How to Save Greenhouse Energy

Greenhouse growing is an important part of food production. They let growers grow more crops per plot of land, grow higher quality produce, and grow fruit and vegetables off-season.

However, growing in greenhouses, especially modern, technological greenhouses, requires a lot of energy. With energy prices rising, and uncertainty surrounding the energy market, it’s important to be able to reduce greenhouse energy consumption. So, how can you save greenhouse energy?

Why Is It Important to Save Greenhouse Energy?

Before we dive into how to save greenhouse energy, it’s important to understand why it’s crucial to do so.

We take commercial greenhouses for granted. But the fact that growers can invest in greenhouse structures, equipment, and the energy needed to run everything, relies on it being a profitable business. If growing food were to become unprofitable, growers would stop doing it.

Maintaining Growers’ Profitability

Growing food, and other crops, provides a livelihood for entire communities. This livelihood is dependent on energy prices, which have a huge impact on growers’ ability to turn a profit.

Rising energy prices pose a serious problem for growers on all levels. In many places growers have already halted production, as their business has become unprofitable due to high energy costs.

Food Security

One of the biggest issues this raises is food security. One of the biggest issues this raises is food security. Growing locally is one of the best ways to ensure access to food for the population of a country or region.

Relying on external food sources is fine to an extent. But in case of shortages, economic crises, or war, many nations may find themselves struggling to secure produce. This is a major incentive for many countries to protect their horticulture sectors. Many governments offer grants or subsidies for energy saving technologies for greenhouses, to protect their food supply.

5 Ways to Save Greenhouse Energy

Fortunately, improving energy efficiency and reducing the energy requirements of greenhouse operation is entirely possible.

There are numerous things greenhouse operators can do keep growing, at a much lower energy cost.

1. Keep the Greenhouse Closed and Improve Insulation

One of the biggest energy expenses in greenhouses is heating and/or cooling. Much of this is due to heat loss associated with ventilation or poor insulation.

There are two parts to retaining heat inside the greenhouse. First, is to operate in a closed greenhouse, avoiding ventilation at times when it’s inefficient. Using energy conserving equipment such as thermal screens can further increase the ability to retain heat inside.

Keeping the greenhouse closed may lead to problems such as high humidity. However, you can solve this issue using efficient dehumidification. We’ll expand more on this topic in the following tips.

The second part to retaining heat is to improve insulation. The first thing you can do is fix any leaks in the greenhouse cover. Additional ways to improve greenhouse insulation include weatherstrip doors, vents, and fan openings, as well as aluminum faced building paper and insulation boards.

2. Use High Efficiency Lighting

Many greenhouses use grow lights to lengthen the duration of the day, or to supplement during cloudy and rainy days. The type of lights you use can have a big impact on the amount of energy your greenhouse requires.

Switching to efficient grow lights, such as LED lights, can save as much as 40% on energy, compared to CFL lights. This figure can go as high as 90% when comparing to incandescent bulbs.

3. Utilize Efficient Environmental Controls

Using efficient equipment to control your environment is one of the most important ways to save energy in the greenhouse. In this section, we’ll cover two aspects of climate control – heating/cooling and humidity control.

3.1 Use an Efficient Heating System

Most modern greenhouses use heating or cooling systems to control their temperature and provide ideal conditions for the crops.

There are many different types of heating systems, relying on various technologies and energy sources. As every greenhouse is different, there isn’t just one efficient heating solution. For example, some greenhouses may have access to hot water, in which case using heating pipes may be most efficient. Others may HVAC systems to provide the most comprehensive solution for both heating and cooling.

Therefore, comparing the efficiency of different systems and finding the right solution for your situation, is the most important factor.

3.2 Use Effective and Efficient Dehumidification

Growing crops in a closed greenhouse will inevitably lead to high humidity. In fact, humidity is one of the main reasons growers open the greenhouse in the first place.

However, dehumidification technology has become extremely efficient in recent years. DryGair’s DG-12, for example, removes ~45 liters of water from the air, per hour, running on only 10 kW. That’s an efficiency rate of ~4.5 liters (1.2 gallons) per kWh.

Being able to control humidity effectively, without much energy, makes ventilation highly inefficient. Rather than releasing air to deal with humidity, growers can keep the greenhouse closed, creating ideal relative humidity levels from inside.

Using dehumidifiers this way can save an average of 50% on overall greenhouse energy costs. That makes dehumidifiers one of the most effective ways to save greenhouse energy.

4. Incorporate Real-Time Monitoring

Controlling the greenhouse climate can get complicated. Without being sure what the conditions truly are, climate control becomes more of a guessing game.

Of course, if you’re unsure about the conditions in your greenhouse, you won’t be able to optimize your environmental control protocols. This way, growers end up overheating, overrunning dehumidifiers, etc.

Real-time monitoring lets you know exactly what’s going on, allowing you to react appropriately and with precision. So, you can apply the controls you need, without risking it being insufficient, or investing more energy than necessary as overcompensation.

5. Don’t Neglect Maintenance

One way to ensure everything is running efficiently, is to run routine maintenance checks on greenhouse equipment and machinery. Proper maintenance should cover everything mentioned above, to ensure that things are running smoothly.

To maintain your greenhouse efficiency, and save on energy, you should check boilers, air conditioning systems, dehumidifiers, and vents annually.

It’s also a good idea to check for leaks in your insulation, to ensure your greenhouse retains heat as efficiently as possible.

Maintenance is the glue that holds your greenhouse efficiency together. Neglecting to take care of machinery and equipment will lead to a decline in efficiency, ultimately increasing energy consumption.

DryGair manufactures the leading dehumidifiers for commercial horticulture, providing energy savings of 50%, on average, in greenhouse cultivation. Please feel free to contact us for more information.