Greenhouse Horticulture in the Netherlands has set itself the task of having halved its primary energy consumption per unit of production at the end of the century, compared to 1980. As a result, a large number of energy-saving measures have been suggested to meet this target. In this book a simulation model is presented that can be used as a tool to judge the measures proposed. The model describes the dynamics of the greenhouse climate, the components of the heating system and the greenhouse climate controller with a time resolution of up to 1 minute. Also, the photosynthetic activity of the canopy is described. Consequently the model takes account for the complicated horticultural practice. The simulation model is constructed from sub-models. Each of these sub-models is discussed in detail. The sub-models for the heating circuit, the condenser and the short-term heat storage facility were newly developed. Therefore, these parts of the model are discussed extensively. The greenhouse climate controller and the greenhouse climate simulation are described integrally, however briefly, because these parts of the model are a reflection of the current state-of-the-art. To proof the quality of the simulation model, computations are compared to measurements on a rose crop in a research facility. These comparisons are made both with a high resolution on a small time scale (10 minutes) and with aggregated values on a large time scale (year round daily results). To analyze the prospects of energy-saving measures in greenhouse cultivation, the simulation model was applied to nine energy-saving options. The results of the model on these options with respect to energy consumption and biomass production are compared with a reference situation. The reference situation comprised a customary greenhouse growing tomatoes in the Netherlands. From the options evaluated, the application of combined heat and power and alternative cladding materials appeared to yield the largest decrement of specific energy consumption (the energy consumption corrected for production effects).

/pdf/analyzing-energy-saving-options-in-greenhouse-cultivation-4e3ua98ls6.pdf

Analyzing energy-saving options in greenhouse cultivation using a simulation model

Temperature Gradients in a Partially Shaded Large Greenhouse equipped with Evaporative Cooling Pads

http://directory.umm.ac.id/Data%20Elmu/jurnal/S/Scientia%20Horticulturae/Vol84.Issue3-4.June2000/1458.pdf

High vapour pressure deficit influences growth, transpiration and quality of tomato fruits

Greenhouse crop transpiration simulation from external climate conditions

The standard FAO methodology for the determination of crop water requirements uses the product of reference evapotranspiration (ETo) and crop coefficient values. This methodology can be also applied to soil-grown plastic greenhouse crops, which occupy extended areas in the Mediterranean basin, but there are few data assessing methodologies for estimating ETo in plastic greenhouses. Free-drainage lysimeters were used between 1993 and 2004 to measure ETo inside a plastic greenhouse with a perennial grass in Almeria, south-eastern Spain. Mean daily measured greenhouse ETo ranged from values slightly less than 1 mm day−1 during winter to values of approximately 4 mm day−1 during summer in July. When the greenhouse surface was whitened from March to September (a common practice to control temperature), measured ETo was reduced by an average of 21.4%. Different methodologies to calculate ETo were checked against the measurements in the greenhouse without and with whitening. The methods that performed best in terms of accuracy and statistics were: FAO56 Penman–Monteith with a fixed aerodynamic resistance of 150 s m−1, FAO24 Pan Evaporation with a constant Kp of 0.79, a locally-calibrated radiation method and Hargreaves. Given the data requirements of the different methods, the Hargreaves and the radiation methods are recommended for the calculation of greenhouse ETo because of their simplicity.

https://link.springer.com/content/pdf/10.1007%2Fs00271-010-0233-5.pdf

B.J Bailey

Papers

The effect of climate on tomato transpiration in greenhouses : measurements and models comparison