Getting smarter

Sustainable Strawberry Project where Cravo’s retractable roof greenhouses are used to create a superior growing environment for strawberries.

Sustainable Strawberry Project where Cravo’s retractable roof greenhouses are used to create a superior growing environment for strawberries.

By 2020, the value of the worldwide smart greenhouse market is expected to reach more than USD 1.2 billion, as increasingly, greenhouse growers turn to new advances in technology for better and faster crop yields. By CHRISTINE BROWN-PAUL

Greenhouses allow for growing plants in a controlled environment, capturing incoming visible solar radiation and retaining heat to provide a favourable environment for plant growth. Traditionally, the majority of greenhouses have used soil as the base for growing plants, however, hydroponic horticulture is now a dominant force in the greenhouse industry. In a bid to save labour and to achieve superior yields in a faster time, many growers are turning to implementing smart greenhouse technology. Worldwide, it is expected that by 2020, the smart greenhouse market will be worth more than USD1.2 billion.

A smart greenhouse is defined as a type of urban farming where crops are cultivated without human intervention. Across the globe, smart greenhouses have a strong presence, with Europe an early adopter and holding a major market share. However, developing regions such as Asia-Pacific (APAC) are also witnessing impressive growth in the market while the Middle East is the largest-growing country in the Rest of World (RoW) region in the smart greenhouse market. Increasing urbanisation and development is a contributing factor behind the growing demand for urban farming in these regions.

The smart greenhouse market, based on technology, is broadly segmented into heating, ventilation and air conditioning (HVAC), LED grow lights, communication technologies, irrigation systems, material handling, valves and pumps, control systems, and other areas.

Some of the major players in the smart greenhouse market include: GreenTech Agro, LLC (US), Nexus Corporation (US), Certhon (Netherlands), Logiqs B.V. (Netherlands), Hort Americas (US), Argus Control System Ltd (Canada), LumiGrow Inc. (US), Terrasphere Systems, LLC (US), and Rough Brothers, Inc. (US) and Swedish company, Heliospectra AB.

Medium and high technology greenhouses make use of a range of sensors, which link into automated control systems.

Medium and high technology greenhouses make use of a range of sensors, which link into automated control systems.

HVAC
HVAC is the technology used for maintaining optimum temperature within a controlled environment. In the case of greenhouses, HVAC plays a vital role in maintaining an ideal temperature for plant growth and is needed to nullify the effects of external temperature changes and enable cultivation throughout the year. HVAC systems are designed to take into consideration the external and internal environment fluctuations in the region in which the greenhouses are established.

According to industry experts, the heating requirements of a greenhouse depend on the desired temperature for the plants grown, the location and construction of the greenhouse, and the total outside exposed area of the structure. Much of the daily heat requirement may come from the sun, but if growers require their greenhouses to be more than a few degrees above the outside temperature at night, they will need to provide it with a heat source. The heating system must be adequate to maintain the desired day or night temperature. Heating systems can be fuelled by electricity, gas, oil, or wood. The choice of a heating system and fuel depends on what is locally available, the production requirements of the plants, cost, and individual choice.

Ventilation is the single most important requirement for a greenhouse, with two important purposes: providing fresh air, mainly carbon dioxide, to plants and cooling for the greenhouse. Without good ventilation, a greenhouse is nothing more than a solar furnace. Greenhouses are really designed to store heat from the sun during the day creating a warmer temperature in the greenhouse versus outside of it. This makes cooling a greenhouse on a hot day a difficult task that cannot be accomplished without a good ventilation system. Cooling in the summer can be accomplished most easily with a combination of shade, proper ventilation, and an evaporative cooling system like a misting system, fogger, or evaporative cooler.

In the past few years, there have been many technological advances in indoor garden heat management, all of which can affect the sizing and set-up of ventilation systems. Air or water cooled reflectors have the potential to effectively reduce heat in the greenhouse, minimising the required size of any exhaust fan.

Many growers are now using sophisticated techniques, combining air or water-cooled reflectors, dehumidifiers and highly efficient mini-split ventless air conditioning units. When used in conjunction, these technologies reduce heat to a minimum and—as long as CO2 is being supplemented—make exhaust fans unnecessary.

Heliospectra’s LX60 Series LED system is Wi-Fi enabled, allowing for online monitoring, scheduling and control.

Heliospectra’s LX60 Series LED system is Wi-Fi enabled, allowing for online monitoring, scheduling and control.

LED grow lights
When it was first developed, LED grow light technology was costly compared to other technologies and this led to its usage being restricted in terms of applications where urban farming is conducted on a large scale. However, with advancements in technologies and awareness about energy efficiency compared to other lighting technologies, its adoption has increased rapidly. Globally, this market is expected to grow at a Compound Annual Growth Rate (CAGR) of 27.46% from 2015 to 2020.

LED grow light technology holds the largest share in the overall smart greenhouse technology market. The need for energy-efficient light and long-lasting technology is one of the main reasons for its high growth in this market. LEDs have a long life of 50,000 hours, while incandescent lamps can work for only 2000 hours. They can last for nearly eight to 10 years, assuming 14 to 18 hours of daily use. Also, LEDs consume 50% and 85% less electricity than fluorescent lamps and incandescent lights, respectively.

Recent developments in LED technology create new opportunities for low- and high-intensity lighting of greenhouse crops. Light-emitting diodes have a variety of advantages over traditional forms of horticultural lighting. Their small size, durability, long lifetime, cool emitting temperature, and the option to select specific wavelengths for a targeted plant response make LEDs more suitable for plant-based uses than many other light sources.

A world leader in lighting technologies for plant research and greenhouse cultivation, Heliospectra was recently recognised in two new AgTech research reports, Smart Greenhouse Market—Forecast to 2020 and LED Grow Light Market—Forecast to 2020 for its innovation in LED lighting technology for greenhouses.

Heliospectra technology combines sensors—which monitor the condition of plants and how they use the light—with state-of-the-art software that controls the lighting.

Heliospectra’s premier product is its patented, energy-efficient LX60 Series LED system, arguably the most sophisticated, modular LED lamp available for commercial and R&D grow operations worldwide. The LX60 is Wi-Fi enabled, allowing for online monitoring, scheduling and control. Among other features, external sensors and software can be added to the system.

Sundrop Farms uses concentrated solar-thermal technology to desalinate seawater for growing tomatoes in its greenhouses.

Sundrop Farms uses concentrated solar-thermal technology to desalinate seawater for growing tomatoes in its greenhouses.

Solar is the future
The concept of the smart greenhouse also embraces smart thinking, especially in terms of strategies designed to lower energy consumption. As energy prices rise and the economy slows down, it is no surprise that many greenhouse growers are wondering how they will survive. Across the world, more growers are becoming more energy efficient and using alternative energy sources such as solar and wind energy to power their greenhouses.

In South Australia, Sundrop Farms uses solar-thermal energy to desalinate water from the Spencer Gulf to grow tomatoes in greenhouses, the only operation of its kind in Australia. Set for completion in 2016, the greenhouse will be powered by concentrated solar-thermal technology (not solar PV panels). The company already has a pilot site set up, which will now be used as a training facility.

“What we want to do is try and simulate the activities that will go on at the commercial greenhouse, such as maintaining the crop and harvesting,” said Sundrop’s Australian managing director John Phinney.

“But if we were to do all of those activities over and over again on a live crop, it could potentially be damaging.

“We have a few dummies set up using bamboo and string and a bit of ingenuity, so it’s really exciting to see something that from my perspective is really indicative of how creative and motivated our team here is,” he said.

“We understand that a vast majority of the people that will be coming in, it may be their first time working in horticulture and probably almost certainly working in a greenhouse, so it will be a learning process for them.

“But we are really excited about the opportunity. We have to basically start a new industry here and we are excited for members of this community to come on the journey with us,” Mr Phinney said.

It is expected that the facility will save 700 million litres of freshwater and 14,000 tonnes of CO2 equivalent a year.

Read the full article in October 2015 / Issue 160. Ω


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