Energy efficient greenhouses for Rutishauser AG

Growing plants in greenhouses consumes a significant portion of energy. The greenhouse under investigation features an area of approximately 50’000m2 and a baseline energy consumption of 5 GWh per year. In order to investigate the energy savings potential, detailed measurements have been carried out in the greenhouse as well as a data analysis of past power consumption. One of the main difficulties in greenhouses is the very high fluctuation of temperature with ambient conditions and the low thermal mass of the construction. Based on the investigations several easy to implement suggestions could be made, which allow saving significant amounts of heating energy. Very quickly implemented results were improved temperature profiles for the heating, better control of the ventilation, shading and heat shielding devices, which account for 15-20% energy savings. In addition, exhaust-air heat-recovery systems in certain sections of the greenhouse are recommended for multiple benefits such as reduced energy demand (up to 50% of energy in these sections) and better growth conditions. Finally, improvements in the heat distribution systems will reduce the energy loss by radiation, which will decrease the energy consumption by an additional 15%. Overall, it could be shown that most of the mentioned measures allow very short payback times of less than one year.

Greenhouse (picture courtesy of Rutishauser AG)
Greenhouse (picture courtesy of Rutishauser AG)