Aww man, the dream is dead.
Back in 2007, when the whole fight over where Grand Forks would, or rather could, build its new landfill, the City Beat did a story about the Fargo landfill, with some mention of a system that city uses to tap gas generated by putrefying garbage and convert it to heat for a nearby oilseed processing plant.
It was pretty cool then when Grand Forks looked into such a system for its old landfill. In 2008, I reported that UND’s Energy and Environmental Research Center had found that there may be enough landfill gas to pay for a 2-megawatt generator. The cost was estimated at $3.5 million, which means, at the electricity rate of the time, break even would occur in six years.
Well, that hopeful estimate prompted a more detailed study by Burns & McDonnell, the guys who designed the new landfill. Yesterday, their engineers came before the Grand Forks City Council’s service committee to say, essentially, that the city landfill is too small to generate enough gas to break even.
Here are a few reasons why:
- Rule of thumb says a 1.5-megawatt generator needs 450 cubic feet per minute of gas and a 2-megawatt generator needs 700 cfm. In 2010, the landfill is expected to generate 776 cfm, but only 209 cfm can be recovered. There are areas where the garbage is too shallow for landfill gas taps to work; they need about 20 feet of garbage. It gets worse. By 2030, there would only be 386 cfm with only 104 cfm recoverable. Fresh garbage is more putrid and generates more gas, stale garbage is almost done putrifying so there’s less gas.
- A system of pipelines and gas taps would cost $3 million. Add a boiler for heating and costs go up to $4.5 million. Add a generator or two and costs go up to $4.7 million. I’m not sure how they calculated maintenance and operations and electric rates, but the bottom line is that, over 20 years, the city would still be in the hole by at least $3.1 million with just the boiler and $3.7 million with the boiler and generator.
- Even with carbon credits at $12 per credit, which is the floor in proposed federal climate change legislation, that’s still not enough to break even.
That’s just heartbreaking. All that putrid gas gone to waste.
B&M consultants said the city could install a gas collection system at the new landfill and turn the landfill into something called a bioreactor, which is just a fancy word for adding water to the garbage to encourage microbes to putrify the garbage faster and make more gas. But, they said, it’ll cost a lot of money. How much they didn’t say.
