Tielemans Groentekwekerij opted for a hybrid light installation where the existing HPS installation was expanded with Philips LED. LED has a lower heat output which allows better control of the greenhouse temperature compared to HPS. This reduces the need for ventilation and the loss of CO2 from the greenhouse. René Tielemans, the Owner, said: “A greenhouse with only HPS lighting produces too much heat, so we can’t add additional conventional lighting. A greenhouse that is too hot no longer stimulates growth-producing too much plant and not enough cucumbers.”
Tielemans added: “We can now extend the growing season and mimic the amount of light on a clear spring day in the winter. This enables us to supply cucumbers to our customers all year-round.”
The LED installation is controlled by the GrowWise control system (GWCS): a link to the climate computer allows the light to be dimmed and controlled and retain control over the amount of light. Stappers, Plant Specialist, Signify, said: “This provides you with much more flexibility to determine the light level separate from the heat in the greenhouse. You can optimally adjust the light intensity according to the needs of the crop.”
Tielemans can now light their plants according to the needs of the crop and be more flexible with the costs of electricity consumption. René explained: “Less energy goes in, and more light comes out, even when electricity prices are high, we can decide for ourselves to temporarily use the grow lights less. That way we also save even more on our energy bills.”
The Director said: “We are progressive and sometimes we go against the grain. For example, in 2011 our company was the first to supply cucumbers with an environmental label, now known as Planet Proof. This has now become the norm. We were also the first in the southern part of the country to start sealing our own cucumbers.”
Tielemans, for example, sees growing cucumbers under LED lighting as a mutual learning process that still needs to mature. “The experience of the growers is also very important for Signify to make light recipes even better. We learn a lot from and with each other and that creates a win-win situation.”
