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

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)