Case Studies
Featured Case Study
Walker’s integrated gas recovery system upgrade saves the City of Ottawa from a $2-million investment
|City of Ottawa
Walker’s upgrade to the Trail Road Landfill gas collection system saves the City of Ottawa from unnecessary expenditures while reaching environmental goals.
The Trail Road Landfill Gas to Energy Facility, owned through an Ontario-based partnership between Walker, Comcor Environmental and Energy Ottawa Inc., is located at the City of Ottawa’s Trail Road Landfill site that enabled the city to tap into revenues from its existing source of landfill gas while saving on capital costs.
The existing landfill gas collection system at the Trail Road Landfill had routine operating and maintenance costs of $200,000 per year and was anticipating a capital investment of $2 million in upgrades and repairs to keep the system collecting optimal levels of gas. However, by implementing an upgraded landfill gas collection system that added new wells and related collection piping, Walker and its partners helped the city save on these expenditures while also achieving significant environmental benefits.
By collecting and using the landfill gas for renewable energy generation rather than flaring the surplus capacity, the site managed to reduce its greenhouse gas emissions by up to 180,000 tonnes (relative to 1990 levels). In doing so, the facility could generate up to 5 MW of renewable energy and divert the production of 40,000 tonnes of carbon dioxide from fossil fuel derived electricity.
Savings of $200,000 per year
in operating and maintenance costs
5 MW of renewable energy
generated from landfill gas
Reduction of 180,000 tonnes
in greenhouse gas emissions
Project Benefits
- $2 million capital cost savings
- Annual savings of $200,000 in operating and maintenance costs
- Royalty payments to the City of Ottawa estimated at $150,000 per year for the use of the gas by the generating plant
- Enough power to serve 5,000 Ottawa homes
About the Facility
Until 2007 the Trail Road Landfill collected landfill gas, which is made up primarily of methane (50%) and carbon dioxide (50%), from the existing landfill gas collection system and combusted it in a Ministry of the Environment approved enclosed flare. The flare is now used as a standby unit.
The Trail Road Landfill Gas to Energy Facility takes landfill gas that has been flared and directs it to five (5) Jenbacher JGC320 internal combustion reciprocating engines.
- Each engine is direct coupled to a 480-volt synchronous 1 MW generator.
- The electrical generation is stepped up to 27.6 kV for export to the local distribution system owned by Hydro Ottawa.
- Each engine consumes approximately 600 standard cubic metres per hour (350 standard cubic feet per minute) of landfill gas.
- Other than for routine maintenance, the gensets (engines) will operate 24 hours per day, 365 days per year and the flare will become a standby landfill gas control combustion device.
- Each engine/generator is packaged in a standard ISO steel container which houses the engine, generator, lubrication, cooling, controls, switchgear, and exhaust systems.
- The engines are each equipped with an exhaust gas silencer to minimize noise emissions.
