Greenhouse Canada

Features Alternative Fuels Energy

January 29, 2008  By Joel Ceausu

Conference speakers pointed to a variety of technologies available, or being developed, to deal with the energy crunch. The innovations can’t come soon enough for most growers. “A lot of us here use oil, and we are directly exposed to the rise in fuel prices,” said one delegate. “We feel it very severely.”

It is not news that energy costs related to greenhouse production constitute a significant part of total production costs for Québec greenhouse operators. Indeed, many feel rising fuel bills have become a threat to the survival of the industry in the province.

Energy bills vary on average from between 20 and 30 per cent of production costs. These figures themselves, however, depend on a variety of factors including the nature of crops grown, type of structure, level of insulation, time of year, and type of fuel, among other factors, according to Prof. Damien de Halleux of Laval University’s faculty of agriculture and food science.


“The choice of energy sources is a difficult, yet important, economic factor and requires important investments,” said Dr. de Halleux, adding that “once the investment is carried out, it is practically impossible to substitute one fuel source for another.”
Speaking last fall to a large audience at a growers’ conference sponsored by CRAAQ (Québec’s agricultural and agri-food reference centre), Dr. de Halleux said, “there is a clear upward (price) trend for the majority of energy sources. This was particularly the case with the majority of petroleum products over the last few weeks and months.” (The price of light fuel oil had gone from just below 50 cents per litre in the summer of 2004, to more than 75 cents per litre at the end of summer 2005, according to the provine’s Régie de l’énergie energy board.)

The price of fossil energy is related to trends in the price of crude and refining capacity. Given the many factors affecting the price (geopolitics, supply and demand, speculation), said Dr. de Halleux, it’s almost impossible to speculate on long-term trends.

“Nor should we as producers engage in energy speculation. That’s not what we do best,” insisted Stéphanie Colombe, a small cucumber and tomato grower in the Montérégie region. “A lot of us here use oil, and we are directly exposed to the rise in fuel prices. We feel it very severely.”

Electricity is mainly used for supplementary lighting, said de Halleux, “but thanks to the release of heat from lamps, lighting constitutes a considerable source of heat for operators.” However, it’s important to note that recent and foreseeable increases in electricity rates, and particularly the planned termination of the province’s dual energy tariff for growers, will affect them significantly.

Colombe agreed, and singled out Hydro-Québec for some criticism. “The utility owned by the people of this province is not serving its agricultural interests very well. If we have to worry about the price of oil from foreign countries to grow tomatoes in our backyard while we own all this electricity, then something is very wrong.” Even if electricity increases are less dramatic than those for fossil fuels, “they are nonetheless real increases.”

After a number of increases over the last few years, Hydro-Québec has presented yet another request to raise prices next fall. Moreover, the dual energy tariff intended to assist greenhouse growers is about to disappear. While several compensatory measures are planned for electricity for lighting purposes, they are accompanied by considerable increases (five per cent per annum over three years). 

Renewable energies, including wood and biogas, are increasingly popular.

The use of wood or wood byproducts has allowed many growers to shield themselves somewhat against rising costs. However, these are still resources in demand for a variety of uses and whose prices are also on the rise. 

Biogas, derived from food or farming waste, manure, or the degradation of organic matter in landfills, is also attracting attention. The use of manure could prove to be an interesting alternative in the medium and long-term, but it would require industrial support on a Québec-wide scale, said Dr. de Halleux. Because of the large investment, “biogas recovery from landfills is probably economically viable only for large operations (three hectares and larger).”

Some interesting new technologies include closed greenhouse systems, wind power and retractable foam, all of them garnering attention in Québec, though their uses have hardly been explored.

“It’s at least a good sign that we are interested,” said Henriette Latraverse, who produces hanging baskets and poinsettias in Laval, just north of Montreal. 

Electricity from wind power is attracting considerable interest. Several large-scale private sector wind park ventures are in the works and contracts to purchase the energy are currently being negotiated with Hydro-Québec.

There are many small-scale, on-farm projects in Europe. However, without significant government assistance, it might be difficult to make wind turbines profitable on such a scale in Québec because electricity prices here are still two to three times less than those in Europe.

The closed greenhouse concept features no venting; surplus summer heat is stored underground by a heat exchange system to be recovered in winter. Preliminary results are showing higher yields of up to 20 per cent. Part of this increase is explained by maintaining an optimal, CO2 enriched growing environment for much longer periods of time. While energy savings were considerable, said Dr. de Halleux – about 37 per cent – the concept is not easily adapted to Québec because of a climate that is much different than that of the Netherlands where such tests are being carried out.

The foam concept developed by Sunarc of Montreal consists of injecting and distributing retractable liquid foam between two poly films. This continuously recycled foam is injected at the beginning of night during cold periods and acts as an insulator.

Foam is then recovered in liquid form at the end of the night to let solar radiation in during the day. During warmer seasons, the same system acts as a shade. The foam produced significant energy savings and higher yields in tests in Québec, said Dr. de Halleux. 

Whichever methods growers use to reduce their production costs, he said, and there are many available technologies, the current situation for growers is not easy considering the significant rise in energy prices.

“Producers must therefore pay detailed attention to every possibility to reduce heating costs … and we must be vigilant with respect to what is tested and developed elsewhere in the world, while knowing that a functional technology elsewhere is not necessarily good in Québec, and will probably have to be adapted to our context.”

Joel Ceausu is a freelance writer and photographer in Québec.

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