Methane to megawatts

Hiland Road gas to fuel state’s only landfill plant


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Alaska’s first landfill gas power plant is slated to fire up this year near Eagle River.

No other landfill plant in North America — maybe the world — currently operates this far north.

But despite the Anchorage Regional Landfill’s location at the end of the chilly Eagle River Valley, the temperature at the trash pile’s core tops out at 100 degrees Fahrenheit all year.

Backers say the plant    will be cool only in the right ways — as a power source for Joint Base Elmendorf-Richardson that will also make money for the municipality using gas the landfill must now pay to burn off.

“It’s way cool. We’re going to make history with this,” said Stacy Scheevel, of the 673rd Civil Engineering Squadron at the base.

Anchorage has collected garbage at the Hiland Road site since 1987, after closing the Merrill Field landfill. There are now 8 million tons of garbage there. Every day, the landfill takes in another six pounds of garbage for every Anchorage resident.

That’s a lot of garbage — and a lot of methane, a potentially explosive gas created by trash-eating bacteria. Federal regulations require landfills like Anchorage’s to collect and combust it.

It currently costs the municipality more than $100,000 a year to collect and flare off methane, according to Mark Madden, Anchorage’s solid waste services director.

Once the plant starts producing power next January, the municipality could earn anywhere from $1.5 million to $2 million if natural gas prices hold, Madden said.

“Instead of having $100,000 in expenses to collect the gas, we’ll now have revenue coming in that will offset that cost,” he said.

The department plans roughly $40 million in upcoming landfill construction projects, so garbage fees probably won’t go down, Madden said. But the gas revenue should keep fees from rising as much as they would otherwise, he said.

The plant is located on base property at the southern end of the landfill.

Nearly 30 collection wells already pipe methane into a flaring building near the main entrance off Hiland Road. A 6,000-foot pipeline will run gas to the plant. Gas-processing modules will strip water and other compounds and the gas will be piped to generators. 

The plant is expected to start using landfill gas this fall and start full commercial operation in January, 2013.

 

Military megawatts

The plant’s power-producing capacity will be 5.6 megawatts — enough to power 6,000 homes.

The cost of the plant is estimated at $26 million. Of that, $2 million came from the state’s Renewable Energy Grant Fund. The rest is coming from Doyon Utilities LLC, the native corporation’s subsidiary with a 50-year contract to operate the base’s utilities.

Doyon got a $2 million grant from the state, and expects to receive another $6 million from a federal renewable energy grant, according to Tim Jones, director of administration. Doyon will finance the rest.

Right now, all the base’s power comes from Municipal Light & Power. The landfill plant will provide power to the Fort Richardson side of the base only, Jones said. It should be able to provide up to half Ft. Rich’s electricity needs in winter and perhaps all in summer, he said.

Military officials say the power produced will offset what the military would have to buy from the muni. Over the life of the project, that could add up to a $45 to $50 million savings, according to Scheevel, with JBER.

“The beautiful thing about this project is that it would have never been able to be done by the military itself because of the expense and the economy we’re in right now,” he said.

The plant will also help the base meet federally mandated goals. Starting in 2013, federal agencies will be required to use renewable energy sources to provide at least 7.5 percent of total electric consumption, according to Stephanie Nowers, communications director for the Renewable Energy Alaska Project.

The group, known as REAP, held a forum on the landfill gas plant earlier this month. To hear it, go to  http://alaskarenewableenergy.org/events/reap-monthly-forums/

 

Join the crowd

The Anchorage plant will become one of many similar facilities.

As of July, there were 558 operational landfill gas energy projects in the United States and approximately 510 landfills that were good candidates for projects, according to the U.S. Environmental Protection Agency’s Landfill Outreach Program.

Not everyone, however, is a fan of using landfill gas for energy.

Landfill gas is about half methane, half carbon dioxide, and a small amount of organic compounds, according to the EPA. Those compounds may contain contaminants, possibly including mercury or benzene, according to the Energy Justice Network, a national nonprofit based in Philadelphia.

So landfill gas isn’t as “green” an energy source as other true renewable sources such as wind or solar, the group says. Burning landfill gas is dirtier than burning natural gas, emitting more pollution per kilowatt hour, according to an EPA study cited on the group’s Web site. 

At the Anchorage plant, the moisture coming up with the gas will be extracted and treated at the municipal wastewater treatment plant, Madden said during the REAP forum. Carbon dioxide will be treated as part of the emissions coming out of the plant’s generators, which include air-quality controls.

The plant will use pollution-control devices to meet all of the standards required, he said in a subsequent interview.

 

Chill factor

Some landfill gas facilities are located in wintry states such as Michigan and Minnesota, but none in a place like Alaska where winter lasts six months.

Methane is produced by trash-eating bacteria that tend to slow down in the cold. Could our chilly winters put a freeze on methane-making?

The internal temperatures at the landfill range from 70 degrees about 10 feet down to about 100 degrees deeper down, Madden said. Some studies showed that it took two years to thaw out trash buried at 10 or 20 below zero. But that frozen trash accounts for only about 50,000 tons out of 300,000 tons of trash deposited in the landfill every year.

“It’s not a concern,” he said.

 

Zaz Hollander is a freelance writer from the Mat-Su. Contact her via email at editor@alaskastar.com

 

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