Wood takes edge off greenhouse costs
Wary of natural gas prices, some producers are installing wood-based heating systems.
When natural gas prices rise, Canadian farmers sit up and take notice. For those who depend on nitrogen fertilizer, of
which natural gas is a key component, there’s not much of a defence.
Greenhouse operators depend on natural gas both for heat and for the addition of carbon dioxide to the environment.
For these producers, at least, there’s an alterative: wood. Some producers in British Columbia, for example, are burning
wood made cheaper and more abundant by the urgent need to harvest timber damaged by the mountain pine beetle.
Near Kettleby, Ont., north of Toronto in the Holland Marsh region, the pine beetle isn’t an issue. An active market for
residential construction is. Since 1980, Foothill Greenhouses has depended - in full or in part – on leftover wood from
area construction sites to heat its seedless cucumber production. During that time, this family operation has grown from
three acres to 15 acres: 14 under doublepoly and one acre under glass.
Large capital cost
Ron Voorberg, whose father started the business in the 1950s, says heating with wood (he also uses natural gas
to introduce CO2) has been good for business. It’s allowed him to mitigate and reduce the uncertainty of the heating
cost increases his gas-burning peers have faced.
He sources ground-up wood from up to four suppliers and burns it to produce hot water, which is stored in large tanks. In concept, his current system is not unlike a home hot water heater. But he cautions that wood-based heating is no free lunch.
“The first thing is that there’s a big capital expense,” says Voorberg. “It’s around five times the capital cost of setting up a
gas-only heating system. You need to be prepared for a long payback period, too, of maybe five or six years.”
Major management input
Foothill has grown in several stages over the last 30 years. With conventional gas heating, expansion means adding another
gas line. Voorberg’s most recent expansion, in 2007, necessitated an overhaul of his wood-burning setup. He increased storage
capacity from 500,000 litres of hot water to 2 million litres. This is just one example of how wood burning takes on a life of
its own.
“We’re always saying that we do two things around here,” notes Voorberg. “We grow cucumbers and we burn wood. You need to be prepared to take delivery of wood when it’s available and store it until you need it, and that could be several thousand tons. And there’s a lot of mechanical work, too.”
Over the years, Voorberg has learned to take the extra management duties in stride. With natural gas prices as volatile
as ever, he appreciates the peace of mind that wood has allowed.
“We know our equipment costs and we know our wood costs,” he says, “and I like to have that cost-certainty.”
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