Hamilton Renewable Power Incorporated: 2008 Winner of the Canadian Council of Ministers of the Environment Pollution Prevention Award for overall reductions of greenhouse gases
Hamilton Renewable Power Incorporated was established to carry out the construction, operation and maintenance of the City of Hamilton’s biogas cogeneration facility. Overseeing the operation of the facility is a Board of Directors consisting of the city mayor, councillors and staff representing various departments across the city.
Description
In 2005, the City of Hamilton initiated a biogas cogeneration project at the Woodward Avenue Wastewater Treatment Plant. Hamilton was the first municipality in Ontario to receive approval from the Ontario Electricity Financial Corporation (OEFC) to build a generator for sustainable green energy. The OEFC’s approval was one of the major reasons the project was able to proceed.
Completed in the fall of 2006, the cogeneration facility produces clean and renewable energy that significantly reduces its reliance on external energy sources. The project also allows the City to lower its energy consumption, increase its energy efficiency, reduce greenhouse gases and minimize the amount of natural gas required to heat the wastewater treatment plant and wastewater digesters. The project was undertaken to generate revenue, cost savings and environmental benefits.
At the wastewater treatment plant, a biological process treats wastewater and produces a sludge material. The sludge is then anaerobically digested in wastewater digesters to reduce the volume of the material and to allow for ease of disposal. During the digestion process, the solid material in the sludge is converted into biogas. This biogas is generally 65% methane and 35% carbon dioxide. Previously, the biogas had been directed to two gas flares that combusted the gas and prevented the emission of these greenhouse gases into the atmosphere. However, the energy content of the biogas (which accounts for approximately 60 to 70% of the energy content of piped natural gas) was completely lost during this step.
With the cogeneration facility, the biogas that had been previously wasted as flare gas is instead sent through a reciprocating biogas engine that converts the methane stream to electricity. Additionally, the heat that is generated by the engine is recovered using a series of heat recovery systems that redistribute the heat back to the wastewater treatment plant for space heating and warming the digesters.
Woodward Avenue Wastewater Treatment Plant facts:
- It is the largest of three wastewater treatment plants that the City of Hamilton manages.
- It services a population of 380 000.
- It has the capacity to handle 409 000 cubic metres per day of wastewater.
- Anaerobic digesters produce approximately 17 000 cubic metres per day of biogas.
Benefits
Environmental
This facility produced approximately 16.4 million kilowatt-hours of clean renewable electricity in a little over a year. The electricity produced by the cogeneration facility replaces electricity drawn from the grid; over 80% of electricity drawn from the grid is produced by technologies such as coal-fired power plants that produce greenhouse gas emissions. The conversion of methane into energy eliminates the emission of approximately 60 000 tonnes of greenhouse gases to the atmosphere on a yearly basis.
The heat that is recovered from the combustion engine offsets the natural gas requirements to power the wastewater treatment plant. In this same time frame, the facility recovered approximately 15.7 million kilowatt-hours of thermal energy, resulting in a reduction of natural gas consumption by 1.5 million cubic metres. The total energy requirements of the facility have declined by 15%.
Economic
The City signed a 20-year contract with the Ontario Power Authority to sell electricity (contract expires in 2026). On an annual basis, the City receives approximately $1 million in revenue from electricity sales. Previously, the biogas generated at the Woodward Avenue Wastewater Treatment Plant was simply flared off, offering no revenue stream. The thermal energy recovered from the engine saves the City approximately $450,000 in natural gas costs.
Social
Producing electricity locally allows Hamilton to be a more self-sustaining community and less reliant on the electricity grid.
Recognition
2008 – Canadian Council of Ministers of the Environment Pollution Prevention Awards – Greenhouse Gases Reduction Award
Contact Information
Jim Harnum
Senior Director - Water and Wastewater Division
55 John Street, North
Hamilton, Ontario
L8R 3M8
Phone : (905) 546-2424 ext. 4483
Fax : (905) 546-4491
E-mail : Jim.Harnum@hamilton.ca
Date Submited
August 2008
Note: The purpose of this sheet is to give recognition to this specific activity in pollution prevention. Environment Canada does not per se endorse the company.