An active blogger for the Dutch vegetable magazine, Groenten & Fruit Actueel, Arjan Vedder is the second generation in a soon thirty-year-old family business. In the mid-eighties Wim Vedder started growing aubergine plants in Rockwool and so the search for technological advance began.
Twenty years later, with a single layer energy screen in his Venlo greenhouse, Arjan was battling to find ways of reducing heating costs without sacrificing warm temperatures.Compared with some of the other vegetables grown in the Netherlands such as tomatoes or even peppers, young aubergines plants are very energy intensive. Arjan maintains the greenhouse temperature at 23°C for the first few weeks to ensure strong and healthy plants. During the summer half of the year this is a moderate expense, but for the winter crop this requires a substantial energy investment.
The Vedders take full advantage of their gas-driven heating system by selling the surplus energy to the local electricity distributor, a typical arrangement for Dutch growers. In this situation, reducing gas consumption has the additional benefit of generating a second income – besides any environmental aspects. So for Arjan, the idea of supplementing his single closed energy screen with a second layer was highly motivated. The chosen second layer, LUXOUS 1243 D, was installed and fully functional by January 2009. It was chosen for its slightly open structure (1/15), allowing greater management of humidity throughout the greenhouse and beneath the top layer. Already this winter, Arjan has seen his gas consumption drop by 3 to 4 m3 per m2, and has no problem maintaining the greenhouse temperature during the coldest days and nights of winter.
As usual, Arjan is again looking ahead: ‘‘I’m looking forward to seeing how much gas I save this next winter when I will be able to use the system more efficiently – and throughout the whole season’’. Another opportunity he sees is using the LUXOUS 1243 D on its own, as the crop develops and excess humidity can easily become a problem. Beyond this winter, he aims to continue finetuning his growing climate with the goal of increasing the nursery’s production of high quality aubergines and further decreasing fuel consumption.