With all the concern about dwindling natural gas supplies in Alaska’s Cook Inlet basin, and the talk about ways to spur new exploration, one small but promising gas field often gets overlooked.
This field produces 1.5 million cubic feet of gas every day. And if the math is right, it could keep producing that much or more for the next 60 years. It sits near existing infrastructure. It doesn’t require seismic surveys. All the wells have been drilled.
The field is the Anchorage Regional Landfill.
The millions of tons of decomposing garbage in the landfill naturally release enough gas to create between three and five megawatts of power, enough to run thousands of homes throughout Southcentral Alaska.
But right now, every cubic foot of gas produced from more than 50 shallow wells at the landfill runs through an on-site pipeline grid into a tall black tower, where 1,600-degree flames incinerate it and spew what’s left into the atmosphere.
Some believe this is the most environmentally sound way to manage the large accumulations of gas present at just about every modern landfill in the world.
But others, like Mark Madden, believe it’s time to make something with that gas.
Madden is the director of Solid Waste Services for the municipality of Anchorage, which owns the landfill outside of Eagle River, and he said the landfill is now productive enough to generate a significant amount of gas or electricity.
For years, city officials have explored various options for turning the landfill into a commercial project. Now, with a year and half of data, Madden and others are starting to look for offers and following business leads.
“There’s a fair amount of interest in this project,” Madden said.
Not for producing gas, yet
Despite the wells, the pipelines and the flare, this gas production facility at the landfill was not created for producing gas. It was created for reducing emissions.
Landfills are naturally ripe with gases.
In the cramped, oxygen-free surroundings inside the landfill, bacteria feast on organic material found in regular trash. This decomposition releases methane, carbon dioxide, a selection of other gases and a range of “non-methane organic compounds.”
The conversion process takes only a few years, but continues as long as new trash gets added to the pile. Currently, the Anchorage Regional Landfill accepts around 1,200 tons of trash every day, and will ultimately hold around 20 million tons at full capacity.
Even after the expected close of the landfill in 2043, the underground bacteria will continue eating the old trash and burping out gas for decades, eventually peaking, declining and becoming depleted like any other oil or gas field.
The U.S. Environmental Protection Agency estimates that municipal landfills account for nearly a quarter of all human-related methane emissions in the United States, and requires the larger landfills to manage those emissions.
The Anchorage Regional Landfill grew past that threshold around three years ago, and completed the gas capture system in October 2006.
The amount of gas produced at a landfill depends on a variety of factors, from the type of trash buried inside, to the amount of moisture in the landfill to the temperature.
Madden points to a collection of models estimating how much gas the Anchorage Regional Landfill should be able to produce between now and the end of the century.
One chart shows a curve starting at the opening of the landfill in 1987, growing to a peak around the expected close of the landfill in 2043 and gradually declining over the following three decades.
While that curve is just common sense, the actual production figures associated with it are best guesses. With the new facility, Madden and others at the landfill now have 18 months of actual data to go on.
“Everything is running according to the models,” Madden said.
Gas originally a problemThroughout the 1970s and 1980s, engineers studying the old city landfill at Merrill Field assumed Alaska was just too cold to produce gas without an expensive heating source. Madden helped prove that the landfill produces its own heat underground, which is trapped by the insulating effect of snow cover.
In the late 1980s, testing showed significant amounts of methane migrating out of the landfill. Like their counterparts around the country, local landfill officials at first saw that gas as a potential problem: either a substance capable of contaminating local air and water supplies, or fuel for a large explosion or underground fire.
The tide began to turn nationally in the mid-1970s when the Palos Verdes Landfill in Rolling Hills, Calif., started selling pipeline quality gas to a local utility in 1975. Several similar projects quickly followed through the rest of the decade.
Over the past two and a half decades, landfill owners across the country have seen the gas at their facilities as an opportunity, according to Tom Frankiewicz with the Landfill Methane Outreach Program, a division within the U.S. Environmental Protection Agency.
“Just in that timeframe, there’s a lot more awareness. … There’s been a huge shift,” Frankiewicz said.
With the ever-increasing interest in new sources of energy and increasing pressure to reduce emissions, landfills have been making good on the promise of “free fuel” by selling their landfill gas for various modes of power production.
Between 1981 and 1996, the number of landfill gas recovery projects in the United States jumped from four to around 130, according to the U.S. Energy Information Administration. Today, according to the EPA, more than 450 landfill projects in 43 states are producing around 77 billion cubic feet of landfill gas for direct use and 11 billion kilowatt hours of electricity every year.
That electricity and gas is currently powering or heating nearly 1.5 million homes through projects with varying degrees of public and private involvement. But the Landfill Methane Outreach Program, which facilitates those business partnerships through data collection, also counts 535 “candidate” projects that could double the existing supply.
Those numbers help explain the interest in landfills, Frankiewicz said.
“Just on their own, outside of the environmental benefit, these projects are economical,” Frankiewicz said. “That’s always been the foundation for moving forward.”
Currently, Alaska is one of seven states without a landfill energy project in operation.
Although Frankiewicz counts 18 “major” landfills in Alaska, only the Anchorage Regional Landfill is considered large enough to support a full-scale project. The EPA estimates the local landfill could produce around 5 megawatts of power from its gas.
Gas couldn’t offset declinesGas produced from the landfill would add another local supply source, but couldn’t offset the anticipated production declines in the Cook Inlet.
But at 500 million cubic feet per year and the ability to nearly double that at peak production, the Anchorage Regional Landfill qualifies as a small to medium size field when compared to others in the Cook Inlet.
It’s nowhere near as large as Beluga River and North Cook Inlet, two of the most productive fields in the Cook Inlet, which produced 55 bcf and 38 bcf respectively in 2006, according to the most recent state figures.
But at the projected peak production of around 1 bcf per year, the Anchorage Regional Landfill would be more productive than some 15 existing units in Cook Inlet.
The declining legacy field Middle Ground Shoal, for example, produced only 300 million cubic feet of gas in 2006, while the newer Kasilof field produced 865 million cubic feet in 2006, its first year of production.
Even at full production, though, the annual output of the Anchorage Regional Landfill could only supply a few days of regional demand.
Is it renewable or not?Even with its growing popularity around the country, landfill gas sometimes falls between the cracks, at least in the dictionary.
When it comes to providing tax credits or other incentives for fuel alternatives, some argue against including landfill gas along with other renewable sources of energy, like solar or wind power.
That’s because while the gas inside a landfill technically “renews” itself as long as new trash is added to the pile, it’s still the same methane and carbon dioxide classified as greenhouse gases that trap heat in the atmosphere.
The flaring mechanism in place at the Anchorage Regional Landfill is designed to reduce emissions of methane, the more potent of the two gases, and some who oppose landfill energy projects believe this is the best way to manage that methane until a day when landfills stop accepting organic materials.
So far, there have been no major complaints in Alaska, though. The Renewable Energy Alaska Project includes landfills along with its more recognizable portfolio of renewable energy sources like wind and solar power.
The major obstacles in Anchorage have been science and money.
Landfill looking for partnersLocal landfill managers say the science is proven. They just need startup cash.
A power plant to turn the gas into electricity would require a $4 million to $6 million investment. To sell the gas directly would require additional facilities.
Madden said the municipality doesn’t want to build and run the facility itself, preferring instead to hire a contractor to design, build and operate the facility, or partner with a private developer. The landfill has two unused acres available for a power plant.
U.S. Rep. Don Young, R-Alaska, recently added language to an appropriations bill that would have given $750,000 to the Anchorage Regional Landfill to go toward transmission lines and generation facilities to turn the landfill gas into electricity. That appropriation hasn’t been approved.
Madden hoped some of the energy proposals floating around Juneau during the on-going special session would dedicate money for the landfill, but that didn’t happen either.
To make an economic project, the electricity produced through the Anchorage Regional Landfill must beat the “avoided cost of power,” or the amount area utilities currently pay to produce or buy electricity. By federal regulation, electric utilities must buy from qualified third parties who meet that price.
The avoided power cost at Chugach Electric Association, which serves much of Anchorage, is around 5.3 cents per kilowatt hour. The Matanuska Electric Association has a higher avoided cost of power, because it currently buys all of its electricity from Chugach, and so Madden hopes the landfill can compete.
But Madden ultimately believes the landfill offers a great return on investment.
“It will pay for itself,” he said.