MARION — This city has been trying for some time to make something of nothing — or, more precisely, to turn trash destined for the landfill into energy.
In that regard, both Marion city officials and a Marion-centered advocacy group, wastenotIowa, have been promoting Florida firm Plasma Power LLC and its plan to build a plasma-arc power plant in Marion or the metro area to zap garbage into gas.
In the meantime, though, the mainstay in the local world of garbage, the Cedar Rapids/Linn County Solid Waste Agency, has decided to invest in some energy innovation of its own at its Site 2 landfill on Marion’s northeast border.
The Solid Waste Agency is in the final stages of building a $3.2 million system that collects methane created by decomposing trash at the agency’s Site 2 landfill and pipes it to and through an internal combustion engine that drives a generator and produces electricity.
By February, the system will be up and running with the electricity fed into to a nearby substation and purchased by the Central Iowa Power Cooperative. The system will produce 1.6 megawatts of electricity, an amount sufficient to power an estimated 1,300 homes, the agency says.
As a bonus, the heat from the system’s internal combustion engine and generator will be piped to the agency’s new Resource Recovery Center, now under construction at the Site 2 landfill. The agency says the heat will save the agency an estimated $90,000 in propane fuel costs a year.
The landfill-gas-to-energy system also greatly reduces most of the harmful greenhouse gas emissions that come when methane is released directly into the atmosphere.
“The Solid Waste Agency is very excited to see this project come together,” spokesman Joe Horaney says. “We are creating renewable energy, helping the environment and saving money by capturing waste heat for another use. It is a truly sustainable effort.”
Horaney notes that revenue from the tipping fees paid by municipalities and commercial haulers that use the agency’s two landfills is paying for the bulk of the landfill-gas-to-energy system’s cost. A $650,000 renewable energy grant through the State Energy Program also is helping.
Brian Harthun, an agency consultant and senior engineering manager at Foth Companies in Cedar Rapids, says the renewable-energy grant was vital in helping to make the economics of the energy project work.
Horaney estimates that the system will generate about $240,000 a year for the agency after expenses, an amount that will cover the agency’s initial capital costs in about 10 years.
The Metro Waste Authority’s landfill in Polk County and the Central Disposal Systems Inc.’s landfill outside Lake Mills have landfill-gas-to-energy systems in place. The Metro Waste Authority, which put its system in place in 1994, is planning to double its output to 13 megawatts of electricity or enough to power an estimated 10,000 to 12,000 homes, Reo Menning, the agency’s public affairs director, reports.
IOWA CITY SYSTEM
In Iowa City, Dave Elias, superintendent at the city of Iowa City’s Landfill, says his operation has a system of pipes in place to collect methane and send it to a central location where it is burned or flared into the atmosphere.
The same flare setup is used at the Cedar Rapids/Linn County Solid Waste Agency’s Site 2 landfill north of Marion and at its Site 1 landfill, known as Mount Trashmore near downtown Cedar Rapids, which reopened to take in flood-recovery debris in 2008 and is set to close again.
Elias and Harthun note that flaring methane, which Elias says converts the gas into carbon dioxide, reduces the greenhouse-emission impact by 98 percent compared to the direct venting of methane into the atmosphere. In fact, the landfill gas-to-energy system coming on line to replace the flare at Site 2 north of Marion will be slightly less efficient because the engine and generator in the system come with their own environmental emissions, Harthun explains.
In Iowa City, Elias says it has not been financially sensible to install a gas-to-energy system because the landfill isn’t close enough to a utility’s infrastructure and because the price offered for the electricity has been too low.
As a result, Elias says the Iowa City Landfill now is looking at a concept where it provides energy to an industrial entity that might locate next to the landfill.
Such a possible arrangement is a reminder that the Cedar Rapids/Linn County Solid Waste Agency has had a history of trying to figure out what to do with landfill-generated methane. (story continues below photo)
Back in 1995, the agency, which formed in 1994 and is comprised of the governmental jurisdictions in Linn County, signed an agreement to directly pipe methane about two miles from the Site 1 landfill to Alliant Energy’s coal-fired electric plant on C Street SW. By 2005, EnviroGas LP, a Chicago entity contracting with the Solid Waste Agency, signed a deal with Penford Products Co. to send the methane there.
Problems, though, prevented Penford from being able to use the methane, and then the flood of 2008 hit, damaging the piping system.
The Solid Waste Agency and EnviroGas have been in litigation over their contract, with a binding arbitration session slated for December.
Once an arbitrator settles the dispute, the Solid Waste Agency will have to decide what the future of methane from the Site 1 landfill might look like. For now, the methane is being collected and flared.