If you keep a greenhouse closed, you no longer lose precious heat, water, and CO₂. That's rather obvious. But if you want to keep the greenhouse climate optimal for the crops you grow, you will have to look for techniques that make this possible without having to open windows. A team of specialists affiliated with Gentle Green put their heads together to develop a system for this. And that system is ready to go to market, says Edwin van der Knaap.
Edwin van der Knaap, a cultivation expert with extensive international experience who filled the role of Chief Product Officer, recently joined the company. Gentle Green, based in Almere, developed an integrated climate system. The system gives the grower full control over temperature, humidity, CO₂, and air circulation at all times, thus providing the best conditions for crop production, says Edwin.
"The technology is a breakthrough technology. It assumes cultivation in a closed greenhouse. Our system provides very precise climate control, completely uniform throughout the greenhouse." Gentle Green is an engineering company that also takes care of the system's realization. The international team is composed of specialists with extensive experience in climate and process control in the built environment and process industry. "What we do is integrated system design, making use of existing technologies," he says.
The greenhouse can operate with fossil fuel but does not need fossil fuel. CO₂ is purchased or extracted from the atmosphere and serves as a supplement for plant uptake alone. Since the greenhouse is closed, the risk of entry of viruses, bacteria, fungi, and pollen is greatly reduced. Of course, this does not alter the fact that because of other carriers, such as seeds and humans, strict hygiene rules must be followed even in greenhouses with the Gentle Green system.
Test in greenhouse Almere
The system was used for the first time in 2021. In a greenhouse area in Almere, a section was converted to test the Gentle Green system. "The system works very precisely and with very low energy consumption," Edwin stresses. After extensive testing, a lot of time was put into value engineering (reducing costs) and making the system ready for production.
Currently, Gentle Green is in talks with growers of various crops. Edwin points to market developments that Gentle Green specialists say call for innovation in vegetable cultivation. "In the areas of CO₂, water, energy, and crop protection, among others, a lot is going to change in the Netherlands and many other countries in terms of legislation in the near future. With our system, growers are assured of a solution that is well ahead of this legislation and therefore future-proof."
During the development of the system, growers from several countries were involved. The cultivation expert sees opportunities in numerous crops, citing mainly vegetable crops initially. "We are working with tomatoes, lettuce, peppers, but also in medicinal cannabis. In addition, the system is also very useful for flowers and plants."
Storing heat
For that reason, Almere is certainly looking beyond the Netherlands. "If temperature or seasonal differences are very large, then the advantage of working with our system is even greater. Suppose as a grower you can only grow for 9 out of 12 months now because of summer heat, and with our system, you can grow for 12 months, you make interesting gains."
The closed greenhouse delivers the precision of a vertical farm without the high energy costs, as sunlight and solar heat provide PAR light and heating, Edwin explains. "Excess heat is removed and stored effectively and efficiently. With Gentle Green's system, the grower does not drain energy by opening windows when cooling, but can capture the thermal energy and use it elsewhere or store it for a later time."
New building
The most striking thing about the outside of a greenhouse with the Gentle Green system is the fact that there is little or no need for open windows. "In addition, inside the greenhouse, you will see that we are working with different technical features than in a regular Venlo greenhouse," he says.
With the system, the young company is betting on both new-build projects and retrofits. The latter has been applied at the pilot site in Almere. The system has also been patented. "With the start-up of the international projects, a whole new phase is beginning," he says.
Edwin van der Knaap and investor Anton Klunder
For more information:
Edwin van der Knaap
Gentle Green
evdknaap@gentlegreen.nl
www.gentlegreen.nl