Coatings can reduce energy consumption
Coatings can reduce the energy consumption per kilo of product and in winter they can also reduce the absolute energy consumption.
A crop that can grow without excessive stress will provide the highest yield and therefore the lowest energy consumption and the lowest CO2 emissions per kilo of product. The insights into optimum growth have changed significantly in recent years, mainly as a result of Next Generation Growing. Initially it served primarily as a way of reducing energy consumption, but it has expanded into a method for optimum use of the light. Coatings are a standard tool for achieving this.
Two important factors here are: the moisture content in the greenhouse and the plant temperature. In the past, 10 to 25% of the annual gas consumption was used for drying out the greenhouse. The aim of this was to activate the crop and to prevent condensation on the crop. Next Generation Growing get away from this, through increased use of energy shading and reduced use of the minimum heaing pipe. Growers have started using more exact methods and need precision instruments as a result. The increasingly refined ReduSystem coatings meet an important need in this regard.
Moisture under control
The source of a high humidity in the greenhouse is evaporation from the crop. High levels of radiation cause the plant temperature to increase; resulting in more evaporation. At some point, the vents will need to open in order to get rid of the excessive moisture which also increases energy consumption. Coatings help to delay that point and therefore result in energy conservation. ReduSol, ReduHeat, ReduFuse or ReduFuse IR can be used, depending on the crop.
At high levels of radiation, an unprotected crop can even become so hot that the evaporation process cannot keep up. In order to prevent dehydration, the plants close their stomata. This however results in the plant temperature increasing even further. This heat stress is detrimental to production; this means that the energy consumption results in fewer kilograms of product and an increase in the CO2 emissions per kilo of product. Once again, coatings - in addition to shade curtains- are an important tool in preventing these types of situations.
Diffuse light = uniform growth
Apart from solving real stress situations, uniform growth also makes a significant contribution to reduced energy consumption. A diffuse coating allows you to distribute the light more effectively. There are no bright light spots that the crop needs to respond to (often in the form of a temporary shutdown of photosynthesis).
In addition, the light penetrates more deeply into the crop, allowing more leaves to contribute actively to the production. Improved horizontal and vertical light distribution both contribute significantly to increased production.
Winter light
In temperate regions, the winter period demands the largest share of the annual energy consumption. It is important to seek maximum gain from the solar energy that is present: as much solar radiation as possible needs to enter the greenhouse. After all, the more solar energy that can be utilised, the less fossil fuel needs to be used. Mardenkro offers a range of measures for this purpose.
First of all, clean glass is very important. The greenhouse roof becomes dirty as a result of algae, dust, soot and deposits of crop protection agents. This can reduce the light by a few percent. This can increase even further if the glass is covered by sand (for example Saharan sand). The greenhouse roof can be cleaned perfectly using GS-4 Xtra.
During the cold period, the condensation on the glasshouse roof has a major effect on the lightlevel in the greenhouse. The way in which condensation takes place is important: large drops can reduce light by 5%. By contrast, research by Wageningen University & Research has demonstrated that a homogeneous water film results in barely any loss of light. The AntiCondens coating creates a homogeneously distributed film of water. Finally, AntiReflect contributes to higher lightlevels, particularly in low-sun conditions.
These three measures combined – cleaning, AntiCondens and AntiReflect – result in 10% more light in the greenhouse during the winter period. This extra solar radiation heats the greenhouse and thereby reduces the use of fossil fuels.
