Atikokan generating station operating on biomass
Ontario
Power Generation’s (OPG) Atikokan Generating Station (GS) is now
operating on biomass, making it the largest electrical power plant in
North America fuelled by 100% biomass.
“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,” said OPG’s president and CEO, Tom Mitchell.
“The biomass conversion and solutions developed for the Atikokan GS
are cutting edge and OPG is at the forefront of this innovative
technology. The project is the first of its kind in Ontario and will
bring economic benefits to northwestern Ontario for years to come,” he
added.
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 for a
total of 90,000 tonnes. Having two suppliers enhances reliability of
supply. Both suppliers have employment arrangements with local
Aboriginal communities. Transportation contracts are also in place.
The Atikokan GS is a former coal-fired electrical facility. The
conversion project got underway in mid-2012 with ground preparation and
the construction of two silos, each 44 metres tall and 21 metres in
diameter. Each silo can store up to 5,000 tonnes of wood pellets.
Modifications to the boiler and a new distributed controls system were
also required. As well, new truck receiving and transfer infrastructure
was built.
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 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 was previously. Due to the similar heat content of
lignite coal and wood pellets, the Atikokan boiler design was an ideal
candidate for fuel conversion. All 15 burners were replaced with Doosan
Mark IV biomass burners. New ash transport systems have also been
installed.
The Pembina Institute conducted a Biomass Sustainability Analysis in
2011 that included climate change implications of electricity generation
using biomass fuel. The report identified that harvesting biomass for
electricity production is sustainable. A biomass program using wood
pellets at a rate of two million tonnes per year is possible with no
systemic decline in forest carbon stocks over time. This, together with
Ontario’s sustainable forest management planning process and practices,
means OPG’s biomass program can satisfy the United Nations Framework
Convention on Climate Change (UNFCCC) definition of renewable biomass.
All OPG thermal generating stations have now ceased burning coal.
Read More: Biomass Steam Boilers