Energy-efficient and eco-friendly greenhouses
The growth of several pot species, such as argyranthemum frutescens, campanula potenschlagiana, petunia hybrid, osteospermum ecklonis and pinus pinea partly involves the use of greenhouses. The main disadvantage of such greenhouses is that they are normally constructed by single layer glass that is insufficient as far as insulation is concerned. Therefore, energy consumption for a square metre of greenhouse area may become as much as 20 times higher than its equivalent used for heating a house. Addressing this problem, this EC funded project combined technology for greenhouse building and computer infrastructure with advanced screen material and developed the LEC-greenhouse. This technical solution is anticipated to lead to almost 65% energy savings and consequently diminish the emission of CO(2) that are associated with energy consumption. The LEC-greenhouse is suitable for production of plants with high temperature tolerance and may result in stronger, more flexible and more inexpensive cultivations. The key elements of LEC-greenhouse include a new structural shape for optimised greenhouse design and highly specialised double layer screens used as heat trap and cover. Other features involve a solar collector for exploiting renewable energy, a water reservoir for heat storage and suitable tubes for recirculation of hot water for energy supply. Moreover, the project partners developed suitable simple software for the flexible regulation and control of the climatic environment of the system (temperature, humidity and airflow). The innovative LEC-greenhouse was tested against a traditional glass greenhouse producing the same species of pot plants under the same environmental conditions. It was found that the plants produced with the LEC-greenhouse were of better quality without any requirements for using chemical growth retardants. The production time for all species grown in LEC-greenhouses was increased and energy consumption was only one fifth of the energy used in the reference greenhouse.