Greenhouse Canada

Features Energy Management
From the Editor: June 2011

March 16, 2012  By Dave Harrison

Getting energized on energy usage

One of the common threads running through many of our features of late has been energy efficiency. It’s a prominent theme in this issue. Natural gas prices have been stable for some time, giving growers a little breathing room as they struggle with currency pressures and other input prices. But fossil fuel prices can change at any time, and the trend over the past decade or so has been for them to rise.

So what can be done about it?


For starters, energy efficiency planning should be in every grower’s business plan regardless of the fuel used. There’s nothing wrong with fossil fuels. Years ago, one longtime grower explained to me that natural gas is so easy to use, and allows him to focus on the art of growing. There’s always a market for quality, he said. Alternative fuels require a whole new skill set he felt he didn’t have the time to develop and then utilize.

Whatever the fuel selection, growers should embrace all the energy conservation technologies and processes they can. The current generation of environmental controls software is a major assist, as are energy screens, which can save up to 30 per cent of energy costs. Considerable research on temperature integration strategies has been done at the Greenhouse and Processing Crops Research Centre in Harrow, Ontario, resulting in reduced energy usage per unit of produce in early fruit production. Work has been done on tomatoes, with new research planned on cucumbers and a pair of flower crops.

Embracing alternative fuels is another option. And we should include cogen systems in this discussion, since the process in greenhouse horticulture captures all the benefits of burning fossil fuels for cogen – electricity, heat and CO2. The lack of vision by Canadian politicians in not sufficiently encouraging such investment is galling to say the least, and reflects poorly on their energy management vision. Greenhouses can play a major role in electricity production without the need for new standalone public utility power plants.

One of the newest alternative energy projects involves a state-of-the-art anaerobic digestion facility in Leamington. Seacliff Energy Ltd. is fine-tuning its system that will utilize organic material to produce methane gas, which will then be used in an onsite cogen system to produce electricity for the provincial power grid. The heat will be used by the adjacent Pelee Hydroponics greenhouses.

It’s an environmental winner on all counts. It’s about as closed an energy loop as you can get. It diverts organic material that was previously landfilled, and captures methane that otherwise would have been released by that organic material. It produces baseline electricity for the grid, and the cogen’s heat is diverted into the greenhouse. And since no nutrients are lost in the process, the byproduct can be used as a fertilizer. We’ll see many more of these projects over the coming years.

Effective energy management continues to be a major challenge. (We haven’t even discussed transportation budgets.) Product margins can’t support a series of pricing spikes, and the
possibility of such spikes is on most growers’ minds. We’ve seen it before.

Embrace the new technologies, and review the new fuels. We can no longer grow the way we used to. ■

Print this page


Stories continue below