The Toronto Zoo, the largest zoo in Canada and third-largest in the world, put out a request for proposals yesterday to build a large anaerobic digestion facility that will convert manure from elephants, giraffes and hundreds of other animals under its care into biogas. The plan is to burn the biogas to generate electricity — up to 5 megawatts — and use the waste heat from both the digester and the generation plant to heat zoo exhibits (offsetting more than $1 million of natural gas used by the zoo). This is just the latest biogas project to emerge in Toronto, which also plans to take methane from a large landfill, a major wastewater treatment plant, and two organic waste processing facilities to generate electricity, or alternatively, to fuel city transportation fleets. In all, biogas projects recently approved by the Ontario Power Authority under the province’s feed-in-tariff program, as well as projects in the pipeline, total well over 100 megawatts.

The Toronto Zoo, I should point out, isn’t just taking care of its own business. Only 2 per cent of its waste — a combo of animal manure, beddings and organic waste from on-site restaurants — will feed the digester. The rest will be a combination of organic waste from commercial and retail establishments in the surrounding community. Read the full story in the Toronto Star.

My Clean Break column this morning takes a look at a few ambitious initiatives in Toronto that will take biogas from the city’s main landfill and two anaerobic digesters, clean it up, and use it as transportation fuel, to heat city buildings, or to generate electricity. Actually, there’s a fourth major initiative — take biogas from the city’s largest wastewater treatment plant and use it for a combined heat and power plant. Together, these four projects have the potential to generate more than 40 megawatts of electricity, not to mention waste heat that can be redeployed to offset natural gas use. But all the gas won’t necessarily be used to generate power. Biogas from the two anaerobic digesters could end up being used to fuel the city’s entire fleet of 285 waste trucks, which would be converted from diesel to natural gas.

It’s good to see these initiatives finally taking shape… This is methane that would otherwise be flared, so it makes enormous sense to capture it and use it to offset our dependence on coal and conventional natural gas, or in the context of transportation, diesel fuel. Read the column for more specifics about the projects.

When we talk about using anaerobic digester technology to produce biogas from organic material, and then using that biogas to generate electricity, we’re usually talking about processing agricultural waste or manure out on some farm or rural facility. But what about the city? There’s thousands of tons of organic or “green bin” waste produced every day in cities like Toronto, and much of it still goes to landfill — particularly organics from multi-unit dwellings and industrial/commercial operations. (more…)