Research results by WUR and Svensson introduced at Greensys2017

The Greensys2017 was held on August 20-24th in Beijing, China. The event was a big success as 500 researchers from 30 different countries including China, the Netherlands, the United States, Japan, and Israel amongst others joined together in discussion. The main symposium topics focused on greenhouse climate control, crop management, light control technology, plant factories and horticulture product quality which provided both a well-rounded educational and communicative platform for the industry.

Svensson has been closely working with Wageningen University and Research Center (WUR) to conduct extensive greenhouse climate screening research. During the Greensys2017 event, the research findings were presented and explained in detail using theoretical models and supportive data, with the goal to provide a better understanding of the role that climate screens have on greenhouse climate control and how screening can potentially impact energy savings.



Leo Marcelis, Professor at WUR explained that a stable environment is very important to plant growth and pointed out that during the day, the natural light intensity levels will fluctuate, but can be more stable and better controlled when a diffuse greenhouse climate screen is installed. As research shows, more stable lighting conditions will increase the photosynthesis rate much more compared to fluctuating and uncontrolled lighting conditions. Svensson's light diffusing Harmony screen range spreads light uniformly throughout the greenhouse and allows light to penetrate deeper into the canopy, improving the overall crop quality and production.

In regions like the Netherlands, where maximizing light is a critical driving force in horticulture production, researchers continue to focus on finding new methods that increase the efficiency of light use in the greenhouse. During the event, WUR's Frank Kempkes explained how to increase light transmission in venlo greenhouses by 10% during winter months. To achieve this, he suggests the use of the highly transparent covers; improving the roof slope and orientation; cleaning the roof more often; and using reflective greenhouse construction parts. To further support his findings, Svensson developed a special highly transparent prototype energy saving screen that was installed using an innovative installation method. Kempkes findings provided excellent insight to growers, greenhouse builders and installers.



With so many different screening types to select from today, all with different energy savings, the need for a standardized method to quantify the energy savings performance of greenhouse climate screens from different suppliers has become more important than ever. Dr. Silke Hemming from WUR talked about recent research she conducted on the radiation, air permeability and moisture transport of different screen materials. These factors significantly influence the screen's energy savings potential. Dr. Hemming also elaborated on what should be considered when evaluating energy savings, including the average percentage of energy savings on a yearly basis, the average energy savings percentage during night hours, and the maximum energy savings during the highest gas usage periods at night.



Feije de Zwart concluded the event by introducing a new online model, called the "Radiation Monitor" which was developed by WUR and Svensson not long ago, to show how greenhouse screens influence the climate. The physical properties of Svensson screens can be added into the model, showing how the screen can influence plant temperatures in the greenhouse. Overall, the online model has proved to be a very beneficial educational tool.