by Joni Astrup
Great River Energy’s garbage processing plant used to be one of the Elk River Landfill’s best customers.
Now the plant in Elk River can go several months without sending a single load of trash to the landfill.
Steve Vrchota, leader of plant operations at the facility, said they landfilled just .4 of 1 percent of the 245,000 tons of garbage that went through the plant in 2012.
“It’s almost zero,” he said.
Garbage from Sherburne and surrounding counties has been processed into fuel since the garbage-to-electricity project went online in 1989. Currently garbage from Sherburne, Anoka and Hennepin counties is trucked to the processing plant at 10700 165th Ave. in Elk River. There it is sorted, recyclable materials are pulled out, and the garbage is processed into a fluffy fuel known as refuse-derived fuel or RDF. That RDF is then trucked to the Great River Energy power plant at 17845 Highway 10 in Elk River, where it is burned to generate electricity.
The power plant produces approximately 29 megawatts of electricity — enough to provide power to about 25,000 homes.
For the first 20 years of the project, about 12 percent of the garbage that came into the processing plant ended up being landfilled. But that began changing after GRE purchased the facility in 2010.
One improvement was the purchase of a shredder to break down bulky items like mattresses, box springs and pallets. Shredding allows the plant to recycle things like steel in those bulky materials and process the rest into little pieces of RDF.
In addition, garbage that is run through the plant but rejected as RDF is now re-run a second time at a slower speed and with modified settings. That allows a good portion of that material to become RDF. What’s left contains enough metal like aluminum and brass that it can be sold to a metal refiner, Vrchota said.
As a result of the changes, currently about 95 percent of the garbage taken to the plant ends up as RDF, 4.5 to 5 percent is recycled and less than 1/2 of 1 percent is landfilled, Vrchota said.
Reducing the amount of garbage going to the landfill helps the plant be as competitive as possible with its tipping fee — the amount haulers pay to dump garbage at the plant — and helps reduce expenses that ultimately affect the cost of electricity.
“Since we’re a power company, our end goal is to make our electricity competitive with any other way of generating that same power,” Vrchota said.
Electricity produced by burning RDF is more expensive than electricity from coal-burning power plants, but is comparable to electricity produced at other biomass facilities and to some wind farms, he said.
Nationally, Vrchota said 92 percent of garbage goes to landfills with 8 percent going through processing facilities like the one in Elk River.
The Elk River plant is currently handling about 1,000 tons of garbage a day. It has the capacity for about 1,500 tons per day. It is on budget to receive 270,000 to 280,000 tons of garbage this year, Vrchota said.