Canada’s Kyoto climate-change program contains a plan to give money to anyone who wants to generate electricity with methane gas produced by fermenting garbage.

David Anderson and Herb Dhaliwal present the Kyoto plan Nov. 21.

"As the plan indicates, we will increase our investment in innovative technologies for climate change, like greenhouse-gas capture and storage, and all forms of renewable energy," said natural resources minister Herb Dhaliwal during a recent press conference.

"In combusting the gas, we basically convert the methane to carbon dioxide and the science tells us that carbon dioxide is 20 to 21 times less harmful of a greenhouse gas than methane," says Pat McNally, director of utility services for the City of Ottawa. "Plus, it’s also safer because it’s less explosive."

Increasing levels of greenhouse gases are being blamed by many top scientists for causing the recent global warming trend.

"So for every one tonne of methane you destroy, it is the equivalent of keeping 21 tonnes of carbon dioxide greenhouse gases from escaping into the atmosphere," says Alain David, head of Environment Canada’s waste-prevention program.

"Methane is the second most critical greenhouse gas after carbon dioxide, and landfills generate quite a significant percentage of methane in Canada. So we need to capture as much of this gas as possible and even use it to generate electricity, when feasible."

According to Canada's Kyoto climate-change plan, released Nov. 21:

• Landfills generate about 24 megatonnes of greenhouse gas a year, primarily from methane.  This is equivalent of greenhouse gas emissions from more than six million cars.
• An estimated 25 per cent of landfill methane is recovered through active collection.
• The government estimates that its investment in methane capture at landfills will reduce greenhouse gas emissions by 2.2 megatonnes a year, and possibly by another eight megatonnes in the future.
• Canada’s target for Kyoto is to reduce its greenhouse gas emissions by 240 megatonnes by the year 2012. This amounts to about 50 megatonnes annually over the next five to 10 years.

From trash to treasure

"At Trail Road landfill site we’ve been collecting the methane gas coming off the garbage as it decomposes for the last 10 years," McNally says. "Now, along with the City of Ottawa and Energy Ottawa, we’re looking at the potential next step of burning or flaring the gas and using it for electricity."

McNally explains what happens at Ottawa's Trail Road facility:

1. Once a landfill reaches its capacity, the waste in it is crushed and compacted.
2. Holes are drilled deep into the landfill and a grid system of collector pipes is installed to capture the gas before it is released into the atmosphere. The pipes are surrounded by crushed rock, which allows the gas to be sucked into the pipes.
3. A plastic cap is installed on top of the pipe grid system to seal in the greenhouse gases.
4. The gases begin to rise from the garbage, as it slowly decomposes over time.
5. The gases are sucked into the pipes by a blower, located in the flare station.
6. The methane is ignited and burned, and converted into carbon dioxide.

There’s gold in garbage

Flaring isn’t the only option says Greg Clarke of Energy Ottawa, a private electricity supplier.

Methane captured at landfills is flared in towers like this one.

"It’s like a gasoline engine. You take a fuel with a high enough burn rate, such as methane. Then you need a modified engine, because it’s not the same quality as natural gas. You run it just like the engine in your car, but it’s a larger size. And this engine runs a turbine that produces electricity.

"Our estimates right now are showing that the Trail Road facility could generate between 3.5 to five megawatts, which could serve approximately 4,000 homes. It’s obviously a good investment opportunity."

With the City of Ottawa and the Trail Road landfill, Energy Ottawa is investigating the feasibility of the project — especially in light of the price cap put on electricity by the Ontario government. The plan is to begin construction of the project by January 2003, if the project can compete on the newly deregulated energy market in the province.

"It’s becoming very feasible but, as you know, our electricity is very cheap in Canada, maybe with the exception of Ontario," David says. "This makes it very difficult at times to create electricity, if the landfill isn’t a certain size, and if you can’t get a good deal with the hydro utilities. If you go to direct use, you have to compete against the price of natural gas. So, if you can find a large user nearby, it becomes very economical, because you don’t have to transport your gas all the way from Alberta. Instead the gas could be piped directly to large industries."

There are about 800 landfill sites across Canada, David says. Of these, 41 capture greenhouse gases. Only 16 convert the methane to electricity or sell it directly to nearby industry for boilers, burners, and other industrial processes. In Canada, only Toronto, Montreal, Waterloo, Ont., and Edmonton create electricity from methane.

The cost of this to the federal taxpayer is included in the $250 million invested through the Canadian Federation of Municipalities’ Green Fund.

While the idea of capturing methane from landfills and turning it into electricity seems brilliant to many, it is not without criticism.

Mike Kaulbars won Ottawa's 1995 Whitton environmental award and helps run the Peace and Environment Resource Centre.

He says, "Sure, on the surface, it’s good, if you choose to ignore the overwhelming problem of creating excessive waste at our landfill sites."

"Forty per cent of waste in landfills comes from organic material, which could be used for compost. And another 24 per cent could be reused or recycled. Sure, if you’re going to support the production of waste, then it’s a good idea, flare the methane into carbon dioxide which is 20 times less potent and spews less harmful greenhouse gases into the atmosphere.

"But we must be wary of any infrastructure which may provide disincentives to reducing the waste problem at our landfills, even to the point of providing a market for it."

Related Links Environment Canada’s Landfill Gas Utilization strategy Landfill Gas Industry Alliance: What is landfill gas? Peace and Environment Resource Centre’s online magazine Waste-line