says. One specific climate-driven innovation that the project partners believe is the only application of its kind and will reduce future maintenance and repair costs is installation of preinsulated HDPE (high-density polyethylene pipe) with electric heat trace, to ensure the pipeline won’t become blocked with frozen condensate. In this case, the heat trace is a thin wire along the bottom of the pipe that can generate heat when needed.
While the climate overall hasn’t been too different from developing a project in more temperate regions, doing so on a site owned by the military may pose more challenges than the typical model, according to Zacharski. “The Air Force has different ideas of what an acceptable payback is, so you have to structure your finances to meet those expectations, and that may be difficult to do,” he says. “They want a pretty rapid turnaround.”
Additionally, approval processes are lengthy. “Getting a notice to proceed to build a plant and making a schedule becomes challenging, when you don’t know when you’re going to get the go-ahead to start construction, or even if the project will go. On the private side of the fence, you have that control, but you lose a little of that on a military installation.”
For the $35 million project, Zacharski said cash flow will turn positive in about four years. It is expected to result in a savings to JBER of $32 million in power costs over the initial contract period and $73.6 million over the potential life of the project, and the municipality will annually take in $1 million from gas sales, nearly $52 million over the life of the project.
“In general, this has been a very successful project,” Zacharski adds. “It utilizes waste gas that was being flared, producing no value to anyone, to increase Doyon’s, the municipality’s and the Air Force’s bottom line.”
Author: Anna Simet
Managing Editor, Biomass Magazine