Can North America’s largest coal plant convert to biomass?
My Clean Break column today takes a closer look at efforts by Ontario Power Generation to convert some of its coal-fired generating assets into biomass-burning power plants, including potentially several units at its Nanticoke Generating Station — North America’s largest coal plant. The provincial Liberal government has vowed to shut down the last of Ontario’s coal plants by 2014, and biomass conversion is being seriously considered as a way of partially getting there. It’s an ambitious undertaking, given the scale of such a project, but successfully making it happen would solve many problems with one solution.
Shutting down Nanticoke, while a good move for environmental reasons, will cause many headaches in the area. More jobs will be lost in a region of the province already suffering from economic decline. Mothballing Nanticoke leaves a 4,000 megawatt hole in Ontario’s grid. And the loss of that generation takes away some crucial voltage support for the entire electricity system. By converting three or four of the eight units at Nanticoke into biomass and shutting down the rest, some jobs can be kept, some voltage support and generation is kept, fewer new plants or transmission projects are needed in the area, and the large demand for biomass can create a local supply chain that could provide a significant boost to the regional economy.
OPG has tested biomass burns and blends at all four of its plants — Nanticoke, Thunder Bay, Atikokan and Lambton — but so far the most progress has been at Atikokan, a 200-megawatt plant that in July successfully burned 100 per cent wood pellets for a day. A three-day burn is scheduled for early December, and OPG officials say Atikokan will likely be the first plant converted to biomass. After that, attention will likely turn to Nanticoke, which has so far co-fired wood pellets and wheat shorts with coal as part of tests.
Blending isn’t the final objective. Blending produces ash that can’t be used by the cement industry, like coal ash, and can’t be used as fertilizer, like pure biomass ash. But getting to 100 per cent biomass burn has some technical issues, including the impact on equipment (i.e. soot buildup and the extra maintenance required to clean it) and the difficulty of establishing a secure supply chain. The latter issue is what OPG considers its biggest challenge, given the huge volumes of locally produced, non-food biomass it would require.
Despite these challenges, it’s encouraging to see the province moving in this direction. I don’t think converting coal plants to biomass is a long-term solution, but it’s a good medium-term solution that will create a stable local supply chain. As the remaining Nanticoke units are retired, the biomass can go toward supporting the emergence of more efficient combined heat and power (CHP) plants distributed throughout the area.