Energy & Power
Atikokan Generating Station now 100% biomass
By Anthony Capkun
September 10, 2014 – Ontario Power Generation’s (OPG) Atikokan Generating Station (GS) is now operating on biomass, adding the station is the largest power plant in North America fuelled by 100% biomass.
“Close to 100% of the electricity OPG produces is from sources that are virtually free of emissions that cause smog or contribute to climate change,” noted OPG president and CEO Tom Mitchell. “Atikokan GS is a unique addition to our clean energy portfolio as it provides dispatchable, renewable energy that can be used when the power system needs it.”
“The biomass conversion and solutions developed for the Atikokan GS are cutting-edge, and OPG is at the forefront of this innovative technology,” Mitchell added.
According to The Pembina Institute’s Biomass Sustainability Analysis (2011), a biomass program using wood pellets at a rate of 2 million tonnes/year is possible with no systemic decline in forest carbon stocks over time. Together with Ontario’s sustainable forest management planning process and practices, this means OPG’s biomass program can satisfy the United Nations Framework Convention on Climate Change (UNFCCC) definition of renewable biomass. Fuel at Atikokan GS is required to come from sources meeting the UNFCCC definition of renewable biomass.
OPG has fuel supply contracts in place with two companies in northwestern Ontario—Rentech Inc. and Resolute Forest Products Canada. Each will supply 45,000 tonnes of wood pellets annually. Both suppliers have employment arrangements with local Aboriginal communities. Transportation contracts are also in place.
Pellets are received from self-unloading, rear discharge trucks that have their own discharging system built into the trailers. A new receiving system transports the pellets to the large storage silos by conveyor belt and a bucket elevator. When needed for production, the pellets are delivered to the plant on a first-in, first-out basis from the silos via new conveyor belts and a second bucket elevator.
Once inside the powerhouse, the pellets are pulverized and fed into the boiler, much the same way as coal previously. Due to the similar heat content of lignite coal and wood pellets, the Atikokan boiler design was an ideal candidate for fuel conversion, says OPG. All 15 burners were replaced with Doosan Mark IV biomass burners. New ash transport systems have also been installed.
Atikokan GS and Thunder Bay GS burned their last coal for electricity production on September 11, 2012, and April 8, 2014, respectively. The coal plants at Lambton GS and Nanticoke GS are being placed in a safe shutdown state and will remain in place with the potential to be converted to clean fuel in the future. All OPG thermal plants have now ceased burning coal.