Growing top quality plants is the ultimate goal of every greenhouse farmer.
But especially for commercial greenhouse operations, the greater challenge in this narrow-margin, competitive business is how to consistently grow and maintain financial success. One of the greatest impediments to that is figuring out how to keep your energy expenses down.
In this article, we’re going to look at ways you can reduce greenhouse energy costs and possibly even eliminate them entirely. First, let’s get the whole picture on greenhouse energy consumption and the other costs of running this specialized farming business.
The costs of greenhouse farming
While the sunlight needed to grow plants is free, there are many other parts of the greenhouse business process that are not, such as:
- Electricity
- Climate control (heaters, ventilation, sensors, & monitoring equipment)
- Lighting systems
- Water, soil, & nutrients
- Humidification
- Building materials and maintenance
- Marketing
- Packaging and distribution
And those are just the basics.
Like many businesses, the key to sustainably improving margins lies in reducing production costs and energy consumption. With today’s technology, you can do both.
Greenhouse energy consumption
Greenhouse farm production has increased by a factor of six just in the last 20 years, and the energy demand required to maintain it is growing just as rapidly.
According to the Canadian National Energy Board, the annual CPI (consumer price index) of energy has risen by 52 percent from 2012, while the general (average of all goods) CPI has only grown by 30 percent. In other words, energy costs are outpacing the revenue you can earn by selling the products from your greenhouses.
As one example, the amount of grow-room electricity just for the booming commercial cannabis and hemp industry is now estimated at 1% of all electricity consumed in the US.
Commercial greenhouses generate this power in a variety of ways, such as natural gas, heating oil, conventional electricity, and other systems. Some are even using renewable energy systems such as solar power.
Energy efficiency measures — using less to grow more
With costs and usage climbing each year, especially in winter, greenhouse growers should be looking to reduce energy consumption, in addition to seeking out alternative fuel sources.
Here are some ways to reduce costs and aim for peak efficiency:
Keep out the cold
“Leaky” greenhouses, with cracks, holes, air leaks, and openings in the walls or roof, allow warmed air to escape. This requires the heating system to run longer and more often to maintain the required temperatures.
This negligence in maintenance can cost growers hundreds, or even thousands, in unnecessary heating costs every year, as well as placing additional wear and tear on heating equipment.
You can reduce air leaks by regularly inspecting your greenhouses. With a little spray foam and caulk, you can stop these leaks in your grow rooms (and bank accounts) and can often reduce heating bills by up to 10%. Greenhouse integrity keeps the heat inside and helps maintain humidity levels and a consistent air temperature, which improve growth production.
Use a dehumidifier
Wait, wouldn’t this increase energy consumption if you’re not using one now?
That depends on how you’re currently dealing with humidity. Many greenhouse operations use ventilation, such as a partially open louver, to expel the air when humidity builds up too high, replacing it with drier air from outside. But if you’re doing this in cold or hot weather, this means you now also have to heat up or cool down the new air you just cycled in.
All the energy your heating and cooling systems will be using to lower temperatures in the summer or raise them in the winter would be saved if you could just dehumidify the interior.
Insulation and thermal blankets
The northern wall of a greenhouse typically receives very little light, since we’re in the northern hemisphere.
Winter sun and cooler temperatures
This is especially true during the winter when the sun is lower in the sky. This not only makes it more difficult to maintain an even temperature from one side of the room to another but increases heating costs in compensating for the constant loss of heat through that wall.
Insulating the north wall of your greenhouse can significantly reduce heat loss and improve energy efficiency.
Many greenhouse growers use white insulation boards, aluminum foil, or other materials which, in addition to helping protect the wall from cold, can also reflect the southern sunlight back into the room instead of allowing it to pass through the north wall. This creative capturing of light transmission reduces your need for additional heat generation.
Summer heat and warmer temperatures
Even during the warmer months, as much as 85% of heat loss occurs at night.
A thermal blanket or curtain helps hold in the warmth of the day, reducing energy consumption during the darker hours. Thermal blankets can be a cost-efficient investment, are easy to install, and can be rolled up each morning to maximize daylight.
Heat retention blankets can reduce energy costs by up to 50%, and typically pay for themselves in just one or two years. In hot climates, you can also use blackout screens to keep excess sunlight from overheating your greenhouse.
Generate your own energy
All these ideas are great.
But the best return on your efforts to cut costs is to pull the plug on nonstop energy cost increases from the electric company and seek out cheaper and cleaner alternative energy sources.
The largest greenhouse energy cost for most businesses is the cost of maintaining growing temperatures during the colder months of the year.
With the rising prices of power-plant electricity, as well as other consumable fuels, more and more nursery and greenhouse growers are converting to solar powered gardens and using renewable energy to reduce both their expenses and their carbon footprint.
Using the sun to power your greenhouse is unique in that it can significantly reduce operating costs without reducing the amount of energy you’re using. In fact, depending on the size of your operation and the amount of solar power you can generate, you may even find yourself selling power back to the power company!
Solar panels may be less costly than you think
The biggest hesitation, historically, for converting to a solar-powered business model has been the initial installation costs. But prices have fallen significantly in recent years, and many growers will qualify for special financing as well as tax credits and grants that could pay for the majority of the system.
It’s worth your time to see if solar energy makes sense for your greenhouse farm.
Solar power facts
There are reasons that more than one hundred Fortune 500 companies have begun using clean, renewable solar power options, and that more are joining the ranks every day.
- It takes the average business 4 – 6 years to cover the initial installation cost.
Because greenhouses tend to use more energy, that means it takes less time to reach the “break-even” point.
- The average commercial property owner can reduce overall energy costs by 75 percent by going solar, potentially reducing a $1,950 monthly electric bill to just around $500 after converting to solar power.
Energy efficiency is a great way to reduce your operating costs and maintain profitability of your operation. But producing and owning your own power bypasses the whole electricity generation process, and saves piles of money in the long run.
Keep in mind that not every one of the measures described here will be appropriate for every situation. Sometimes an energy conservation measure is simply too expensive to install, relative to the expected savings. However, it’s a good chance that some of the suggestions above will help make your greenhouse more energy-efficient and cost-effective in the coming years.
Combat rising energy costs with solar
Contact the pros at Ag Solar Solutions for a free energy analysis. We’ll visit your operation in-person and detail ways to reduce your energy consumption and provide a cost/benefit estimate for your own in-house energy production.
Stop worrying about energy waste and growing fuel costs and get back to growing your plants and increasing profits.
