Energy efficiency of the lettuce greenhouse production

Abstract

In this paper the influence of greenhouse construction on energy efficiency in winter lettuce production was estimated for different double plastic covered greenhouses in Serbia region. In order to see whether the greenhouse structure influences energy consumption, energy inputs were estimated for lettuce production in four different greenhouse structures (a tunnel and gutter connected structure and three multi-span greenhouses). 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 gutter connected greenhouse with two bays, 3.11 MJ/m2. The highest energy consumption was multi-span greenhouse with thirteen bays, 3.30 MJ/m2. The highest value for output-input ratio was calculated for the multi-span greenhouse with thirteen bays, 0.85 and the lowest for the tunnel structure, 0.47. Regression equations show the nature of the greenhouse structure influence on these parameters.

U ovom radu analiziran je uticaj konstrukcije objekata zaštićenog prostora na energetski bilans zimske proizvodnje salate. Utrošak energije praćen je u četiri tipa objekata zaštićenog prostora i na bazi direktnih i indirektnih energetskih inputa i energetskog outputa određeni su specifični energetski input, energetski odnos i energetska produktivnost. Rezultati pokazuju da je najniža potrošnja energije po jedinici površine ostvarena u blok objektu sa dva bloka, 3,11 MJ/m2, dok je najviša vrednost utrošene energije zabeležena u blok objektu sa trinaest blokova, 3,30 MJ/m2. Najviši energetski odnos ostvaren je u blok objektu sa trinaest blokova, 0,85 a najniži u objektu tunel tipa, 0,47. Jednačine regresije su ukazale na prirodu zavisnosti energetskog bilansa sistema od izabrane konstrukcije objekta zaštićenog prostora.