Cultivating sustainable growth in the greenhouse industry

Article by Torben Poulsen, Business Development Manager,
Drives and Pumps, ABB Motion

With several advantages over traditional farming methods, greenhouse farming is a fast-growing trend in agriculture. The proof is in the figures, with recent research by Precedence indicating that the global commercial greenhouse market is set to grow to $78.9 billion by 2030 from $34.8 billion in 2021.

Two factors are central to this growth in popularity. First, greenhouses eliminate climate uncertainty to ensure year-round production in closely controlled growing conditions. Second, and perhaps the most significant, is that rapid urbanization means less open space to for farming. Conversely, greenhouse production makes it possible to produce fruit and vegetables in urban areas much closer to the point of consumption.

The challenge for commercial greenhouse operators is that they are typically equipped with large and complex crop management systems. To function harmoniously, they require reliable and consistent processes.  Just one parameter operating outside the set limits could compromise the balance of the entire system.

The irrigation of greenhouse crops is one of the most crucial production practices. Yet it’s also energy-intensive, with electric motors driving various pumps, sprinklers, and other equipment. The continuing rise of energy costs, combined with energy shortages in certain parts of the world, requires close attention to optimizing energy efficiency. Careful monitoring and control of water consumption are also vital since water is becoming a scarce resource. 

The good news is that recent developments in variable speed drives (VSDs), motors, and programmable logic controllers (PLCs) make it possible for greenhouse operators to increase their equipment’s energy efficiency and productivity simultaneously.  

Greater accuracy to boost performance  

Optimizing all critical processes is central to the successful operation of a greenhouse. One such process is drip irrigation, which provides greater control over the amount of water applied. Regulating the water flow and pressure is a critical element of this, but it can be challenging.

Pressure surges can lead to water hammer – shockwaves propagating through a piping system when a fluid in motion is forced to stop abruptly or change direction. This strains the pipework, especially at weak points such as joints, and can damage the pipes, valves, and sprinkler heads. The mechanical stress ultimately shortens their lifespans and results in leakage. For example, a sprinkler head can pop off completely if the pressure is too high and may need replacing. Burst pipes can cause flooding, but even minor, invisible leaks can add to substantial water loss, impacting energy efficiency and operational costs.

Controlling electric pump motors with drives can address these issues by regulating the water pressure to match the actual demand. Built-in algorithms will reduce the possibility of water hammer and cavitation, while low-pressure detection will indicate leakage. Programmable logic controllers (PLCs), which excel at streamlining repetitive processes, can automate the whole process and are well-suited for drip irrigation.

Water demand in a greenhouse varies. It’s usually high during the peak growing season while dropping off during other periods. Drives make variable pumping possible so the system can adjust to changing demand, optimizing water resources.  

In addition, drives are capable of intelligent pump control (IPC). This feature enables them to control the pump motors’ speed according to demand without the need for an external controller. 

Driving efficiency

Motor-driven pumps, lighting systems to support crop growth, and ventilation systems used for environment control are the three primary sources of electrical energy consumption in greenhouses.  

A motor not controlled by a drive constantly runs at full speed, with operators adjusting the output manually via throttling. Conversely, a drive adjusts the speed and torque of the motor to meet the exact requirements of the process. Due to the relationship between speed and energy consumption, a relatively small reduction in speed will yield significant energy efficiency improvements. For example, a pump running at half speed consumes only one-eighth of the power. 

This means pairing a drive with a motor will typically reduce energy consumption by around 25 percent or more.  Furthermore, given fluctuating energy prices, it is possible to recover the installation cost of the drives within a few months. 

Greenhouse systems will also benefit by upgrading their motors to a higher energy efficiency class.  The current minimum requirement for all new motors installed within the EU is IE3, although many existing industrial motors are still rated lower.  

However, ultra-efficient IE5-rated synchronous reluctance (SynRM) motors can reduce energy losses by up to 40 percent compared to IE3 models. Greenhouse operators don’t just stand to save on operating costs – high-efficiency motors and drives will also reduce their carbon footprint.

Better control and safety

Drives offer flexible functionality and a high level of controllability. This includes soft starting and stopping, which decreases stress and friction on motors and other mechanical parts. Another important safety feature of advanced drives is safe torque off (STO). 

STO stops the motor in a controlled way and inhibits the drive from restarting until a reset is activated. Enhanced safety is particularly useful during inspection and maintenance.

Data for informed decisions 

Improvements in advanced drives include built-in sensors that monitor performance and energy usage during operation. Sensors can also be fitted to various equipment, such as motors and pumps, to collect performance and condition data. The sensors deliver the data to the cloud, which is stored and analyzed, enabling informed decision-making for planned maintenance. This increases productivity by maximizing uptime while operators can adjust operating parameters for improved energy efficiency. 

Sustainable growth 

An increasingly urbanized world makes greenhouse farming an ideal agricultural solution,  but operators face significant challenges in  energy consumption, cost efficiency, and overall productivity.

Adopting the latest data-driven drive and motor technology offer substantial efficiency gains that can help greenhouses feed growing cities more sustainably. 

For further information, please visit: https://new.abb.com/drives/segments/food-and-beverage/agriculture 

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