Landfill Gas Collection & Power Generation System
The City of Saskatoon has a long rich history of generating electricity. The municipal electric utility was started in 1906, with a small generating plant of 225 kilowatts located on the riverbank at Avenue H and 11th Street. By 1911, the City started its second plant on Avenue A south of 19th Street. In 1928, the City sold its power assets to the Saskatchewan Power Commission, ending electricity generation by the City, until 2014 when the City opened the Landfill Gas Collection & Power Generation System. The Landfill Gas Power Generation Facility is the first power generation facility to be built by the City in over 100 years. Saskatoon Light & Power is committed to returning to our generation roots, developing and implementing new ways of generating power that provide benefits to our customers, the environment, and the City.
Landfill Gas Collection & Power Generation System
The Landfill Gas Collection & Power Generation System began operation in 2014, and is operated by the City of Saskatoon. The key benefits provided to the City include:
- Reducing Greenhouse Gas (GHG) emissions by over 50,000 tonnes per year - equivalent to removing over 10,000 vehicles from our roads each year.
- Producing enough energy to power 1,200 homes each year.
- Improving the air quality and reducing odours at the Landfill.
- Creating approximately $1.3 million in annual revenue for the City from the sale of power generated by the project to SaskPower.
Details on the Landfill Gas Collection & Power Generation System
The system consists of two facilities that work in conjunction to produce electricity from the City's Landfill Gas: the Collection Facility and the Power Generation Facility. The Collection Facility is made up of vertical wells drilled into the waste in the landfill, and underground piping connected to a vacuum compressor to collect the gas that is produced. The landfill gas is then piped to the Power Generation Facility where the gas is combusted in engine-generators sets to generate electricity.
This illustration shows where the facilities are located at the Landfill.
How Landfill Gas Becomes Green Energy
About five million tonnes of municipal waste are now in place at the Saskatoon Landfill. As organic waste decomposes, it produces landfill gas that contains almost equal parts methane and carbon dioxide. If this gas is not collected, it is emitted into the atmosphere and adds to the overall greenhouse gas emissions in our community. Methane gas is about 25 times more harmful to the atmosphere than carbon dioxide.
The collection process involves covering or "capping" a section of the landfill with clay, drilling vertical wells into the waste and connecting them with underground piping. Vacuum compressors then capture the gas and pipe it to a blower/flare station, where it is either piped to the power generation facility or combusted in a flare. During the combustion process the methane is converted to carbon dioxide, a less harmful gas. While effective at reducing methane gas emissions, ending the process at this point makes no use of the heat energy that is produced during the conversion. After the gas is collected, it is piped to a power generation facility and combusted in two engine-generator sets to generate electricity.
The cost of the project was $15 million. It was partially funded ($6.75 million) by the Government of Canada through the Canada-Saskatchewan Provincial-Territorial Base Fund. The remainder was funded from internal City reserves.
The revenue generated from the sale of the energy to SaskPower will be used to pay for the project. After nine years, all profits will go back to the City for use in developing additional green power generation projects.
Building the Landfill Gas Collection & Power Generation Systems
Frequently Asked Questions
Is landfill gas harmful to the environment?
As landfill waste decomposes, a type of gas, called 'landfill gas' (LFG), is produced and emitted into the atmosphere. Landfill gas contains almost equal parts of methane and carbon dioxide. Methane is about 25 times more harmful to the environment than carbon dioxide. The larger the landfill is, the more gas is produced. While emissions decline year after year after a landfill is no longer in use, they continue to emit gas into the atmosphere for as long as 100 years.
Is landfill gas harmful to our health?
LFG is lighter than air and rises up into the atmosphere. LFG contains methane, and may contain trace amounts of hydrogen sulfide and volatile organic compounds (VOCs). It does not generally present a risk to public safety, unless the gas is present in high concentrations or in a confined space. Safeguards such as gas monitors and ventilation systems are in place to minimize these hazards and protect workers at the facilities.
How will the Landfill Gas Collection System benefit the environment?
The facility reduces annual greenhouse gas emissions by over 45,000 tonnes per year. That's equivalent to removing over 9,000 vehicles from our roadways each year.
Does the project offer any other benefits to City residents?
Yes, the air quality at the Landfill will be improved and odours in the area will be reduced.
How much power is produced through this process and what does the City do with it?
The total electricity generated is enough to power about 1,300 homes each year. This electricity is sold to SaskPower for about $1.3 million each year. Using this revenue, the project will pay for itself in about nine years. After that, all profits will go back to the City to fund additional green energy projects.
Why is the City selling the power instead of using it?
The Landfill Gas Collection System was one of 20 projects selected in the SaskPower Green Options Partners Program Lottery in June 2011. The program allows power producers with generator capacities between 100 kilowatts and 10 megawatts to generate and sell environmentally preferred (e.g., biogas, heat recovery, low-impact hydro, solar, and wind, etc.) electricity to SaskPower.
A 20-year economic analysis indicates it is more advantageous to sell the electricity from the Landfill Gas Collection System to SaskPower, than to interconnect with Saskatoon Light & Power's distribution system.
How does the Collection System work?
A clay cover, or 'cap' was installed over a section of the landfill. Once the cap was in place, vertical gas wells were drilled into the waste, and interconnected with underground piping. A vacuum compressor collects the gas and pipes it to a blower/flare station, where it is either piped to the power generation facility or combusted in a flare. During this process, the methane is converted to carbon dioxide, a less harmful greenhouse gas.
Are there any health or safety concerns associated with the project?
Local air quality at the Landfill has improved as a result of the project by capturing and thermally destructing the methane that were already occurring from the Landfill.
Exhaust is emitted from the facility when in use, however these emissions must comply with the Clean Air Act in the Province of Saskatchewan, which regulates emissions from fuel burning equipment. Air dispersion modeling has been completed as part of the Environmental Screening for the project.
Also, similar to any industrial facility that processes or uses a combustible gas, the power generation facility was designed to include combustible gas detection instruments that shut down equipment if elevated concentrations of combustible gas are detected. All equipment in the vacuum compressor building was also designed to meet Canadian Electrical Code requirements.
How large are the project components?
The Power Generation Facility is enclosed with fencing and is located near the SaskEnergy regulating station west of the landfill, and is home to the electrical substation equipment and a 3,400 square foot industrial building.
The Gas Collection Facility is a fenced area and includes a 2,400 square foot building located at the entrance to the Landfill. The gas flare stands 40 feet high.
What was the cost of the project and how is it being funded?
The capital cost of the project was $15 million. It was being partially funded ($6.75 million) by the Government of Canada through the Canada-Saskatchewan Provincial-Territorial Base Fund. The remainder was funded from internal City reserves.