With the second crop in the Winterlight greenhouse at the Energy Innovation and Demo Centre (IDC) in Bleiswijk (NL) coming to an end, it’s time to draw some initial conclusions. The predominant feature of the greenhouse is its extremely high light transmittance.
Growers don’t only stand to gain from this in the winter but in the dark autumn months too: the 10%-plus light gain the designers were aiming for has turned out to be a reality. This not only means that all the partners involved in the project did a fantastic job, but also that the models used in the design process, such as RAYPRO, have proved their worth.
On the crop side, the two high-power crops we grew also yielded good results, despite the thrips problems we had in the first crop. With a few growing weeks to go, the tally is currently 268 cucumbers with an average fruit weight of 407 grams, bringing the total yield to more than 109 kg/m². We are pleased with the outcome on the energy front, too. In this greenhouse, which is single glazed and has two high-transparency screens and a dehumidifier with heat recovery, we used less than 20 m³/m² gas between the end of December and mid-November. But this did mean that we had to buy in around 13 kg of CO2.