Plant powered up by wastewater
The Regional District of Nanaimo is putting its excess gas to good use.
The completion of a brand new cogeneration system at the Greater Nanaimo Pollution Control Centre will allow the wastewater treatment facility to not only produce self-sustaining heat, but also enough electricity to power 325 households per year.
Sean DePol, RDN manager of wastewater services, said the treatment plant will be the first of its size in Canada to implement cogeneration.
“We are at the leading edge,” he said. “We are going to get those answers of what it’s going to cost to operate and maintain so other facilities that want to do a similar thing will have concrete numbers that they can put into a business plan to move forward.”
Cogeneration facilities are defined by the ability to provide two sources of energy. In the RDN’s case, they will use the excess biogas created when wastewater sludge is stabilized and reduced in volume by the treatment plant’s anaerobic digesters, to heat the plant and generate electricity.
Historically, that biogas was used as a heat source, however only 40 per cent of the gas was utilized, DePol said.
He added that while there will be maintenance costs to determine in the next year of operations, being a sustainable energy producer will provide environmental and cost savings in the long run.
“The amount that we receive per kilowatt that we will sell to B.C. Hydro is almost double what we purchase off B.C. Hydro,” he said. “We will be making a profit on this, we just don’t know what it will be.”
“In addition to that, as we expand the treatment plant to secondary, we’ll be removing more organics out of the wastewater, which means we’ll have more organics to go into the digesters, which means we’ll produce more biogas and an even greater quantity of heat and electricity.”