Energy Transition
Energy is precious. Fossil energy also causes CO2 emissions. That is why the greenhouse horticulture sector is working on the transition to renewable energy. The Greenhouse Horticulture & Flower Bulbs Business Unit of Wageningen University & Research plays an active role in this, including research into new cultivation systems and new materials. Jouke Campen (Greenhouse Horticulture Energy Research Team): “Our goal: a fossil-free, economically profitable greenhouse horticulture sector.”
Greenhouse horticulture has long been known as a major consumer of natural gas in particular. After all, greenhouses need to be heated to grow crops. But heating can be done more energy-efficiently and with other, non-fossil sources. Due to new materials and cultivation methods, the sector's energy consumption has fallen enormously in recent years. Moreover, horticulture is now an important producer of energy, such as electricity and heat from geothermal energy.
Energy program
The Energy Program of the Greenhouse Horticulture & Flower Bulbs Business Unit works towards a climate-neutral greenhouse horticulture sector that is economically profitable. The program aims to reduce energy consumption through the use of new greenhouse covering materials and screens.
Humidity, lighting and CO2
A well-insulated greenhouse mainly uses energy for moisture removal. Energy-efficient dehumidification is therefore also an important point in the program. The use of lighting, which is necessary for cultivation in the winter months, in combination with natural light is being studied. Similarly, the use of CO2 is also examined, which is limited because gas is no longer used for heating.
Together with entrepreneurs
Greenhouse climate and energy are not separate: almost every intervention in the greenhouse climate has consequences for energy use, and vice versa. Every change in light, temperature or humidity has an effect on the cultivation, yield and quality of the product.
Campen: “Our computer models calculate new cultivation concepts and study the effect of interventions in climate and energy use on the crop. We also investigate innovations in climate and energy management in practice. For this we work intensively with entrepreneurs in horticulture and the supply industry.”
Our contribution to fossil-free greenhouse horticulture
Wageningen University & Research plays an active role in the transition to renewable energy and limiting the use of fossil fuels. For example, WUR is closely involved in the innovation program Greenhouse as an Energy Source. Topics on which WUR conducts research include:
- Greenhouse climate
- Air quality
- Conditioned cultivation
- Het Nieuwe Telen (The New Cultivation)
- Lighting
- Greenhouse covering materials and screens
- Electricity-producing greenhouses
Energy
Greenhouse climate
Air quality
Less frequent opening of greenhouse windows may result in the accumulation of harmful components such as ethene (C2H4) and NOx (NO and NO2) in the greenhouse. This may be the case when CO2 is applied via flue gases from a WKK (combined heat-power installation).
But there a more potential sources of these harmful gases, such as pulsfog systems, leaf blowers, trucks in loading bays, or chimney outlets too close to the windows. Too high concentrations of these components may - especially in winter - cause serious crop growth inhibition.
There still are many questions around greenhouse air quality. The effect thresholds for the various crops, e.g., are not yet known, or in other words, at which concentration of the various components does damage occur? The sensitivity of the crops in the various development stages and whether there is a difference in sensitivity under continuous exposure or at peak concentrations is also unknown. And the effect of the greenhouse climate (temperature and relative humidity) on crop sensitivity is still unclear.
The business unit Greenhouse Horticulture is therefore, together with commercial partners, investigating the various questions around greenhouse air quality. The researchers of Wageningen UR Greenhouse Horticulture are focussing on the questions around crop sensitivity. Partners are dealing with questions around improvement of the technique, such as optimisation of the measuring methods, the more accurate supply of CO2, and the prevention of harmful components.
