The business world, agriculture and floriculture included, is implementing increasing numbers of sustainable practices up and down the supply chain. Sometimes companies are pushed by regulatory pressures and at other times are lured by financial incentives, such as carbon credits. A third reason — not to be discounted — is a belief in doing the right thing for the environment and community — and the operation. Sustainability initiatives are good for business because they also can save money and increase profits.
There’s a plethora of definitions of sustainability, but this one is succinct: Sustainability is doing everything possible to reduce your impact on the environment around you while retaining your profitability. Equipment that conserves water, energy, material and labor, and reduces waste, often pays for itself in just a few years. In some cases, growers may not need to pay for it in the first place. State and federal grants are often available for these types of projects.
Ways to Save in Greenhouse Operations
Tips for saving energy abound, and many action items don’t require new equipment. However, upgrades in boilers, fans, greenhouse coverings and lighting can save significant dollars while also benefiting the environment. Consider some of these equipment upgrades and how they can save you money:
Many factors influence the choice of glazing material, including cost, durability and light transmission. Heat retention is a prime consideration in areas with cold winter temperatures.
Energy Curtains. Installing energy curtains is one of the easiest ways to save heat. Also called shade curtains or thermal curtains, growers can reap savings of 20% to 50%, with a payback in one to two years. Pulling energy curtains across a crop at night prevents heat from rising high up into the roof and keeps it down at plant level where it’s needed.
Greenhouse coverings. While many factors influence the choice of glazing material including cost, durability and light transmission, heat retention is a prime consideration in areas with cold winter temperatures. For example, the R-value, or measure of resistance to heat loss, of 3 mm single-pane glass is 0.95, while the R-value of 10 mm twinwall polycarbonate is 1.79, meaning the latter is nearly twice as efficient and will dramatically reduce heating costs.
Floor- or under-bench hydronic heat. Keeping heat near the plants is better for the crop and for your energy bill. Doing this can allow the air temperature to be set 5 to 10 degrees lower. Under-bench hydronic heat in particular creates a more uniform root-zone temperature than a system that heats air above the plants. This results in better germination and rooting of young plants, and faster root and plant growth overall.
High-efficiency fans. Using fans that have a ventilation efficiency ratio greater than 15 can pay off in energy savings. With fans, you generally get what you pay for, so spending more and upgrading to a high-efficiency model will save you money in the long run. Variable frequency drives can automatically adjust the fan speed based on the temperature.
LED lighting. Replacing high-pressure sodium lights with LEDs can save 35% to 55% in electricity costs. Since lighting is usually one of the largest components of the electric bill, savings can add up quickly. Consider adding automated control systems that can optimize light levels based on crop needs and the amount of available sunlight.
Energy curtains, also called shade curtains, can save 20% to 50% on heating costs.
Auxiliary Power Units. Save big on diesel costs by installing auxiliary power (APU) units. When a truck is in park, the APU unit becomes the main source of power for keeping the engine warm, providing heat or air conditioning, or charging the battery. Diesel consumption while a truck is idling is approximately one gallon per hour when running air conditioning or heat. When an APU takes over, consumption is reduced to 0.1 to 0.5 gallons per hour under the same conditions—a reduction of 50% to 90%. Many states have idling regulations, and APUs can help meet those requirements.
Drip irrigation and subirrigation. Both drip and sub-irrigation systems can drastically reduce water waste. With drip irrigation, 100% of the water and nutrients are delivered to the plant, so nothing is wasted. With sub-irrigation, water use can be reduced by up to 50% and fertilizer use by 25% to 50%. Additionally, water used in sub-irrigation can be collected, stored and reused. If you pay a water bill or live in an area where water use is a concern, installing these systems can provide significant savings. Flood floors, ebb and flood benches, trough systems and capillary mats are all types of subirrigation.
Retention ponds. Consider building a retention pond to collect and reuse water. Pumps and filtration equipment will also be necessary, but grant money may be available.
Watering basket boom system. Using this type of system for hanging baskets can save water, fertilizer and labor. The baskets go around a carousel, and rather than watering every basket whether it needs it or not, the boom system weighs the basket and only waters if it is lighter than the set threshold. Water and fertilizer are only dispersed if a basket below a certain weight is present. The system also reduces the need to continually condense baskets on the line.
Funding Your Investment in Sustainability
Fortunately, many funding options are available for energy and water conservation equipment through both state and federal sources. One of the best-known grant and loan programs is REAP, the Renewable Energy Systems and Energy Efficiency Improvements Program. Others are also available; visit grants.gov for more detailed information on national programs. In addition, check with your state department of agriculture to see if they are offering funding or incentives.
Keeping the heat at the root zone, such as with the Heat2O Hydronic Heat system shown here, allows the air temperature to be set lower and provides better uniformity of rooting.
“There are a lot of options available to growers,” says Will Bean, owner of Evergreen Equipment Finance in Puyallup, WA. “The nursery industry is an attractive industry for underwriters. Historically it has been stable, and certain underwriters actively look to invest in greenhouses and nursery equipment. Everything from grants, small business administration (SBA) loans and traditional bank financing is available.”
Bean says the loan underwriters he works with specialize in working with agricultural businesses and have a good understanding of the industry. For instance, while some banks might require land as collateral on a loan, these companies may be fine with accepting the greenhouse structure as collateral, knowing many growers lease their land. When growers approach Bean for financing water or energy-saving equipment, he always directs them first to their state department of agriculture website or to federal programs at grants.gov. If they still need financing, he says it’s a simple procedure.
“We talk about the project, what they want to finance and what terms they would like,” he says. “If we are just financing the greenhouse, we’ll typically set up an approval for three- to seven-year financing. If it includes a new parking lot, greenhouse and other upgrades, we’ll look at a 10- or 15-year SBA loan.”
Most transactions only require a one-page credit application, Bean says. Approvals for three-to-seven-year financing typically take about one day, while the SBA program takes about five business days.
Bean emphasizes he can only make loans for capital purchases such as equipment and structures, not consumable materials. “Sometimes I have a customer call me up and tell me he just purchased a greenhouse and now he needs to borrow money for the fertilizer and soil media. And he’s in trouble because he used operations money to purchase equipment.”
The main challenge for borrowers is understanding the importance of personal credit scores, Bean says. The best underwriters look for credit scores of 700 or higher, which allows them to offer the best rates. The most common reason for a loan not to be approved is the credit score.
“We can do loans to new businesses, but if the borrower has a credit score of 650 or less, it’s difficult to get money. At a minimum, it will be at a penalty of a higher interest rate.”
Bean says if an equipment upgrade is going to save significant money in just a few years, don’t feel you have to wait until you can pay for it in total: “If financing can allow you to start saving money right away and the interest rate and other terms make sense numbers-wise, it’s smart to invest in better equipment or structures. It’s a smart decision for your business and can provide environmental benefits as well.”
Ask the experts at Stuppy about upgrades that will make your operation more sustainable — and profitable.
Bartok Jr., John W. 2019. The Advantages of Subirrigation. Greenhouse Management. https://www.greenhousemag.com/article/tech-solutions-advantages-subirrigation/
Bartok Jr., John W. 2005. Checklist: Energy Conservation. UMass Extension Greenhouse Crops and Floriculture Program. https://ag.umass.edu/greenhouse-floriculture/fact-sheets/greenhouse-energy-conservation-checklist
Ciokosz, Daniel. 2023. Things a Greenhouse Grower Can Do to Improve Energy Efficiency. PennState Extension. https://extension.psu.edu/things-a-greenhouse-grower-can-do-to-improve-energy-efficiency
Diesel APUs. North American Council for Freight Efficiency. http://truckingefficiency.org/
Energy-Saving Greenhouse Technology You Should Know About. Save On Energy: Power What’s Next. https://saveonenergy.ca/For-Business-and-Industry/Resources/Energy-saving-greenhouse-tech