Gertjan van der Spek is not the first tomato grower in the Netherlands with two transparent energy screens without dehumidification. For him this was the next step in energy saving and by removing the pipes and instead gapping the two screens he hopes to use less than half a cubic meter of gas per kilo tomato.
The idea of double layer energy screens in vegetable growing is not new. A growing number of pepper growers choose this option.
"Pepper plants grow less rapidly, allowing the screens to be closed longer. The step to opt for two screens is smaller for these growers", says climate consultant Paul Arkesteijn, Svensson the Netherlands.
To show that there are also opportunities for tomato growers, a trial was performed last yar at the Improvement Center in Bleiswijk, the Netherlands. With two transparent screens - upper screen a Luxous 1347 FR and the bottom screen a Luxous 1347 FR H2NO with anti-condensation properties - the additional energy saving was 4m3 gas per m2.
When spring showed good test results tomato grower Van der Spek dared to install a second screen underneath the existing one as early as in August. With this step, he hopes to lower his gas consumption to 27m3 and get a yield of of around 63 kg per m².