TNO is working towards remotely monitoring greenhouse performance. Within the Hortivation Foundation, the first two greenhouse growers are gaining experience with Kas Prestatie Monitoring (Greenhouse Performance Monitoring). There are plenty of sensors that generate data on the climate or control, but sensors in greenhouse structures are not there yet. Reason for TNO to investigate, on its own initiative, whether this is possible.
TNO already has a lot of experience with this technique. For several years now, well-known steel bridges like the Van Brienenoord Bridge have been equipped with sensors. These readings are linked to a computer model of the bridge. This allows defects to be detected at an early stage. The bridge's residual life and safety can also be determined at any time.
"Using sensors in the metal profiles of a greenhouse, we want to see if we can gain more insight into what, for example, a hailstorm, strong wind, earthquake, rain, sun, cold or heat do to a greenhouse structure," says Egon Janssen, the greenhouse engineer at TNO. "Or monitor how often a greenhouse deck cleaner goes over the deck with what weight and what this does to the greenhouse (gutter)."
Alternative to lab test
For some forty years, TNO has been conducting research on greenhouse profiles in laboratories. This involves subjecting them to a standard test cycle that applies all storms and snow showers to the greenhouse structure during the design life of 15 years, over the course of a few days .
"Because every construction site has different weather conditions, we don't know from the existing greenhouses what residual life they have. On top of that, many greenhouses in the Netherlands are older than the original design life of typically 15 years."
For this reason, TNO wants to build knowledge on the effect of practical loads from wind, snow, crop, deck washers, and even earthquakes on the residual life of the structure. Sensors in multiple greenhouse components such as rods, gutters, trellises and columns, think several dozen per hectare, provide coverage across the entire structure and data insights.
In a pilot project, some parties are now starting to work with sensors in the greenhouse construction. "The question now is whether we get enough and the right insights from the sensor data after one storm, one snow and one greenhouse cover cleaning. Sensors are still very expensive now, so sensors in every greenhouse structure is a pipe dream for now." For now, at least. "Globally, new developments on the application of AI, sensors and monitoring are going very fast."
For more information:
Egon Janssen 
TNO
Tel.: +31 (0)6 53 46 76 64
egon.janssen@tno.nl
www.tno.nl
Stichting Hortivation 
info@hortivation.nl
www.hortivation.nl