André Mousseau is from the old school, but he likes to think about the future.
In his greenhouse in Sainte-Marie-Madeleine, in Montérégie, he patiently turns a crank to move huge tables covered in cactus. A passage then opens between the rows of succulents allowing access, at the other end of the glazed room, to his favorite toy: a brand new heat pump.
The device, contained in a large metal box, is connected to metal pipes which draw air from the greenhouse. It is also connected to water pipes that wind under the concrete floor. This electrical system, which allows it to greatly reduce its GHG emissions compared to what heating with fossil fuels would produce, is a rarity in the Quebec greenhouse environment.
Among the approximately 1,000 greenhouse producers in the province, there are only about ten who heat with electricity, says Mr. Mousseau, who is also the president of the Producers in greenhouse of Quebec. Many large companies use biomass, biogas or waste heat from industrial neighbors, but the vast majority of small greenhouse producers heat with propane, fuel oil or natural gas.
“I have always said that we must be able to heat our greenhouses with electricity. Unfortunately, for small producers, the easy solution is still propane right now,” laments Mr. Mousseau, a burly fellow with a long white beard, while his employees right next door are busy potting cacti.
This state of affairs continues despite the Quebec strategy launched in 2020 aimed at doubling greenhouse production in five years. This initiative, which is accompanied by preferential electricity rates and financial assistance for the development of greenhouses, has not yet led to a massive switch to electricity among small producers, according to people in the community consulted by The duty.
For its part, the Ministry of Agriculture, Fisheries and Food of Quebec (MAPAQ) was not able to detail how many of the 108 projects accepted under the Greenhouse Business Support Program (2020-2024 ) will rely on electricity — Quebec’s energy resource par excellence — for their heating.
Mr. Mousseau’s first heat pump, installed in 2020, is the subject of an experimental project aimed at better understanding how to use the “thermal battery” hidden 20 cm under the floor. It is a network of pipes through which water circulates. When, during the day, the sun heats the air in the greenhouse to too high a temperature, the heat pump extracts this heat and stores it in the floor. At night, the operation of the device is reversed, which heats the greenhouse using the heat from the floor.
A second heat pump, installed in 2021, is located outside the greenhouse. It heats installations in a more traditional way, extracting heat from the outside air. With every joule of electricity, it can inject three joules of heat into the greenhouse — considerably more efficient than conventional electric heaters.
These systems are expensive: even with the various subsidies, Mr. Mousseau will have to pay the bill for five years. However, after that, he hopes to save $10,000 in heating costs per year. Its electrical system met 30% of needs in the last year; natural gas did the rest. With its current equipment, the veteran producer thinks it can increase the share of electricity to 40%.
According to a report by the Institute for Research and Development in Agro-Environment published in 2017, greenhouses in Quebec emit nearly 70,000 tonnes of CO equivalent.2per year for their heating, the equivalent of 25,000 cars. The carbon footprint of a tomato grown in a greenhouse heated with fossil fuels can also exceed that of the same fruit imported by truck from Mexico.
Interesting, but…
Among small greenhouse producers, “the interest is there” for electric heating, observes Philippe Provencher, an engineer from the firm Gobeil Dion & Associés, of Saint-Lambert, specializing in greenhouse heating. “Hydro-Québec’s rates ensure that they have access to energy that is competitive with propane or fuel oil,” he explains. And there is also the ecological aspect which is really important for them. »
In the future, there will be more and more examples of completed projects. We will see the development of a way of doing things that will work well and that will not be too expensive.
Despite this, Mr. Provencher admits that his firm supports very few customers in a successful conversion to electric. Even if there are savings at the end of the course, the producers must have the “solid back” for the initial investments, he underlines. And small greenhouse growers who don’t grow all year round need more time to repay their loans.
Frédéric Jobin-Lawler, co-owner of Abri Végétal, which grows organic vegetables in a greenhouse in Compton, in the Eastern Townships, is one of the few producers who are in the process of switching to electricity.
His conversion project takes time to materialize, in particular because his farm was not connected to the three-phase electricity network, necessary to obtain great power. “Our goal is to heat with electricity next winter,” said Mr. Jobin-Lawler over the phone. We were told that we should be connected to the three-phase network in October 2022, although we made the request more than a year ago. »
The producer also encountered difficulties in finding a contractor available and capable of installing its new heating system, which should meet 80% of its needs.
In addition to the technical expertise that is lacking, security of supply is another major obstacle to the adoption of electric heating, deplores Mr. Mousseau. “Me, there, here, if I don’t heat for half an hour, in the middle of winter, everything dies,” he says in the middle of the cacti. Even if greenhouse producers always have spare systems, Hydro-Québec must reassure them and guarantee them power at a good price and in the long term, according to him.
Even if the shift of small greenhouse growers to electric takes time to materialize, engineer Philippe Provencher believes that Quebec is on the right path. “It won’t be a boom, it will happen gradually. It’s easier to install electricity in new installations. In the future, there will be more and more examples of completed projects. We will see the development of a way of doing things that will work well and that will not be too expensive. »
For greenhouse producers, adopting electric heat pumps could have an unsuspected advantage: they not only heat the greenhouse in winter, but also cool it in summer when nights are too hot. This risk of overheating, which especially threatens producers of tomatoes and peppers, should also increase in the coming decades with the warming of the climate.