Farm biofuels: a green solution to the peaker and off-grid problems

The centrale de Bécancour gas-fired generation
plant remains operable despite the wave of fossil-
fuel plant closures in Québec (Image: Le Devoir)

When it comes to electricity generation, Québec is a model to be followed. Hydro-Québec's massive high-north projets have ensured that 97.2% of Québec's total energy production is sustainable hydroelectricity, while simultaneously having the lowest electricity prices in North America. Coal and oil power plants have been completely abolished across the province.

And yet, Hydro-Québec hasn't been able to crawl that final few percentile to total sustainability. For better or worse it is unable to rid itself of its few remaining gas and diesel power plants, which together provide 541MW of generation capacity in the province - which, though it comprises less than 2% of total electricity generation, is essential to the provincial electrical grid.

There are two functions these remaining plants serve. The first is to produce electricity in remote locations off the main electricity grid. Hydro-Québec runs 24 such plants, mostly located in remote far northern communities but also including the centrale des Îles-de-la-Madeleine diesel generation plant which supplies the entire electricity needs of the Magdelan Islands, a chain in the Gulf of St Lawrence famous for its pied-de-vent cheese and extensive white sand beaches.

The second is as what is known as a "peaker plant". Hydroelectricity is not a form of power generation which can be turned on and off rapidly, and when rapid changes in electricity demand occur causing "peaks" the grid requires large amounts generated within a very short time frame. The only reliable method we have of doing this is thermal power generation from fossil fuels. Québec's current peaker station is the centrale de Bécancour near Trois-rivières, a 4-unit gas turbine plant using natural gas. As described by Hydro-Québec itself,

"Given the relatively high cost of fuel needed to run these facilities, they are used only during periods of peak demand. These generating stations have the advantage of taking only minutes to start and stop operations, compared to the longer time frames required by other thermal power stations."

And right now, while Québec continues to burn fossil fuels fracked from shale and rinsed from tarsand in other provinces, there exists a renewable, carbon-neutral source of electricity the province could utilize without any capital investment that can be produced in Québec nearly immediately and in doing so help revitalize the rural economy: the biofuels - biogas and biodiesel.

Anaerobic digesters like this one in Stirling, ON
can utilize waste manure as well as wet biomass
like corn silage to produce biogas suitable for
electricity generation (Image: Biogas Association)

Here in Ontario the idea of producing agricultural biogas to fuel gas turbine power generation is nothing new. Currently 35 farms across the province have installed anaerobic digester / gas turbine systems which derive biogas from manure, vegetable crop stalks and excess silage. The system is surprisingly efficient: a single tonne of cattle manure can produce 48KWh of electricity, while a single tonne of corn chaff produces 335KWh.

In the case of manure, with a single head of cattle producing 21.9 tonnes of manure a year, the entire Bécancour plant could be fueled by capturing the gaseous output of only 391 cattle - or, put otherwise, the output of only 7 average québécois dairy farms. The equivalent in corn silage, with average wet biomass yields coming out to about 20 tonnes to the acre, would require only 62 acres.

Biofuels can also help to deal with the Magdelan Islands' diesel dependency. The madelinots have had to contend with oil spills recently from the shipment of diesel to the plant, when instead it could be using some of the $1.1 million worth of cereal crops produced in the region annually to produce their own diesel, creating jobs in this region with some of the highest unemployment levels in Québec.

Creating value-added production such as biogas is not only ecologically sound it is economically stimulating. The simple reality is that when processing of agricultural products is moved to the farm, jobs are created, and agricultural communities flourish. For Québec - and furthermore, the world - to make the final leap away from fossil fuels, it will take biofuels to be possible.