Manure Manager

A hungry locavore has been living behind Vandermeer Greenhouses in Niagara-on-the-Lake since April of 2009, feeding mainly on a diet of grape pomace as well as some corn, “off-spec” dry dog food, fermented grass, and peppers in season.

And it’s taken the 100-Mile diet that’s become a creed with carbon-footstep-conscious foodies a giant step further by shrinking its foraging area to a much more impressive 15-mile radius.

It’s a high-yield anaerobic digester that converts food waste into methane gas that fuels a natural gas engine that powers an electrical generator. Taken altogether, that means saving money on energy costs, says Randy Van Berkel, general manager and hands-on grower at Ontario’s largest chrysanthemum greenhouse. It’s one of the two largest in Canada, growing 20 varieties of spray chrysanthemums – 5-1/2 million stems a year – that are shipped to Canadian wholesalers as far away as Québec City.

, a word that entered our vocabulary just a few years ago, is by definition anyone who eats exclusively, or at least primarily, what’s grown locally – the closer the better – in order to create a connection between themselves and their food sources. By doing so, they support the local economy and reduce their carbon footprint.

That pretty much sums up the eating habits of the Vandermeer Greenhouses digester that makes a further contribution to the ecological cause. Heat from the engine is used to warm the greenhouse in winter when chrysanthemums are growing, while the electricity that’s generated powers some 2,200 high-pressure sodium grow lights. As well, the organic fertilizer end product can be used in the greenhouse.


Randy Van Berkel is its principal dietician. Along with his right-hand-man Kyle Bartel, they make sure there’s enough food on hand to keep the digester running at peak capacity.


“It’s barely affordable, but worth it,” Randy said when asked about the capital cost of the system. He says there’s a five-to-seven-year payback, depending on the cost of hydro and it should cut his electrical bill by $160,000 a year. Since he’s just 29 years old, he should see it pay for itself many times over.

Some of the start-up cost was offset by government grants that are available for alternative energy projects from solar, wind and anaerobic digesters while operating costs are subsidized by feeding surplus power into the local electrical grid through RESOP (Renewable Energy Standard Offer Program).

A wind turbine was Randy’s first choice for alternative power, but that idea was put on hold by the municipality, which wasn’t prepared to deal with large turbines that generate electricity when it was already fielding complaints about noisy farm wind machines. The wind machines are used sparingly by grape growers to move cold air to prevent winterkill of vines and spring frost damage to buds.

Then he saw the anaerobic digester that Bayview Flowers in nearby Jordan had installed a few years ago, and took a field trip to Germany where some 4,000 are in operation.

“I said ‘wow,’ could this work here?”

Sold on the technology, he had one built by PlanET (pronounced plan-e-t, ET for Energy Technology) Biogas Solutions (PBS) in St. Catharines. It’s the same company that built the digester at Bayview Flowers and is allied with PlanET Joint Venture based in Vreden, Germany, near the border with Holland. That digester is fuelled primarily with non-commercial grade dry dog food. The company has built two other digesters on cattle farms in Ontario and has proposed a third greenhouse unit for a grower in Grimsby.

The digester/generator at Vandermeer Greenhouses produces 335 kW of electricity, which is enough to power 250 homes. Over the winter grow period from November to April, it helps offset the peak electrical 890 kW demand of the greenhouse.

“Right now I need 90 kW,” Randy said on a warm day last summer. The rest is fed to a roadside transformer and into the local power grid and is sold to the local utility.


Vandermeer Greenhouses was one of five Niagara region farm operations – and 55 in Ontario – to earn a Premier’s Award for Agri-Food Innovation Excellence in 2009 and the $5,000 that goes with it. The company was recognized for being the first in the province to use grape pomace as a main fuel for the on-farm anaerobic digester. Currently, much of the pomace from wineries is put into landfill and some is returned to the soil as a nutrient, although it tends to be acid-rich and has to be neutralized.

Randy estimates he uses 5,000 tonnes of pomace a year from a number of neighbouring wineries. The largest sources of pomace are the two Vincor Canada estate wineries (Inniskillin and Jackson-Triggs), and Vincor’s large Niagara Cellars winery in nearby Niagara Falls.

It’s estimated that 20-30 per cent of each tonne of wine grapes is pomace – the grape skins and seeds – so what Randy uses would be about a third of all the pomace from last year’s 60,000-tonne Ontario grape crop.

Peppers – in this case, red peppers – are another food source for the digester. “There’s not much energy in peppers, but there’s a steady, large supply,” Randy said about sourcing them locally.

“It has to stay close or otherwise forget about it, it doesn’t make enough gas for us to haul from any distance,” Randy said about his choice of grape pomace as a primary food source for his digester. “I charge (wineries) only what it costs me to pick it up,” he says about a business plan to build a good relationship with wineries and put himself in a position where no one can compete with him on price.

The pomace is stored in four bunkers and covered with a heavy plastic tarp that’s weighed down by used tires. Leachate is collected in a separate pit below the bunker. Controlling the smell of any fermentation in the bunker was Randy’s first concern. He said he walked the perimeter of the seven-acre property and could only catch faint sweet smelling whiffs of the pomace if the wind was right.

Since the digester operates oxygen-free, there’s no smell. That’s a good thing, as the process is triggered by filling the primary digester tank with liquid cow manure, heating it to 38°C degrees and waiting 30-40 days.


“It’s like a cow’s stomach,” says PBS president Clare Riepma. “Enzymes break down food and the microbes multiply producing biogas that’s largely methane.”

He said microbes like a consistent environment (38°C degrees in this case) and they don’t like a change in their diet. “Keep everything the same and they’ll produce biogas like there’s no tomorrow. It’s a natural process and we optimize it to run automatically.”

The pomace is fed into a hopper and a small amount each hour is fed automatically into the digester. Material moves into a second digester where more gas is produced and trapped under a membrane roof in each digester. Randy monitors the process to make sure it’s operating at peak efficiency.

Vandermeer Greenhouses has long been regarded as an industry innovator. It was last featured in our March 2003 edition following a major expansion and modernization program, and before that, in September 1987 for its supplementary lighting trials with cut mums.

Jim Meyers is a freelance writer and photographer in the Niagara region of Ontario.


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