Energy consumption for different greenhouse constructions

In this paper the influence of greenhouse construction on energy efficiency in winter lettuce production was estimated for four different double plastic covered greenhouses in Serbia region. Plastic coverings were introduced in this region as a mean of making the plant production more energy efficient. Additionally, as a means of lowering energy consumption, tunnel structures were proposed. In order to see whether the greenhouse structure influences energy consumption, four different double plastic covered greenhouses. Two tunnel types, 9 × 58 m and 8 × 25 m, one gutter-connected structure and multi-span plastic covered greenhouse. The gutter-connected structure was 2 × 7 m wide and 39 m long while the multi-span structure was 20 × 6.4 m wide and 42 m long. On the basis of lettuce production output and the energy input, specific energy input, energy output–input ratio and energy productivity were estimated. Results show that the lowest energy consumption was obtained for multi-span greenhouse, 9.76 MJ/m2. The highest energy consumption was obtained in tunnel, 9 × 58 m, 13.93 MJ/m2. The highest value for output–input ratio was calculated for multi-span greenhouse (0.29), followed by gutter-connected greenhouse (0.21), tunnel 9 × 58 m (0.17) and tunnel, 8 × 25 m (0.15). Results also show that energy productivity can be higher if multi-span greenhouse structures are used.