Digging deep
Geothermal vs geoexchange – which could work and where in Canada | 14
Cultivating a living soil How regenerative and organic fit into greenhouse culture | 24
The strawberry switch Greenhouse producer swaps out tomatoes for strawberries, staying carbon-negative | 36
JUNE 2022
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Using insights from the last poinsettia season to tackle the next | 28
BY J. LYNN FRASER
Geo-which? Deep geothermal vs geoexchange; how to decide whether they work for you.
BY GRETA CHIU
Deciphering the price of carbon A snapshot of carbon taxation across the nation
BY JAMES WILLIAMS
There’s a big focus on energy in this issue, and I have to say, it’s rather timely.
Seeing the situation in Europe as well as continuous increases in gas pricing at the pumps, reducing our reliance on fossil fuels could be one way to gain greater consistency in both the cost and supply of power.
“What’s really moving the needle is the federal carbon tax,” notes John Rathbone of Rathco ENG, who’s been working on a very neat greenhouse combined heat and power (CHP) project fuelled by biomass. These ideas are all part of a larger feature on geothermal energy (pg. 14), but they help to illustrate complexities around decarbonization decisions.
Based on proposed legislation, John predicts that natural gas will reach at least $170 per tonne by 2030. “That [price] is going to be seen as the new floor, whereas now we see it as the ceiling. As a greenhouse operator, what do you do when you know the cost of energy is going to be increasing considerably?”
that’s a sidebar piece. What’s truly remarkable is how Great Northern Hydroponics has been operating on a negative carbon footprint since 2008! And now that they’re switching from tomatoes to strawberries (marketed under Ever Tru Farms), they’re halving the amount of heat needed for their crop while reducing the need for strawberries imported from thousands of miles away (pg. 36).
Could alternative energy sources help power remote food production? Check out a second feature on geothermal which provides a more in-depth overview of the technology, alongside research based on more remote regions of Canada (Pg. 10).
If you’re hooked on this topic, don’t miss recordings of our spring energy webinars available at greenhousecanada.com/webinars There’s a two-parter on geothermal, one on biomass, as well as one on natural gas and decarbonization.
Finally, it’s time for me to say goodbye and hope that my work here has also moved a needle somewhere. This is my last full issue with Greenhouse Canada, though you may continue to see remnants of my work or features that I previously assigned. I’ve truly loved working
“What’s really moving the needle is the federal carbon tax.”
In another feature this issue, James Williams of 360 Energy summarizes the carbon prices and rebates offered to greenhouse producers in each province and territory. He’s also pulled together a table that illustrates the impact of the federal carbon tax rebate (80 per cent) on net costs per gigajoule (pg. 32).
For producers in Ontario, Guido van het Hof of Great Northern Hydroponics recounts the hurdles they faced in trying to obtain provincial relief on the carbon tax years ago, with the hopes of levelling the playing field with producers in B.C. and Alberta. It wasn’t until 2019, when the federal carbon backstop was introduced, that they finally achieved this. But
on the brand and all of its initiatives, so it’s a bittersweet departure as I embark on a new journey.
My heartfelt thanks to every grower who’s ever invited me into their greenhouse and everyone in the sector who has supported our work over the past 4.5 years. I’ve truly enjoyed meeting and working with each and every one of you, and I look forward to seeing the continued evolution of the Canadian greenhouse sector.
Now as my last wish, I implore you to register for Grower Day 2022 which is returning live June 21-22.
The Savoura Group has announced a $55 million investment in a new, 9-hectare greenhouse complex.
Located in Sainte-Sophie, Que., the municipality where the company was founded in 1995, the group says this is their largest investment to date as well as their largest construction project ever undertaken in the Lower Laurentians.
The construction is slated for completion this fall and will house conventional tomatoes, including varieties for which the company is known.
“This large-scale project will create about 100 jobs in Sainte-Sophie, which will generate significant economic benefits for our local businesses.
Furthermore, nearly 50 per cent of our territory is agricultural, we couldn’t ask for a better investment project,” says Guy Lamothe, Mayor of Sainte-Sophie.
The Savoura Group markets different varieties of tomatoes for the Quebec, Canadian and North American markets. Since December 2017, it has been marketing strawberries grown in Danville, Estrie and since fall 2018, organic mini cucumbers in the Saguenay.
With the investment of $55M in Sainte-Sophie, the group will cultivate more than 40 hectares in total on 12 production sites spread throughout Quebec.
Source: Savoura Group
Greenhouse Canada’s annual Grower Day event is back, live and in-person. Set for June 21-22 in St. Catharines, Ont., the event is jointly run by sister publications Grow Opportunity and Canadian Security For greenhouse ornamental and vegetable production, be sure to register for Day 1 (June 21). It’s all about future-proofing your business, featuring leading-edge research and innovative solutions
from industry experts. Topics and speakers include:
• Greenhouse predators: The new and the notable – Rose Buitenhuis, PhD (Vineland Research & Innovation Centre)
• The least energyefficient areas of your greenhouse and what to do about them –Chevonne Dayboll, PhD & James Dyck, PEng (OMAFRA)
• Handling plant stress like a pro – Michael Brownbridge, PhD (BioWorks)
• Growing on auto-pilot –Niki Bennett (OGVG) & Ron Hoek (Blue Radix)
• There’s something in the water – Fadi Al-Daoud, PhD (OMAFRA) & Thomas Graham, PhD (U of Guelph)
• Poinsettia Culture 101 –Gary Vollmer (Selecta North America)
• Adapting to a different mix – Brian Cantin (Berger)
• Horticultural lighting of the future – Rose
The 2022 Canadian Produce Marketing Association Convention and Trade Show welcomed over 3,600 attendees to Montréal, Que. in April.
A number of greenhouse producers took home awards from the show:
• New Technology Award: Open Plastics Project by The Star Group
• Organics Award: Natural Organics Grape Tomatoes by Mucci Farms
• Best First-Time Exhibitor Booth Award: ALLWays
Local Produce
• Best Island Booth Award: Mucci Farms
A complete list of winners is available at greenhousecanada.com. The next event takes place in Toronto, Ont., Apr 25-27, 2023. Source: CPMA
Séguin (Sollum Technologies)
Winners of the Top 4 Under 40 and Grower of the Year awards will also be revealed on June 21, presented by Greenhouse Canada For licensed producers interested in cannabis, add Day 2 (June 22) to your registration and learn about the latest in business, cultivation and everything needed to grow your cannabis enterprise.
Register at growerday.ca
Natural gas snapshot: Jan 2022
Source: Statistics Canada
Production of marketable natural gas increased 7%, year-over-year
MOST PRODUCTION was in Alberta (66.3%) and B.C. (32.4%)
Natural gas exports increased 3.8% from Dec
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Geothermal energy could help grow food security in isolated and Northern communities.
BY J. LYNN FRASER
Geothermal energy (GTE) is not new. The Romans, Japanese, Ancient Chinese, Ottoman Turks, Icelanders, Europeans, and New Zealand Maori have used hot springs for cooking, heating, and washing for millenia.1
It is classified as a clean, renewable energy source,2 harnessing the heat found within the Earth’s crust.2 GTE sources also heat water found at or near the Earth’s surface in the form of geysers, hot springs, steam vents, and underwater hydrothermal vents.3
When a GTE source offers energy above 120°C, electric power can be generated with the appropriate technology – this is referred to as deep or conventional geothermal.1 When ambient temperatures are at 5–30°C, they can be utilized by ground-source heat pumps to create heating and cooling for buildings.1 GTE, at this temperature, can be used for heating and providing electricity for greenhouses, fisheries, homes, and industrial
ABOVE
processes like lumber drying and processing pulp and paper.3,4
GTE IN CANADA AND WORLDWIDE
Worldwide, GTE produced more than 85,891 GWh of power in 2017 and this is expected to increase by 28 per cent by 2024.4 Canada does not currently produce electricity from GTE on a national scale. This is due to high upfront costs, the absence of strong regulatory and policy support, and competition from established and less costly sources of electricity.4 There is potential for GTE use in Canada for British Columbia, Alberta, Saskatchewan, Yukon, and the Northwest Territories, and this potential is being explored in a few projects.4,5
THE BENEFITS
“The beautiful thing about geothermal is if we have the energy to produce power. [If] the heat
In countries such as Iceland, greenhouses can be found harnessing geothermal energy.
“ “
We’re in a green industry—it only makes sense to be eco-friendly, and this closed-loop system we have [with East Jordan Plastics] right now is the best possible way to do it. It’s the best solution.
George Alkema, Owner and Manager LINWELL GARDENS
At East Jordan Plastics, sustainability is rooted in everything we do. Our closed-loop recycling program made it possible for Linwell Gardens—a chief supplier of plants for a major Canadian retailer and other local garden chains—to recycle hundreds of thousands of pounds of plastic containers annually. It’s an achievement that’s good for their business and even better for the environment.
source is managed properly, then there is no interruption to the ability to continuously produce power as long as the mechanical systems do not fail or require maintenance,” comments T.M. Gunderson, managing partner, Enerpro Engineering Inc.
GTE is considered ‘clean’ because usually only water vapour escapes, although some systems release small quantities of sulfur dioxide, nitrous oxides, and particulates.3 Using GTE could help Canada meet its CO2 reduction targets.5 A geothermal power plant can last for centuries. For the amount of power it produces, its surface square footage is small relative to wind, solar, or coal energy sources.3 It is an energy source that can supply clean, sustainable, non-carbon renewable energy that can be used for power, heating, and cooling with limited emissions.6 Examples of countries using GTE to heat greenhouses are Australia, Iceland, United States, Iran, Tunisia, Japan, and Europe.6
In isolated communities, GTE sources offer a cleaner alternative to diesel fuel used for heating and electricity,6 and could potentially power greenhouses. This
would aid local food production and food security while lowering food costs.6
A 2019 study in three communities, Resolute Bay (Nunavut) and Moosonee and Pagwa (Ontario), found that GTE could supply heat and power sources that were local and available yearround.6 The researchers concluded that geothermal-powered greenhouses offered local communities an increased quality of life and a cheaper source of fresh vegetables.6 The study concluded that the initial expenditure for the project was balanced by these advantages, along with cost-effective vegetable production, and reduced reliance on diesel fuel.
The Yukon is an area of Canada that can benefit from GTE.7 A 2016 report by the Canadian Geothermal Energy Association found that the territory can produce a minimum of 1,700 megawatts of geothermal capacity. The report stated that many communities, such as Whitehorse, Carcross and Teslin, had geothermal deposits capable of producing electricity using GTE.7
Maurice Dusseault, professor of Engineering Geology, University of Waterloo, notes “Yukon greenhouses
can be heated with water from hot springs, and if you drill down a couple of kilometres, you can find water hot enough to generate power.” Dusseault is cautious about being overly optimistic about GTE. He states “many factors [are involved]. For example, during what months are the greenhouses active? All year or March to October? In Victoria, B.C. or in Yellowknife, N.W.T.? How warm is the water and at what rates is it produced?” Considerations include the GTE source, how the energy is generated and how it is utilized, the community where the greenhouse crops are grown, as well as the crops themselves. “The solution depends on each application/ situation. What might be the optimum solution in Quebec will not necessarily be the best strategy for Saskatchewan,” states Gunderson.
In Canada, GTE use is constrained by location, quality, form it comes in, and distance from GTE source to end users.5,6 Many parts of Western Canada in particular have the conditions necessary for GTE use, while other areas do not.
Isolation increases need and installation costs. Research into geothermal-powered greenhouses, with Resolute Bay, Moosonee and Pagwa as the sites studied, found that geothermal energy applications require high capital investments.6 The cost to establish a greenhouse in Resolute Bay was estimated at ~$15M while in Ontario communities the cost was ~$5.7M.
Most Canadians receive their energy through a regional electricity source.5 This is one of the reasons why there is limited incentive to create GTE sources in the ‘south’ and non-industrial areas.
“Commercial geothermal power plants are not implemented in Canada, despite the fact that some provinces like British Columbia, Yukon, Alberta, and Saskatchewan have a suitable potential for using geothermal energy from hot springs,” observes Dr. Alireza Dehghani-Sanij, Department of Mechanical and Industrial Engineering, University of Waterloo.
“The optimum would be for a large agricultural greenhouse industry using natural geothermal heat, to generate enough power to operate the fans, the grow lights, the pumps and all the utilities and electrical equipment,
while using remnant heat to keep greenhouses at appropriate growing conditions.” Dusseault comments, “This allows for a 12 month/year greenhouse operation.”
In contrast to the source for GTE found in the Yukon, Dusseault observes how in Southwestern Ontario a “different type of ‘geothermal’ is widely used” – geoexchange. In southern parts of Canada, he notes: “Shallow groundsource heat pumps extract heat from the ground in the cool months, and dump heat into the ground in the warm months like a fridge but run in both directions.” He adds that this approach would not work in the north “where you have huge heat requirements and small ‘cool’ requirements. You cannot extract heat from the ground indefinitely; it becomes cold and very inefficient. You have to have some other heat source to recharge the thermal battery in the ground in this case.”
“Retrofitting is always possible, but it can be costly,” Dusseault comments. He adds that to adapt an existing greenhouse to take advantage of GTE, it is “best to design your greenhouses to use ground source heat pumps, and this means that you are using less energy. If a ‘warm water’ source from elsewhere (geothermal, waste heat from a nuclear reactor, from a plant) becomes available, the system can be easily and relatively cheaply modified to take heat from that source. If your greenhouse is 100 per cent electrically heated, retrofitting is more costly.”
Gunderson observes that the choice of GTE should be based on a “discussion between the greenhouse owner and an unbiased consulting company that can look at the energy options available, then select the optimal solution based on current and future growth of the business and future cost of energy.”
GTE’s future in Canada will be affected by Canada’s commitment to achieve net-zero emissions by 2050.8 Financial analysts comment that, while the demand for energy increases in Canada, there is a lack of new development to meet demand, although Canada is planning to use GTE for industrial use.9 There are opportunities for greenhouses to make use of the excess heat.
GTE-powered greenhouses have robust potential in Canada. Growth will
likely occur through partnerships for funding and implementation, and, to some extent, customization of food production and delivery.
1. Lund, J.W., Utilization of geothermal resources International Geothermal Association | 2. British Columbia. Geothermal Energy. | 3. National Geographic. Geothermal energy. | 4. Clean Energy Canada. Media Brief: Geothermal energy and its potential in
Canada. July 26, 2020. | 5. Government of Canada. Advancing the development of conventional and advanced geothermal energy. Apr 6, 2021. | 6. Kinney, C., et al, 2019, Energies. Geothermal energy for sustainable food production in Canada’s remote northern communities. | 7. Forrest, M. New report finds Yukon a hotspot for geothermal energy. May 13, 2016, Yukon News. | 8. Government of Canada. Netzero emissions by 2050. Aug 2021 | 9. Mordor Intelligence, Canada Geothermal Energy Market Outlook to 2021
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Geothermal vs geoexchange – deciphering what’s possible with each technology.
BY GRETA CHIU
As greenhouse producers look towards a net zero carbon future, alternatives to fossil fuels start to look increasingly attractive, and geothermal is one of them.
But there’s still confusion around the terminology. Vice-president of Geothermal Canada and president of the geothermal power project, Alberta No. 1, geologist Catherine Hickson, PhD, says it has been and continues to be one of the biggest problems she’s faced in the sector over her 40-year career. Unbeknownst to many, the term “geothermal energy” actually points to a range of technologies, each with differing capabilities and costs.
“At the one extreme, we’re talking about drilling deep wells and bringing those brines to the surface,” she says. Known as “deep geothermal” or “conventional geothermal,” this technology
taps into the earth’s intrinsic heat, often requiring the drilling of wells at least one to one-and-a-half kilometres into the earth. It can also take advantage of secondary heat, using the hot brine left from geothermal power generation of electricity.
At the other end of the technological spectrum is geoexchange, a form of shallow geothermal that uses the earth as a battery rather than a heat source. “We’re taking warm air and putting it into the subsurface [of the earth],” she says. “We still need to drill wells, but they’re very shallow – 60 metres, sometimes even less.” A closed-loop system, geoexchange typically takes anti-freeze or another fluid to carry the heat and circulate it through the pipes. “In the summertime, it’s hot, and the heat goes down into the ground. In the wintertime, it’s extracted and used for heating purposes.”
ABOVE The DEEP project in southeastern Saskatchewan is one of three major geothermal power projects in progress in Canada, and they’re looking for greenhouse growers to make use of the heat.
When evaluating the site for potential deep geothermal projects, there are two pieces to consider: the type of rock and the temperature of the geothermal brine. Generally, the lower the temperature, the greater the amount of fluid that needs to be flowed.
Alberta, Saskatchewan and northeastern B.C. are rife with highly porous rocks such as sandstone and limestone, which allow oil and gas to be brought to the subsurface. “And it’s the same with the geothermal brine. It needs to flow through the rocks,” Hickson explains. This is also why conventional geothermal makes sense in these regions. “They’re in a sedimentary basin and there is a good possibility that they can extract warm fluids from the subsurface to use for heating through a heat exchanger.” There’s also a high geothermal gradient in these parts. “What we’re looking at are brines that are in the 40 to 90°C range. That’s heat we can extract.”
For other parts of Canada, particularly in Ontario and Quebec, the rock on the Canadian Shield is crystalline – mostly granite and high-grade metamorphic rocks that do not flow fluid. Here, the geothermal gradient is not nearly as high, making it less commercially feasible for deep geothermal. “We actually have to create what’s called an engineered geothermal system where we create fractured permeability and are able to flow a fluid through that fractured rock in order to extract the heat,” she says. “We’re pumping fluid down one well, moving it through the subsurface, then bringing it to the surface and extracting the heat. Then the whole cycle starts again.”
She knows of several companies in this space, each with their own proprietary technology. “Unfortunately, those are not yet shown to be commercially viable,” she says. “The drilling technology has been proven, but whether or not these have longevity, particularly in a crystalline rock context, has not been shown.”
Nunavut and the Yukon are mainly on crystalline rock as well. The Northwest Territories contain a fair bit of crystalline rock but has areas of sedimentary basin stretching up from further south.
In terms of capital expenditure, the drilling involved in deep geothermal takes the cake. “But that provides you with longevity, so the heat can be extracted over decades – 40 to 50 years or
longer,” says Hickson. “High capital, but very sustainable, and with a very distant horizon. And that’s with good management.” As an added plus, the brines also contain CO2 that can be used by greenhouses – something she’s seen producers do in Iceland. For the more shallow geoexchange systems, she estimates that they would last at least 20 years, but at a lower capital cost.
While deep geothermal power projects may be geologically constrained, the more shallow geoexchange technology can be largely deployed anywhere across the country. Using the earth to store heat extracted from the environment, these systems can be built horizontally or vertically underground. Whether geoexchange makes sense for a greenhouse, however, depends on the operation’s needs.
“With heat exchanger systems this is acting like a thermal battery,” explains Adam Alaica, P.Eng, director of engineering and development at GeoSource Energy. He emphasizes the importance of heat balance, using a bucket of water as an analogy. “If you want to ensure you always have water available, you need to be putting in what you take out. If you’re only draining water out of that bucket, at some point in the future you’re going to run into an issue where you don’t have water available. The same logic applies to ground heat exchangers for large applications...If you put too much in the ground, it also overflows. If you take too much out, the bucket empties.”
“The rules of the game are the same on the greenhouse side as the real estate side,” adds John Rathbone, P.Eng, president of Rathco ENG. Having worked with greenhouse clients, he’s observed how the cooling mechanism often involves opening the vents in a traditional glass-roof greenhouse. Using the same bucket analogy, he likens it to water being constantly removed but not replenished. “There’s no mechanism for us to put water back in the bucket, which basically eliminates the geoexchange system from being viable. You’ll start draining your bucket, but once that bucket is empty, you’ve now essentially frozen your bore field and it’s no longer useful.”
However, for warehouse-style, indoor growing environments with opaque roofing and supplemental lighting, Rathbone has worked on the modelling for a number of them and sees
the opportunity. “In those types of systems…they are coolingdominant. The amount of energy that those lights put into the space? The numbers are astronomically large.” The capital budget is then focused on the air conditioning or cooling equipment –even in the winter – to offset the heat from the lights. “It gets even more complicated when we start looking at the loads associated with the heat of evaporation of water and the transpiration process on the plants, but we model all of these variables. This is where a more balanced system can be applicable to indoor growing.”
Alaica agrees that a typical greenhouse that primarily needs heating and uses free-cooling could be very challenging for a conventional vertical ground source system. “Other types of technologies that could be a better fit may include surface water heating and cooling, aquifer-based heating or cooling, or even a horizontal system, which has inherently a little bit more leeway in terms of balance as it interacts more with outdoor air.”
“When you’re running a greenhouse that only requires heating, there’s nothing to balance it. As engineers we need to think about what makes the most sense based off of available resources on-site or other technologies to provide that balancing function,” he adds. One option may be to leverage the ground source system as a true thermal storage vessel, coupled to waste heat sources. In a solar thermal set-up, the sun’s energy could be stored in the ground over the summer. “You leverage that heat during the winter and you size that system so that the bucket is sufficient to manage the imbalance on an annual basis, with the input coming from the sun rather than from your cooling load or facility.”
Having worked largely with commercial and residential heating applications, Alaica notes that open loop systems are also possible with water sources, such as aquifers, surface water heating and cooling, as well as deep lake water cooling. For smaller greenhouse facilities in particular, their groundwater source could potentially serve a dual-purpose for both production and heat storage.
“In order for solutions to be economical, they really do need to be customized to the use case. This might be one of the many reasons why decarbonisation is not easy,” says Rathbone. “If you are a conventional greenhouse grower with a glass roof, your primary source of energy is going to be natural gas. And you’re going to take two commodities out of that – heat to heat your greenhouses and CO2 to enhance yield.”
He notes how some facilities use large thermal energy storage tanks to save the heat generated from natural gas combustion, then release it at night after sunset. “All that works, but there is one giant elephant in the room called the carbon tax.” Based on planned legislation, Rathbone predicts that natural gas will hit $170 per tonne, if not more, by 2030 and beyond. “That [price] is going to be seen as the new floor, whereas now we see it as the ceiling. As a greenhouse operator, what do you do when you know the cost of energy is going to be increasing considerably?”
Although there are exemptions on natural gas use for greenhouse producers in most parts of Canada, whether the exemption will remain in place by 2030 is anyone’s guess. For those with combined heat and power (CHP) units, selling back to the grid may cause them to be labelled a power producer. “Any new natural gas power plant is going to pay the full carbon tax. When we modelled it out in terms of cost per kilowatt hour of producing electricity, the carbon tax was two-thirds of the cost,” Rathbone says, underscoring the importance of considering
taxation in the decision-making process.
From his perspective, there are five major categories of costeffective zero-carbon solutions at the moment – geothermal, biomass, industrial waste heat, sewer energy, and solar thermal. “Let’s not talk about hydrogen or nuclear because there just isn’t enough time between now and 2030, or arguably 2050, for these to become realistic, cost-effective at-scale solutions and technologies.”
For producers needing CO2 on top of heat and power, Rathbone’s top choice would be biomass. “If you are not needing the CO2, then a geoexchange or a deep geothermal system becomes a very compelling option, should your geology allow for it. But if you’re looking for CO2, there’s just one unfortunately at the moment.”
Once the carbon tax is factored in, their modelling has shown biomass to be cost-competitive with natural gas in combined heat and power production. “And that includes all the additional costs of transportation and storage of solid fuel. Not only are you not paying the carbon tax, but you’ve avoided a lot of other risks in terms of carbon policy, carbon pricing, and natural gas pricing.” In fact, going net-zero could open more doors to loans and grants. Working with several indoor cannabis producers in B.C., Rathbone’s energy conservation modelling work has helped them secure half a million in grants.
Because of the sheer volume of energy needed, Rathbone expects the carbon tax to hit producers hard. Three years ago, he and his team embarked on their first greenhouse project and it was eye-opening. “I thought we made a unit conversion error because the [energy] numbers were so large,” he says. It’s
why he emphasizes the importance of understanding the risks and opportunities amid a changing energy landscape. This way, operators are better prepared to make decisions within the next year or two in how they could build out their infrastructure to support their business plans.
Last year, his team completed an eight-month pre-feasibility study with a greenhouse vegetable grower. If all goes according to plan, it could very well become the largest biomass-fueled CHP power plant in the world. They could sell the extra electricity and CO2 and potentially help decarbonize other greenhouses in the region as well. Pending additional studies, the build is projected at 240 acres per year for 10 years, with goals to begin construction in 2023.
At the end of the day, the choice of energy source comes down to the structure being heated, as well as its heating and cooling demands. Rathbone says it’s important to model those energy flows not only on an annual basis, but also on 20 to 30-year timelines.
When it comes to conventional geothermal, there’s a difference between generating electricity versus heat.
To generate electricity, the brines typically need to reach at least 110°C, much more than what’s needed for heat only. From this high temperature fluid, thermal energy is extracted to produce power through an Organic Rankine Cycle (ORC) which creates electricity. However, the fluid post-ORC is still hot, albeit lower than what’s needed for generating electricity. Putting this cooler fluid through a heat exchanger then extracts the remaining
heat for district or industrial heating, including greenhouses. Once the heat has dissipated, the cold flue, measuring below 20 °C, is injected back into the subsurface. “We’ve extracted every BTU of energy. It just makes absolute sense to have that secondary heat being used,” says Hickson.
Currently there are three conventional geothermal power projects being developed and they are among the first to do so in Canada: the Tu Deh-Kah project in northeastern B.C., Alberta No. 1 in Greensview, and the DEEP project in southeastern Saskatchewan. All three have access to 120 °C brine within wells that run between two to four kilometres deep. More importantly, all have a large emphasis on food security, and Hickson hopes that they will be able to demonstrate the viability of using geothermal energy for greenhouses.
In the case of Alberta No. 1, Hickson says they’re actively seeking greenhouse growers who might have an interest in colocating with their 10-megawatt project. “We’re in an area that is close to transportation on a rail line. It’s in northern Alberta where food security is a major driver.” Plus, they’ve already signed an MOU with Analeada, a company that uses earthworms to compost on an industrial scale, producing a product that is already being used by the greenhouse sector. “We just need to attract somebody.” Through their calculations, Hickson estimates that the available thermal energy would be enough to heat 50 to 80 acres of greenhouses.
As for the geothermal power project by DEEP Earth Energy Production Corp (DEEP) in Estevan, Sask., CEO Kirsten Marcia says they’ve already drilled six wells to date and signed a 25-year Power Purchase Agreement (PPA) for 5 MW with SaskPower and negotiations are ongoing for an enhanced PPA. They have completed feasibility engineering studies and plan to have the first 35-megawatt facility commissioning in early 2025. Four of these 35-megawatt facilities are being planned for a total of 140 megawatt of geothermal baseload power.
According to Marcia, even just one of the four planned facilities would be enough to power 35,000 households. As for the secondary heat, “with average insulation in southern Saskatchewan, this could heat a one square kilometre greenhouse,” says Marcia. “We would sell heat to that end user, discounted to the price of natural gas with no carbon tax. This is clean, renewable energy with 24/7 supply.”
Saskatchewan currently relies on coal for 40 per cent of its power, a source that is being phased out by 2030. With the downturn in oil and gas industries, people are looking for jobs, particularly in energy-focused regions of southern Saskatchewan. “Wouldn’t it be wonderful to have a career in the greenhouse industry?” Marcia proposes. “I’m from Estevan, and I’m passionate about the idea of economic diversification for this area. We think geothermal power generation married with end users – whether it’s greenhouses or aquaculture, you name it – that could create a huge energy ecosystem. Marrying clean energy with food security could be very impactful.”
In B.C., the Tu Deh-Kah Geothermal project, aims to provide seven to 15 megawatts of power. Previously known as the Clarke Lake Project, this initiative is led by the Fort Nelson First Nation community. Similar to the other two projects, there is a keen interest in using the waste heat for other purposes including increasing the region’s food security and potential for agricultural exports.
“We have to be big, in order to be cost effective. That’s why district heating, hectares of greenhouses – that scale of project is
what we can do in deep conventional geothermal,” says Hickson.
In addition to collaborating with existing geothermal power projects, there is another possibility for lowering capital costs by taking advantage of pre-existing wells.
“We’ve put in a proposal to the federal government to look closely at suspended wells, and specifically in Alberta,” says Hickson. Differing from abandoned wells which have been plugged and sealed over by cement, thousands of paused or “suspended” wells currently exist in Alberta and could be re-entered for geothermal. “We’re going to look at not just the well temperature, but at proximity to roads, habitation, and an industrial park that might be appropriate for establishment of greenhouses or composting facilities.”
While electricity can be easily transported thousands of kilometers away via wires, heat will dissipate as it travels. For a greenhouse to use the heat from a suspended well, they would need to be located within a 10 km radius. “Part of our filter for this review is looking at the individual location of the well, drawing a 10-km circle around it, and seeing what’s [there].”
From deep geothermal to geoexchange systems, any would be potentially helpful to reducing greenhouse gas emissions, as well as reducing operating costs in time. “In Canada, you always have ground under your feet and you often have a lot of water available. There’s always going to be an application for geothermal in some shape, size or form,” says Alaica.
For more, watch the two-part geothermal webinar with Catherine Hickson and John Rathbone, available at greenhousecanada.com/ webinars.
Greenhouses in the Netherlands and Iceland have successfully harnessed geothermal, but the situation is very different for both countries.
“The neat thing about the Netherlands … is it’s a low temperature resource, very similar to what we have in the western Canadian sedimentary basin,” says Catherine Hickson. “It’s actually lower temperature than what we’re dealing with, and in most cases, has no possibility of producing electricity, but it’s being used for direct heat.” Repurposing wells in close proximity, they also have hot brine as well as a much greater population density. “That’s why it works in the Netherlands.”
Having spent much time working in Iceland, Hickson has witnessed a stark change in locally grown produce. Where it might have been difficult to secure potatoes and onions in the early 90s, that is no longer the case today. “The greenhouse industry has taken off there and it’s due to accessibility to a high quality resource and a market.” With a population of around 350,000, this change wasn’t likely driven by domestic need as much as it was propelled by tourism with 1.5 million visitors per annum.
“The cost of our energy is much less expensive than in Europe,” adds John Rathbone. “We’re spoiled here in North America and even more so in Canada with [our] natural resources. It becomes a challenge to try and motivate companies and individuals to focus on decarbonization and not be wasteful with energy. What’s really moving the needle is the federal carbon tax.”
Urban vertical retail farm finds ways to start up.
BY JANELLE ABELA
The agricultural industry in Canada is varied and constantly evolving, and this evolution is happening at an exponential rate due to the diverse intersectionality of up-and-coming innovators in the space.
For the founder and CEO of Ortaliza Farms, Carina Biacchi, finding space in the industry has been challenging but she credits local resources for entrepreneurs as much-needed support towards her success. Biacchi is an immigrant to Canada from Brazil, learned English as a second language, and is one of the agricultural industry’s newest, most driven changemakers.
Coming to Canada, Biacchi transitioned from her corporate career to a start-up entrepreneur.
ABOVE
She started Ortaliza Farms in Kingsville, Ont. in 2021, alongside her co-founder, Alvaro Fernandes, an agronomist engineer, and controlled environment agriculture (CEA) specialist.
“Ortaliza is an urban vertical farm store, a first-of-its-kind in Canada, and we grow and sell more than 65 varieties of microgreens directly to consumers,” describes Biacchi. Vertical farming uses automated technology to grow crops in vertically stacked layers. Ortaliza has taken this concept and added a storefront for consumers.
“Vertical farming is a rapidly up-and-coming industry within agriculture,” says Biacchi, and it reinvents the farm-to-table style of consumption.
At Ortaliza, the entire space totals 850 sq.
Carina Biacchi, Founder and CEO of Ortaliza Farms, a vertical urban retail producer in Kingsville Ont. They currently produce more than 65 varieties of microgreens.
ft., producing about 20 kg of microgreens per week, which represents 25 per cent of their production capacity at this first location.
“A vertical farm store is a concept where we integrate the practices of vertical farming with a direct-to-consumer model, creating a space where customers can see the production and experience the beauty of freshness, like having their greens harvested on the spot,” says Biacchi. “With this concept, we are able to reduce food mileage and food waste, while delivering the freshest products, year-round, that will allow consumers to get the most value in terms of nutrient content and flavour.”
In the early phases of development, Biacchi faced difficulties accessing capital.
“The combination of being newcomers and trying to create something entirely new within the industry (micro-farming in a retail space), presented barriers to initial funding,” she says. “It has been challenging to meet like-minded people and to find tailored mentoring. Agriculture is a completely different beast from a typical tech company, and at the same time, being an agtech startup makes you completely different from traditional farming.”
For the horticultural sector to grow, Biacchi’s case illustrates the importance of embracing new ideas and opportunities.
“So far, we’ve been able to fund our first MVP-like (minimum viable product) location with the help of Futurpreneur and BDC loans – although we were only able to access higher rate loans since we are newcomers.”
But there are regional resources that have stood by Ortaliza during its conception, to which Biacchi attributes some of her
startup’s successes, including WEtech Alliance, who connected them with resources and support.
WEtech Alliance is one of 17 Regional Innovation Centres across Ontario, serving the communities of Windsor-Essex and Chatham-Kent. The organization’s mission is to help grow tech companies and innovation. To support growth for entrepreneurs in the greenhouse sector, WEtech provides one-on-one advisory services, access to mentors and experts, as well as connections to investors and funding opportunities.
Adam Castle, director of venture services at WEtech Alliance, describes the criticality of the Canadian agricultural sector in recognizing and utilizing domestic technology.
“The majority of agricultural technology currently being used by Canadian farmers is imported. When [the] equipment breaks, the closest technician or solution might be over 6,000 kilometres away. As food sovereignty, security, and sustainability become a more frequent focus of national policy and sentiment, we must look at supporting Canadian technology solutions as an investment that fortifies the ability for Canadian Agriculture to tackle challenges in real time,” he says.
Castle also implores the necessity to ‘shop local’ by utilizing and purchasing products or processes that are fuelled by Canadian innovation. “The heart of innovation is empathy and understanding. At the heart of empathy and understanding is a relationship. By buying from Canadian technology vendors, we’re opening the doors for innovators to get a first-hand look at Canadian agricultural challenges. This virtuous cycle of working
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closely to understand pain points ultimately leads to technology being custom-made, and purpose-built for Canadian needs. Better relationships with suppliers create better outcomes.”
Awareness of the changing market has allowed Castle to realize the range of new technologies and methods that are coming out of diverse markets. Serving diverse populations could support a pivot that responds to change in consumers and market demand.
As these local relationships develop, resources for entrepreneurs must coincide. Biacchi urges the development of spaces for agtech startups to learn and grow, including support from existing horticultural growers in the form of partnership and collaboration. Biacchi says that these spaces should allow entrepreneurs to “work with and learn from people who have gone through or are going through the process, people who understand ‘ag’ language and [those] who share the same growth mindset.”
“You’re never done evolving as a startup, as an entrepreneur, or as an individual,” Castle adds. “But as a service provider in an entrepreneurial ecosystem, we must always remember that our programs and resources require iteration too.” Diversity, equity, and inclusion have become prominent on WEtech’s radar as the region’s population diversifies and the needs of entrepreneurs change.
Recent findings from the 2022 RISE Windsor-Essex Female Entrepreneurship Needs Assessment report “underscore the significant strides that have been made in becoming more accessible to a broader demographic within the community. The same report, and others like it, also underscore how much work still needs to be done to ensure that diversity, equity, and inclusion are being built into the foundations of our network, in meaningful and tangible ways,” says Castle. Support from growers isn’t just a helping hand to a competitor; it’s a collaborative relationship that moves the needle within the industry. There is no time to wait because change is looming in the Canadian agricultural industry and the sector must evolve.
“Canadian agricultural food exports are determined to reach
Their 850 sq. ft. space produces around 20 kg of microgreens per week, which represents just 25 per cent of their production capacity.
$75 billion by 2025. Our farmers feed the world, but they can’t do it alone. As the climate crisis deepens, supply chains struggle to return to pre-pandemic functionality, and the global agricultural labour shortage grows, Canadian agtech will play a vital role in helping chart a path forward for our country’s most foundationally important sectors,” predicts Castle. To maintain a leading position, growers must integrate the unique decision-making, problem-solving and critical thinking of new entrepreneurs, such as Biacchi.
What’s next for Ortaliza? They are working hard to establish and grow an entirely new business model within the industry using their unique approach of direct-to-consumer vertical farming.
“Our focus is now on tech development, sales traction, and preparing to scale,” says Biacchi. To aid in the growth and success of entrepreneurs like Biacchi, it is critical for those in the sector to listen, welcome diverse entrepreneurs to the table, and work collaboratively for sector growth
Janelle Abela is the founder of Diverse Solutions Strategy Firm and a business advisor for WEtech Alliance. Contact her at janelle@ diversesolutions.ca
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What it means to be regenerative organic and why it’s an idea worth considering.
BY SAMANTHA MILLS
What is regenerative agriculture?
While there are no set definitions in the legal or regulatory sense, the goal of regenerative agriculture is to farm in such a way that has a net positive effect on the environment and/or social aspects of society. Whether it’s restoring soil health or contributing to improvements in our climate, this holistic practice aims to leave the Earth in a better state than before, so the next generations can continue to farm sustainably.
Regenerative agriculture differs from organic agriculture. The latter is a term that does have legal and regulatory implications in Canada. To qualify under Canada’s Organic Certification Standards, a greenhouse operation would need to grow crops without synthetic pesticides and in living soil, among other factors. Crops grown
under hydroponic systems and/or with the use of supplemental lighting, heating or CO2 enrichment would not be eligible.
Combining two ideas rooted in like-minded goals, the term regenerative organic agriculture was coined by Robert Rodale in the 1980s. Both Robert Rodale and his father J.J. Rodale were pioneers in sustainable agriculture and their early experimental work would grow into the Rodale Institute, a centre dedicated to the study of organic and regenerative farming practices.
Robert Rodale first combined the two farming practices into regenerative organic agriculture in 1989. In the field, regenerative organic farming typically involves the use of cover cropping, managed grazing, as well as reduced tillage or no-tillage to improve soil health and to promote
ABOVE At Erieview Acres in Kingsville, Ont., the certified-organic operation uses regenerative practices that sustain soil health, including the use of cover crops.
environmental sustainability.
In 2017, the Rodale Institute launched the Regenerative Organic Certification (ROC) program in the United States which outlines standards and best practices. While it is possible to apply for Rodale’s ROC program in Canada, few Canadian farms are ROC-certified. Still, there are Canadian farmers who practise regenerative organic agriculture as a way to respond to the challenges of the climate crisis. The question is, what role do greenhouse growers have in the regenerative organic movement?
Both conventional and organic greenhouse growers employ sustainable practices that can reduce a greenhouse’s environmental impact, such as using renewable energy and recycling rainwater. However, there is a growing focus on more radical solutions such as reducing carbon emissions, removing carbon from the atmosphere through soil carbon sequestration, and rebuilding soil health that has been lost through years of degradation.
These goals, especially rebuilding soil health, are shared by both organic and regenerative organic agriculture. The importance of soil health to organic agriculture is illustrated by the Canadian General Standards Board’s Organic Production Systems which prohibits the use of soilless practices like hydroponics and aeroponics. The standards also specify soil composition standards that include the ratio of minerals, compost and biological fractions which must be used by organic farms. Organic greenhouse growers use, reuse, and amend this distinct blend of soil, just like outdoor organic farmers. Regenerative organic
greenhouse growers could use similar methods to improve their soils; however, unlike organic, there is no specific set of standards guiding them, just the goal of continuously building soil health. Though greenhouse soils are not necessarily integrated into the land, applying regenerative organic principles in production still has environmental benefits.
Much like organic farming, regenerative organic farming aims to improve the health of the surrounding ecosystem, with a primary focus on improving soil health. As such, there is an ongoing debate about whether the goals of regenerative organic agriculture are compatible with greenhouse growing. To find out, we asked Emily Gantz, Program Manager of Organic Consulting at Rodale Institute in Kutztown, PA, about the relationship between regenerative organic and greenhouse growing.
Q: Can the goals of regenerative organic farming (improving soil health and subsequently soil’s ability to draw down carbon from the atmosphere) be realized in a greenhouse system?
A: Soil is really what it comes down to. Under the Regenerative Organic Certification (ROC) program, Soil Health standard 2.5: Soilless Practices states that “aquaponics, hydroponics and other soilless practices are not eligible for ROC” and “container growing where crops are never integrated into a field for the majority of a crop’s life is not eligible for ROC.”...However, greenhouses still play a crucial role in the regenerative organic movement in two ways:
Put life back in the soil
Mycorrhizae & Trichoderma Inoculant for:
• Seed treatments, transplants & established crop root drench
Increased crop performance with improved:
• Germination rates
• Root absorption area
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Concentrated liquid seaweed extract from Ecklonia maxima
• Apply as a root drench or foliar spray
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• Cell expansion & fruit fill
Erieview Acres operates 12.5 acres over two greenhouse sites. Pictured here are their tomato and pepper crops.
1. Utilization of greenhouses to produce annual seedlings that will spend the majority of their life in the soil.
2. Utilization of greenhouses to manage temperature, water and overall growing conditions, as well as increase yields per unit area for crops that are being grown in soil under greenhouse cover.
Q: What are the key issues that stand in the way of greenhouse growers transitioning to regenerative organic farming?
A: Farmers wishing to adopt regenerative organic practices would face barriers if they are currently using soilless practices or container growing. These operations would be ineligible for certification.
The ROC program looks at the overall production of the operation. The operation would be required to implement regenerative organic practices and an effective crop rotation plan, manage vegetative cover and reduce waste. These practices would need to continually improve year-over-year.
Q: Since some greenhouse growers never intend to move their crop outside, what are some regenerative organic techniques a greenhouse could employ on exclusively indoor crops?
A: There are many – cover cropping, reduced tillage, use of onfarm inputs and recycling of nutrients, use of plant and animalbased inputs vs. synthetic chemicals, recycling of water captured on greenhouse roof, and increasing diversity in their crop rotation.
Though regenerative organic greenhouse growing presents unique challenges, it also has the potential to offer promising solutions to the problems faced by farmers as a result of climate change. Organic greenhouse growing can offer a useful framework or starting point for farmers interested in adding regenerative organic practices into their agricultural system.
“Organic is a way of growing that provides environmental, health, and social services to all Canadians. Employing some regenerative practices, even without certification, along with
certified organic practices is better than doing nothing at all,” says Norm Hansen, Director of Research and Development for certified-organic greenhouse vegetable producer, Erieview Acres in Kingsville, Ont. “I am an organic grower. I am on a lifelong journey of learning and the idea is to set as many growers on that journey as possible.”
Erieview currently operates 12.5 acres over two greenhouse sites. Although Erieview Acres isn’t ROC-certified, the operation uses some regenerative organic practices in the greenhouse. Rather than directly applying specific nutrients to the rootzone, the grower ensures that there are high enough nutrient levels in the soil in non-soluble form, such that the microbes in the soil can make them available to the plant as needed. The soil blend is important not only for nutrients, but also to provide habitat for soil life, says Hansen. The living mixture of soil and compost is consistently re-evaluated and tailored to support this balanced ecosystem
By adopting regenerative organic principles, greenhouse growers can cultivate healthy soils and improve the soil’s capability of absorbing excess greenhouse gas (GHG) emissions. With these in mind, increasing the capacity for greenhouses to join the regenerative organic movement is an idea worth exploring.
Samantha Mills is the communications coordinator at the Organic Council of Ontario, which represents the province’s organic sector. To learn more about the supports available to Ontario farmers interested in transitioning to organic and regenerative systems, visit organiccouncil.ca.
Acknowledgements: Special thanks to Emily Gantz and Norm Hansen for contributing to this article. Farmers interested in receiving consulting services for the organic and regenerative organic regulations can contact the Rodale Institute directly at 610-683-1416 or e-mail at Consulting@rodaleinstitute.org. Learn more at RodaleInstitute.org/ Consulting.
Note: Quotes in the article have been paraphrased for length. With files from Ontario Greenhouse Vegetable Growers
Early biocontrol practices can help prevent the spread of whitefly to different areas of the greenhouse. They also help skew the Bemisia population towards the B-type, rather than the Q-type which is more resisistant to insecticides.
BY GRETA CHIU
Ontario poinsettia growers saw a surge in whitefly pressure last season.
During a discussion at the Sawaya Gardens’ poinsettia trial open house in Waterford, Ont. last November, a number of growers attested to high whitefly (Bemisia tabaci) pressure at various points during the past season. Some found them in earlier weeks, others in later shipments.
For Jeffery’s Greenhouses in the Niagara region of Ont., they observed at least five times as much whitefly pressure as they did in previous years while still on the rooting bench, early on in propagation. Shipments to their greenhouse were hitand-miss. Some turned out to be highly infested while others were completely clean. Head Grower Albert Grimm says they were forced to throw away a few hundred cuttings after thoroughly inspecting each cutting tray. Based on their initial observations from weeks 30 to 32, they ramped up their biocontrol program accordingly and doubled their spending to curb a potentially devastating whitefly problem later on in the season.
“Very early scouting using methods that are suitable to detect whitefly nymphs, long before they show up on yellow sticky cards, were crucial,” Grimm said.
said Mike Short, IPM consultant and owner of Eco-Habitat AgriServices. “If you’ve been using biologicals all the way along, what you’re doing is you’re mitigating the amount of whitefly migration and intensity in the crop.”
From experience, Short has found that biological control methods help keep whitefly from spreading to different
Of the growers who shared their methods for whitefly control, some used dips in BotaniGard and/or Kopa insecticidal soap, depending on their past degree of success with these products. However, many underscored the importance of scouting and starting a biocontrol program early on.
“If you didn’t use biologicals, chances are you would have to start spraying by September then spray every week after,”
varieties in the greenhouse. Furthermore, these practices can help skew the proportion of the whitefly population towards the B-type rather than the Q-type species of Bemisia, where the latter is resistant to most insecticidal sprays. Starting with a biological control program early on would help improve the efficacy of sprays in the fall for a final clean-up of poinsettias, if needed.
[Left]Whitefly nymphs (1st instar) one week after sticking. These nymphs are not yet visible without a magnifier. For this reason, Jeffery’s does not start scouting the leaves until around 14-18 days after sticking.
[Right] Delphastus larva feeding on a whitefly nymph.
A number of poinsettia cuttings suppliers were also present, giving growers an overview of pest management strategies used in their offshore facilities. They continuously monitor for whitefly on plants, with many relying on chemical-based inputs to keep them clean.
At Dümmen Orange however, technical support specialist Rick Rabb explained that the supplier changed up their approach to pest management by implementing biological control on their poinsettia. In 2015, the company introduced their GreenGuard program, which builds on foundational IPM principles, monitoring pests regularly and using non-chemical methods when possible. They use spot sprays along with biofriendly pesticides throughout the growing season up until harvest.
“We’re making great progress on our biological control,” he said, pointing not only to the poinsettias, but to other crops as well, including their spring annuals.
Over the past six years, Dümmen Orange had reduced their chemical inputs by 80 per cent. Last year marked the first full season where their poinsettia in Ethiopia were grown entirely under the GreenGuard program, and their farm in El Salvador will soon follow. They use predatory mites Amblyseius swirskii or Transeius montdorensis to target whitefly eggs, parasitic wasps Encarsia formosa and Eretmocerus eremicus to manage whitefly larvae, as well as entomopathogenic fungi Beauveria bassiana and Lecanicillium muscarium to manage both whitefly adults and larvae.
For diseases, they use the biofungicide Bacillus subtilis to manage Botrytis and Alternaria, as well as Trichoderma harzianum to manage root diseases.
For growers who discover infested shipments, one key suggestion was to immediately advise the supplier. “If we can identify the bench, we can either treat that bench or take it out of production,” said Gary Vollmer, Selecta One’s technical support manager. Using the crop ID tags that arrive with each
shipment, his team would be able to trace the contents back to the original house and bench.
As for the 150 different varieties trialled at Sawaya Gardens, plants were propagated by Linwell Gardens then sent to trial organizer Melhem Sawaya. The greenhouse consultant and owner of Focus Greenhouse Management decided not to use chemical pesticides and growth regulators. The result? Very clean plants – apart from one or two varieties in white, a colour that has historically attracted more whitefly than others.
So far, Ference insecticide (cyantraniliprole) seems to be the only pesticide that continues to be effective against the Bemisia whitefly. The product was registered for greenhouse ornamental use in Canada back in 2020.
However, since the Q-type whitefly has been known to develop resistance rather quickly, Jandricic has concerns about the longevity of this insecticide, particularly as new chemistries for whitefly are hard to come by.
Cary Gates, pest management director of Flowers Canada Growers (FCG) says there are other potential insecticides coming to Canada for these uses in the future.
One already available in the U.S. is Rycar (pyrifluquinazon), which was submitted for registration with the PMRA in 2019 for whitefly and aphid management in greenhouse ornamentals, as well as a number of greenhouse vegetable crops.
“Flowers Canada has been working with Nichino to get this into Canada since 2010 but there were a number of barriers,” says Gates. He hopes to see it registered for 2022. “With that said and despite the long timelines, we’re really grateful to both Nichino and Belchim for supporting the greenhouse industries. This will be a very welcome product for growers.”
“We started our biological program as soon as the plants were planted at week 35,” said Tara Celetti, biological program specialist at BioWorks Inc. Tasked with managing pests for Sawaya’s trial poinsettias, the team put out Dalotia coriara (previously known as Atheta) and Stratiolaelaps scimitus (previously Hypoaspis miles) to begin with. “These two work together to control fungus gnat larvae, shoreflies, as well as thrips pupae that are in the soil.”
They also released Encarsia and Eretmocerus, two small parasitic wasps that feed and parasitize both the Bemisia and greenhouse whitefly.
“By week 44 we found a hotspot [for whitefly],” Celetti recollected. “We released Delphastus which is a little beetle that feeds on whitefly eggs. We only use them for hotspots. You wouldn’t use it as a preventative treatment.”
At Jeffery’s, Grimm said they also released Delphastus in addition to Amblydromalus limonicus and Encarsia “Delphastus feeds on eggs before it eats anything else,” he said. “This year, we put four Delphastus per square metre on the crop…. You won’t see reproduction, but they clean up the eggs.” For them, the results weren’t noticeable until three to four weeks after release, and they continued this treatment all the way to the end of the program.
The absence of reproduction in Delphastus is normal, even though the system is doing its job. As Ron Valentin, then director of technical business at BioWorks explained, “Delphastus needs to eat 160 whitefly eggs per day to start reproducing.”
As for Encarsia and Eretmocerus, he said, “if you look between the two wasps, Encarsia does approximately four, maximum five, L1s – the first larval stage of whitefly – per day. Eretmocerus can do twenty to thirty L1s per day.” There’s a significant difference in feeding capacity between the two biocontrol agents.
While both wasps will feed on both the greenhouse whitefly and Bemisia, Valentin says that parasitism on the latter really requires Eretmocerus. “[With] Encarsia, maximal parasitism on Bemisia is less than 17 per cent,” he says in a follow-up email. This is not considered “control.”
Celetti emphasized the importance of prevention and early detection. “Scouting is really important… If you notice that there is whitefly, mark that plant as having whitefly, whether it was 1 or 100.” She suggested calculating percent infestation using a minimum of 100 plants. “If you can do it by variety, that’s ideal. Then calculate what percentage of your plants have whitefly.”
While some growers shared less-than-ideal experiences with certain dipping methods, Michael Brownbridge, PhD, biological program manager for disease control at BioWorks, underscored the importance of ensuring the correct BotaniGard and insecticidal soap rates for dipping. Dipping at the recommended spray rate for insecticidal soap could potentially lead to plant damage.
Using BotaniGard at the label rate in a 0.5 per cent (v/v) solution of insecticidal soap, he said, “probably eliminates around 70 to 75 per cent of whiteflies through one dip.” Based on studies in other ornamental crops, he speculated that insecticidal soap may also help reduce any chemical residues lingering on the cuttings. “Knocking your whitefly population back early helps your biocontrol program succeed later on.” Horticultural oils like Suffoil-X– at a 0.1 to 0.25 per cent rate,
significantly lower than the recommended spray rate – are another suitable option.
For growers concerned about Erwinia, Brownbridge said the benefits of dipping in insecticidal soap likely outweigh the risks. “You have to have such a high level of Erwinia bacteria to even infect the poinsettia cutting”.
Sarah Jandricic, PhD, greenhouse floriculture IPM specialist at the Ontario Ministry of Agriculture, Food and Rural Affairs agrees. “The chances are very, very low.” As she tells Greenhouse Canada, it’s important to use common sense around sanitation, changing the dip solution between days, at a minimum. Previous research by the team at Vineland Research and Innovation Centre has shown the risk of Erwinia to be very low, and recommends sanitizing and cleaning the dip bath before and after use.
As for phytotoxicity, Jandricic hasn’t seen any direct correlations with soap use. However, she notes that it’s important to rinse off the soap properly after dipping, simply by putting the cuttings under mist as soon as possible, to reduce any lingering residues.
For a combination treatment of Kopa and BotaniGard against whitefly on unrooted cuttings, Vineland recommends 0.5 per cent Kopa + 1.25g/L BotaniGard WP. Rates may need to be adjusted based on crop sensitivity.
To see dipping rates developed by Vineland, a video of Vineland researchers performing the procedure, as well as Jandricic’s updated article on how, when and why to dip, visit greenhousecanada.com and ONfloriculture.com
What greenhouse growers need to know.
BY JAMES WILLIAMS
All greenhouse growing facilities in Canada are subject to some form of carbon price on their chargeable fuel purchases. Growers may also be eligible for various forms of rebates, depending on the province in which they operate. This brief guide is meant to help growers understand and navigate the rules.
A price has been placed on carbon emissions to speed up the adoption of clean fuels that do not emit greenhouse gases when burned. Using fuels like propane, natural gas and gasoline produces CO2, methane, and nitrous oxides. In the atmosphere, these gases act like a blanket, preventing the earth from radiating its heat into space. These gases are now retaining so much heat, they are altering the earth’s climate. To reduce the risks of climate warming, CO2 emissions must drop and eventually stop.
British Columbia was the first Canadian jurisdiction to introduce a carbon price in 2008. Other provinces subsequently introduced their own programs. The federal government initiated
a national Federal Fuel Charge (FFC) in 2019. The FFC is a carbon price on fossil fuels across Canada which increases over time, rising $10/T annually from 2019-2022, and then rising $15/T annually from 2023-2030.
The FFC applies in jurisdictions which either accept the federal program or fail to implement their own deemed acceptable by federal standards.
As noted in the table below, greenhouse growers in Alberta, Manitoba, Saskatchewan, Ontario, Nunavut and the Yukon are charged the FFC. In these jurisdictions, an 80 per cent point-ofsale rebate is available where all or a substantial fraction of the facility is used to grow vegetables, fruits, bedding plants, flowers, ornamental plants, tree seedlings, medicinal plants or other plants, and where gas is used exclusively to produce heating and CO2 for the crops.
Based on current regulations, CHP fuel use would be ineligible for the federal rebate. According to the regulations,
Newfoundland/Labrador
Nova
carbon program
carbon program
Fuel Charge
carbon tax
Cap and Trade Cap and trade pass-through
Prince Edward Island Federal OBPS
provincial offset rate on natural gas
for heating is exempt unless used in generator
carbon levy
exemption on marked fuels Quebec Provincial Cap and Trade Cap and trade pass-through Saskatchewan
OBPS
Fuel Charge (for greenhouse agriculture)
Fuel Charge
to 80%
to 80% Northwest
to 80%
Carbon pricing programs per province or territory, at a glance. *Note: Specific eligibility factors may apply and conditions may change. Please check local regulations for details.
Grow Yields & Profits with a Combined Heat and Power system.
Power your greenhouse with clean energy from natural gas and help reduce grow cycles.
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Compact modular designs for easy setup and quick deployment
FLEXIBLE POWER
Power your complete operation with electricity
OFF-GRID SOLUTIONS
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Electricity “on demand” when you need it with ability to run our systems with or without the grid, “island mode”
THERMAL ENERGY
Steam, hot water, hot oil, hot air, and energy for cooling
COST SAVINGS
Relief for escalating utility costs
Heat captured as by product of electrical generation and used in the process
OPERATION & MAINTENANCE
Local service and remote monitoring
CO2 FERTILIZATION
Improved plant growth through exhaust heat recovery
greenhouses can still claim the rebate for gas use at the facility and then self-assess the fuel charge for gas associated with electricity generation, although we advise greenhouses to work with the CRA to confirm how they require it to be done.
Provinces with their own carbon-pricing program are referred to as “non-listed provinces.” Non-listed provinces collect their own carbon charge and can provide their own incentives. There are variations between the federal and the non-listed provincial systems, depending on the incentives each provincial government allows.
The rules vary between non-listed provinces. New Brunswick may allow greenhouses to register as a farmer or silviculturist to obtain fuel purchase exemptions. Newfoundland and Labrador allow exemptions for certain fuel types when the fuels are used for purposes other than in an internal combustion engine. Greenhouses within those provinces should approach provincial authorities to determine if their operations will qualify for exemptions.
Quebec and Nova Scotia have cap-and-trade systems. In these provinces, the carbon charge is included in the price of fuel and there are no exemptions.
Greenhouse growers can reduce the impact of carbon costs on their bottom line. Their first step must be to determine how much energy they actually require. This includes reviewing the amount of useful heat and CO2 necessary for optimal production levels. Many growers discover that they use more energy than needed. Reviewing operations closely to lower energy use can identify potential conservation measures such as
This table shows how the cost per tonne translates to a cost per unit of gas, as well as what it means to greenhouses after netting out the rebate under the federal fuel charge.
Burning fossil fuels produces heat and CO2 – both of which are useful for greenhouse crop production. When a facility’s heat requirements exceed CO2 requirements, cleaner fuel sources for the heat can be considered. Examples include biomass, renewable natural gas or electric heating, or taking waste heat from nearby facilities. Note that biomass is generally exempted from carbon tax and carbon emissions programs on the assumption it would have emitted GHGs through decomposition. Office, warehouse and packaging areas are good candidates for electric heating as they do not have a CO2 requirement for crop production.
Greenhouses with lower heating requirements than CO2 requirements can consider purchasing liquid CO2. As carbon capture technology becomes increasingly available, capturing CO2 from nearby facilities and piping it into the greenhouse may become feasible.
Canada’s system of carbon prices and rebates is complex.
Note that for carbon reductions to be considered, they are required to be “permanent.” While the crops store CO2, the plants themselves are not permanent and can re-emit through the decomposition process. This is part of the justification for the 80% rebate on greenhouse fuel use.
Carbon charges are a reality for the foreseeable future, so understanding how energy is being used and knowing how much it’s costing are now critical requirements for every greenhouse grower. Learning to control energy use and to reduce CO2 emissions has never been more important. As costs continue to increase, greenhouses need to become more sophisticated in how they deal with energy and CO2 balances in their facilities. CO2 will always be required as part of the growing process, but greenhouses can take steps to ensure that they aren’t producing more than they need.
James Williams is an energy analyst at 360 Energy. He can be reached at james.williams@360energy.net.
Grower transitions greenhouse crop to meet rapid growth in market demand.
BY KAITLIN PACKER
At Great Northern Hydroponics in Kingsville, Ont., the greenhouse tomato and cucumber producer has replaced 25 acres of tomatoes with strawberries in a fixed gutter grow system. They’re planning for an additional 15 acres this summer with the ultimate goal of reaching 65 acres of strawberries by 2023.
Marketed under Ever Tru Farms, the vertically integrated operation is targeting a rapidly growing strawberry market with current distribution to Ontario and parts of the U.S. Loblaws was one of the major Canadian retailers who signed on with Ever Tru once production started.
Guido van het Hof, president of both Great Northern Hydroponics and Ever Tru Farms, first spotted the opportunity in strawberries after seeing potential improvements that could be made in their production from places like California, Mexico and Florida.
Breeding strawberries to withstand a long truck ride north to Canada can cause important properties to be neglected, including flavour, shelf life, fragrance and texture. “Retailers historically had a lot of shrinkage because often that berry was
already five, six days old by the time it got on the shelf,” says van het Hof. “Since we’re bringing these varieties into the greenhouse and producing a lot closer to market, we’re able to produce a much better flavoured berry in season, year-round.”
The journey wasn’t easy. They trialled for six years before taking the next big step into largescale commercial production. “We needed to gain knowledge and experience with varietal choice, cultivation practices, scheduling and development of a marketing plan.”
By choosing an ever-bearing variety, they will be in production 365 days a year for continuous product, rather than relying on multiple plantings. As Paul Mastronardi, vice president of sales for Ever Tru Farms, explains, most strawberries coming from California use short-term, Junebearing varieties that produce about three to four crops a year.
“Because we set up our own sales and marketing under Ever Tru farms, it is our ambition to pick, pack and ship the same day…so that we can pick product at the peak of its flavour,” says van het Hof.
Even before their venture into strawberries, Great Northern Hydroponics was already growing on a net negative carbon footprint by introducing combined heat and power (CHP) units back in 2008.
“A portion of the boiler heat that we historically needed to generate through the natural gas-fired boilers was displaced by the combined heat and power units,” says Guido van het Hof. “And because of the high efficiency of the [natural gas boilers], which is greater than 95 per cent, that heat displacement created a negative carbon footprint for us overall.” That calculation, he says, was performed by an engineering firm at the time.
Their greenhouse also makes use of the CO2 scrubbed from the flue gas as well as condensed from the high-efficiency boiler for plant fertigation, but this practice doesn’t give them extra credit. In fact, van het Hof was informed that plant sequestration of CO2 is merely considered a form of temporary storage. Once consumed, the carbon can then be released again via the human gastrointestinal system. The leftover biomass of the crop is often composted or landfilled, re-releasing greenhouse gases such as methane and CO2 in the process. “It’s irrelevant if I agree with that assessment or not, but those are the rules today,” he says.
As it stands, Ontario greenhouse producers are charged the carbon tax based on use, through the gas meter and at the point of its arrival to the greenhouse. There is no consideration given to the sequestration of CO2 by plant mass, nor the treatment of CO2 post-combustion, like the previous short-lived, cap-and-trade program that was eventually cancelled in 2018.
“The mindset was that, he or she who consumes the most amount of fossil fuel is the one who has to carry the highest burden from a financial perspective.” Previously, greenhouse producers in Ontario were unsuccessful in obtaining a carbon tax waiver, similar to the one that was available to greenhouse producers in Alberta and B.C. It wasn’t until 2019, when the federal government stepped in with its carbon backstop, that Ontario greenhouse producers achieved an 80 per cent relief on the carbon tax, applied on fuels used for heating and CO2 production.
Although the foundations of carbon taxation are motivated by good intentions, van het Hof is competing with foreign producers who are not subject to the same limitations. “As a Canadian producer, we have to call it a competitive disadvantage.”
~With files from Greenhouse Canada
Guido van het Hof and Paul J. Mastronardi have marketed their strawberries under Ever Tru Farms.
The operation expects to produce 30,000 cases per week to start, with the goal of ramping up to 45,000 cases.
Mastronardi sees a major opportunity for growing strawberries in the controlled environment of a greenhouse, and sustainability has been a key part of the conversation.
“We’re saving roughly 15,000 miles by growing greener strawberries all year-round,” he says. “We’re within an eight-hour window for delivery, and that ultimately leads to a fresher product for the consumer.” He points out that consumers are increasingly interested in knowing where their product comes from and how it’s grown.
Van het Hof says their approach to sustainability includes multiple layers, such as biological pest management, energy screens to conserve heat, night interruption lighting to enhance productivity, trials with LED lighting for better energy efficiency, as well as water recycling. “We use a fraction of the water compared to outside berry production,” he says, explaining that their irrigation system allows them to pasteurize the recirculated water.
What’s more, the strawberries are actually grown on a negative carbon footprint, and van het Hof says they’re finding new ways to further reduce it.
As with the tomatoes, they use the CO2 from their combined heat and power units as well as boiler heating system to feed their plants. What’s different is the natural gas required – the strawberries only need about half the amount of heat as tomatoes do. “We’re going to halve the gas consumption with strawberries versus tomatoes because they require half the heat.” With the increase in strawberry acreage planned for 2023 along with energy savings through the principles of Plant Empowerment, van het Hof says, “Slowly but surely, we’re almost at two and a half times of what the original carbon credits were with 50 acres of tomatoes back in the day.”
At Ever Tru Farms, the pursuit of innovation is as strong as their passion for the perfect strawberry experience.
“What feels so good about it is we have such a good story to tell from an environmental perspective, from a flavour perspective, from an overall berry experience,” says van het Hof. “We stand behind the product that we pump out. It’s clean. It’s wholesome. It’s pure, and it’s ever true.”
Growers face significant challenges in maintaining a homogenous climate throughout the entirety of their greenhouse.
With vertical air flow fans, ventilation jets pull in cool, dry air from above the screen and distribute it in a vertical direction.
BY KYLE EDMISTON AND ROBERT HANIFIN
Screen gapping, running supplemental lighting paired with light abatement curtains and high density crops are all contributing factors to heat, humidity, and uneven climate zones within a greenhouse. To maintain even climate zones and plant growth, while also faced with rising energy costs, growers are looking to find adaptive ways to manage the greenhouse climate. An excellent way to maintain balanced temperature and humidity levels throughout a greenhouse is with vertical air flow (VAF).
VAF fans are a simple way to distribute air from top to bottom inside the greenhouse, as warmer
ABOVE
air tends to stay at screen level. Furthermore, VAF fans provide more control in the distribution of air compared to horizontal air flow fans. By adding a jet component with the standard VAF fan, these systems pull in cooler, drier air from above the climate screen, and then evenly distribute this air in a vertical direction with the help of downward facing fans. This results in reduced temperatures and humidity.
As the area above the screen fluctuates in temperature based on outside weather conditions and vent position, VAF fans can be modulated to run at certain speeds to ensure the correct amount of air flow is distributed to maintain humidity and temperature levels. Connecting these jet and fan units to additional climate sensors gives the grower even more control over their grow
Demonstration of the use of vertical air flow to manage temperature and humidity. As shown above, the fan and jet pulls cool air into the greenhouse and distributes it evenly over the crop.
space, ensuring that each area of the greenhouse has the right amount of control for an even climate.
Simon de Boer, head of plant production at Schoneveld Breeding states that a uniform climate is their number one priority when considering greenhouse design and production.
“Uniformity was one of the most important starting points.” says de Boer. “Everything stands or falls with a uniform greenhouse climate, especially in a breeding company. That was our number one priority. A plant that is on the back of the table must grow under the same uniform conditions as a plant that is in the middle or the front of the table. After all, inequality in climate or cold corners can have an effect on the results of the breeding. And that’s just not what we want. We want to let the genetics speak.”1
To achieve this, the potted-plant producer consulted with an expert to select the right combination of climate screens paired with vertical air flow jets and fans. This combination, which allows ventilation through closed climate screens, has allowed for temperature, humidity, and energy levels to be in balance with one another, resulting in a uniform climate.
De Boer is one of many growers in the Netherlands who has found success in climate management through the use of VAF fans and jets. The same technology is now available to growers in North America. VAF fans and jets can be utilized in a wide variety of greenhouse types in addition to venlo. They are compatible with different greenhouse glazing materials, as long as roof ventilation is available.While most common in
larger, gutter-connected structures, they can be used in single frame greenhouses as well. There is no specific minimum gutter height that a greenhouse needs to have, but it is necessary that the crop height (especially in vine crops) is two to three metres below the fans to allow for full airflow. VAF fans and jets are relatively inexpensive to run. At $0.10/kwh, a paired fan and jet would cost less than $5 to run 12 hours per day for a week.
Many growers in the U.S. and Canada who could benefit from such technology still have not been exposed to it. The best course of action for implementing a VAF system into a greenhouse is to speak with an expert. Check with the seller of VAF equipment to learn what they offer in terms of assistance. VAF jets and fans are typically installed at a 1:2 ratio, with up to 20 jets per hectare for vine crops using supplemental lighting. Your chosen seller should be able to work with the VAF company to plan a layout specific to your greenhouse and crop.
1. Stöver, H., 2020. ‘Uniform climate is the number one priority for us”. [online] www.hinova.nl. Available at: <https://hinova. nl/wp-content/uploads/Schoneveld-Breeding-_-bloemisterijeditie-7-2020.pdf> [Accessed 12 April 2022].
Kyle Edmiston is the business development manager of the ClimaFlow division at Svensson. Robert Hanifin is a Svensson climate consultant.
Luke Den Haan
Den Haan Greenhouses, Lawrencetown, Nova Scotia
“Several years ago, I traveled to Delphy in Holland and it opened my eyes to the idea of using LED technology for winter production. We decided to go with the best on the market, Philips LEDs. In 2020, we installed Philips LED toplighting over our cucumber crop and Philips toplighting and a single row of Philips interlighting in our tomato crop. The production forecasts have worked out exactly as Signify predicted with a 40% increase. And growing under LEDs took out the peaks and dips in our production. We are very satisfied with the results of growing under Philips LED lighting.”
Inrush current, wattage, power factor and harmonics of your LED fixture could significantly change your project costs.
BY JOLI A. HOHENSTEIN
As more growers around the world implement LED lighting in their greenhouses, project managers and light strategists are encouraging them to gather all the facts about a fixture before making an impulsive decision that could cost them more in the long run. Often, an electrical contractor details and designs a lighting project based around a specific fixture, but after the project design is completed, a grower chooses to purchase a different or less expensive fixture for the contractor to install.
“Growers may end up paying more in total project costs because the specifications of the product purchased for the installation deviated from the product for which the project was designed. Perhaps they saw the lower price of a fixture and ran with it,” says Mark Pedersen, President/CEO, Climatrol Solutions Ltd., Surrey, British Columbia. “We want everything to run seamlessly, and it is very important with a lighting fixture that we have the complete information, just like any other component purchased for their facility. We need to be sure it is going to work for their greenhouse and not cause an issue to their electrical or hydro-electrical system.”
panels, high-voltage sub feeds and transformers, among other components. Without exact specifications, small deviations from the initial plan can add up to huge expenses as electric panels may need to be reconfigured because of deviations.
One technical detail which, if not known or identified accurately, can result in problems with the installation or operation, is inrush current.
“Just the difference between 800 or 805 watts affects everything, and the more fixtures you have in your installation, the more it affects the design – how many circuits, how far away the fixture is from the panel,” says Pedersen.
While a difference of five watts may not seem like much, when you are installing 5,000 or 10,000 fixtures, this creates a significant deviation and introduces complications in a system. “This is why it is very important to have all of the electrical specifications reviewed ahead of time by an electrical engineer, or the electrical contractor completing the work,” says Evann Seney, Master Electrician, Honey Electric, Chatham, Ontario.
The first step is to ensure your electrical contractor has a detailed product specification sheet for each fixture, along with a complete application or installation guide, so that project engineers can properly design the system. Specification sheets should include: operating voltage range, full load current at common operating voltages, rated input power, power factor, total harmonic distortion, operating frequency, and inrush current on startup. Often, growers assume that engineers can assess wattage and other key factors simply based on name or by sight, which is not the case.
Knowing these details when the project is originally scoped ensures engineers specify and select the proper cables,
Put simply, the inrush current value informs the electrician about the instantaneous power demand from a light. Inrush current level has implications at the time of startup, in the event of power failure, and on the number of fixtures that can be switched on at the same time.
A fixture that has a very high inrush current can cause extensive issues in a lighting system, particularly if the circuits, cables, and transformers weren’t built to handle the load. A greenhouse system could have 100 to 200 lighting panels, all would have to be adapted – at significant expense – if the actual inrush current exceeds the provided specifications.
Certain LED fixture drivers will actively manage the fixture inrush current at startup. “All of our products are designed with
our own drivers,” says Chris Strom, Application Engineer for Signify, manufacturer of Phillips LED products. “One of the things designed into the drivers was a low inrush current. Many off-the-shelf drivers have a high inrush current, and that impacts the load on the lighting system.”
It is important to consider the effect that the inrush profile will have on system protection (such as circuit breakers and fuses). A circuit breaker sized properly for a fixture with a negligible or nominal load will trip the breaker at startup if fixtures with higher inrush current are installed.
The wrong inrush current between fixture and panel also means that each time power flickers throughout the electrical grid, the controls shut off those individual panels. That in turn, blows fuses. When the fixtures all come back at once, more issues occur.
“With our fixtures for example, we install a timer in every panel,” Seney says. “If the controls are shut off in the event of a power flicker, when the power comes back on, a timer in each panel is set to turn on one panel at a time.”
Wattage is a critical factor in LED lighting strategy design, and one that is taken only at surface value can quickly compound costs in a greenhouse. More specifically, experts say it’s important to pinpoint the optimal voltage operating range for your operation. “The specifications are going to show exactly what voltage range that fixture is good for,” Seney says. “You’re going to look for the full load current at each voltage.”
It’s a calculation that engineers and greenhouse electricians can make specifically and accurately, given they have the proper numbers and specs up front.
“Power or watts divided by voltage gives you current, or amps,” Seney explains. “However, you must also know the power factor of the fixtures to complete the calculation.” He adds, “Without proper specs, even a slight deviation in final numbers may require an installation redesign.”
In the same way, missing or incorrect information and specifications on fixtures could also lead to additional expenses. For example, an installation will be designed for a lighting fixture drawing 848 watts and the corresponding number of transformers. Strom commented: “Should a grower choose a cheaper fixture that draws higher wattage, say in this case, 855 watts, then additional transformers will be required, which will increase the cost of the project.”
The cost to accommodate the need for an additional transformer is multiplied by related costs including cables, concrete pads, and electric panels. “The installation costs more. It is a heavier cable. It adds more weight, and requires more supports in the structure to carry the weight of the load on the superstructure,” Seney says.
This is where the delicate balance of voltage, fixture placement and system design come to the forefront. “The efficiency and the wattage of the fixture, makes a big difference; whether you can put five or six lights on a circuit all depends on loading,” Seney explains. While you could technically load a circuit up to 80 per cent, it is not recommended because of the potential for additional unknown loading.
“We typically load less than the allowable Canadian standard, so there is flexibility,” Pedersen says. Factors to consider include the number of fixtures you can put on a circuit, the number of required circuits, the number and size of electrical panels,
the distance from the main service and transformers to the distribution panels, and whether cables can be installed overhead or underground.
If the electrician is given the correct information, the circuit and accessories can be sized correctly so that the right voltage drop can be calculated and properly accounted.
“Voltage drop and fixture efficiency are factors that determine the final cable size. How this plays out in the project design is that the fixtures at the walkway are typically closer to the panels. Whereas the fixtures at the gables are further away and require larger cables, which are more expensive,” Pedersen says.
Hand in hand with voltage comes the power factor – which represents how clean the power is. Experts know a certain amount of so-called “dirty power” comes in from any power grid. The most efficient and effective systems account for that dirty power up front, using voltage regulators and other tools.
The best fixtures account for 10 per cent coming in from the grid. For
example, if a lighting system is supposed to be running on 277 volts, and the power that comes in from the grid is just over 250 volts, the system will still run and function well.
“A power factor of 1.0 is perfect, and pretty much not achievable; 0.95 is still great. The closer the fixture is to a power factor of 1.0, the more efficient it is,” says Seney.
In British Columbia, where Pedersen operates, for grid connection they are mandated to BC Hydro, the power utility. “We’ve had it at multiple locations where the spec for the main service is 600 volt, three-phase, and from phase to neutral
is 347, so it’s a 600/347-volt service; however, the main power coming in is 590 or 580 volts,” he says. “BC Hydro won’t even talk to us until it’s less 10 per cent, so at that point we put in a transformer that’s tappable, or we use a fixture that can handle a little bit less power – plus or minus 10 per cent on the input power to the fixture.”
But a little-known and understood factor could potentially have the most impact, experts say. “It all comes down to the efficiency of the fixture, but also the main one for me, in our experience, is the harmonics,” says Pedersen. Total harmonic distortion (THD) indicates how much harmonic current is flowing in the power lines. Harmonics are unwanted currents at multiples of the fundamental line frequency. If there are huge spikes in harmonics from a fixture, this can result in damage to your upstream equipment,
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for example, high voltage transformers, lighting contactors, etc.
“If you have what we call dirty power, you have third and fifth and seventh harmonics, they are adding extra stress load onto the electrical installation, and that’s something that you have to account for. There have been a lot of people caught off guard by them,” says Pedersen. “That’s an extra load on the system, and if you’ve already loaded it to 80 per cent, and then you add a little bit more of a THD or extra resistance, your circuits overheat, and then the system fails.”
Complicating this is that often, the harmonics are not detectable with an ammeter, which is used to measure the current in a circuit. “You get a lot of extra neutral currents, and a lot of extra current on the system itself, and it measures fine,” Pedersen says. “We put a power meter on the circuit, and that’s where we see true loading of the electrical installation. The circuits are designed to open up a certain amount of power, and if you add more load to it, the circuits can’t handle it, and this is why circuit breakers are tripping, fuses are prematurely blowing, and contactors are failing. The harmonics of a fixture is a critical factor for these reasons.
In these situations, where high THD isn’t accounted for in the initial system design, it can be problematic. “I’ve seen THD cause all kinds of issues where electrical contractors have had to break up circuits and add additional circuits, and that affects the cost,” says Strom.
The experts emphasize that it’s critical for lighting suppliers to share complete and accurate product specifications especially on these key technical factors. For growers, their advice is to make sure contractors are aware of all of these factors, or if the project is in-house that their project team is planning around them. Rather than choosing fixtures purely based on price, they should evaluate these key factors to ensure they don’t have to retrofit or completely redo the electrical as a result of not planning for the right wattage, power factor or THD.
Otherwise, the project is at risk for serious scope creep.
“It can literally cause a domino effect,” says Pedersen, “putting us in a situation where we must go back and reconfigure the design and installation. Not surprisingly, the costs add up fast, and any anticipated savings of choosing a less expensive fixture are quickly lost.”
Joli A. Hohenstein is marketing specialist for Pen & Petal Inc.
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We don’t have to be reminded that we’re living in rather strange times. But then again, our parents and predecessors also had similar ‘strange time’ experiences at some point or another. But reports of greenhouses being left unused give an idea of the severity with which external circumstances are impacting our industry. “In a small corner of southeast England, vast glasshouses stand empty, the soaring cost of energy preventing their owner from using heat to grow cucumbers for the British market…. Elsewhere in the country, growers have also failed to plant peppers, aubergines [eggplant] and tomatoes after a surge in natural gas prices late last year was exacerbated by Russia’s invasion of Ukraine, making the crops economically unviable.”1
Similarly, here in Canada, historic high rates of inflation rate increases threaten the availability of goods right across the board. Perhaps not “the quintessentially British cucumber sandwich served at the Wimbledon tennis tournament and big London hotels,”1 but impactful nonetheless.
Back in the fall of 2000-2001, natural gas prices in B.C. went through the roof almost overnight. That winter, greenhouse producers talked much about alternative fuels, growing regimes and options for managing the fuel cost risk. Gas prices settled down, chatter of alternatives subsided and ‘things’
such change is not impossible, just difficult. I don’t have the answer in this short article. I am optimistic, however, that scientists and growers working on possible solutions do have the answer. Or at least part of the answer, and a combination of several partial answers may prove to be THE answer.
There appears to be more willingness to embrace change.
gradually grew back to normal. Whatever that is.
But perhaps this time around, things will be different. Technology for alternative energy sources has had two decades to develop. The foreseeable (if imposed) switch to all-electric or hybrid cars within the next decade or so demonstrates these advances. Whether one agrees with it or not, the last two decades have also brought about a much heightened awareness of, and activist-driven response to, issues of climate change. There appears to be a more significant willingness to embrace change.
But natural gas has been, and remains, such an elemental cornerstone of long-season greenhouse production that envisioning viable alternatives is difficult. The current advantages of gas mean it far-outweighs any potential competitor. Alternatives need redeeming features that are massively significant to persuade any switch. But remember, any
Perhaps we need NASA to help us out. During one of those sleepless nights that seem to be more common as I get older, I caught a piece on the NASA TV channel and was intrigued to hear about their “Game Changing Development (GCD) Program.”2 “The Program advances space technologies that may lead to entirely new approaches for the Agency’s future space missions and provide solutions to significant national needs. … (GCD) teams will be held accountable for ensuring that discoveries move rapidly from the laboratory to application. GCD’s efforts are focused on the mid Technology Readiness Level (TRL) range, generally taking technologies from initial lab concepts to a complete engineering development prototype. The Program employs a balanced approach of guided technology development efforts … from across academia, industry, NASA, and other government agencies. The Program’s investment in innovative space technologies supports NASA’s mission to “Drive advances in science, technology, and exploration to enhance knowledge, education, innovation, economic vitality, and stewardship of Earth.”2 Feeding the world and finding solutions to energy needs seem to fit this mission to me. Perhaps we need a ‘game-changing’ solution.
The article referenced earlier concludes on a stark note of pessimism: “Gas prices being so sky high, it’s a worrying time,” grower Tony Montalbano told Reuters, while standing in an empty glasshouse at Roydon in the Lea Valley [UK] where for 54 years, three generations of his family have farmed cucumbers. “All the years of us working hard to get to where we are, and then one year it could just all finish,” he said.1 Let’s hope for Tony’s sake, and all our sakes, that solutions come quickly.
1. HortiDaily, 1 April 2022.
2. NASA, GCD
Gary Jones sits on several industry committees in B.C. and welcomes comments at greenhousewolf@gmail.com.
