Effects of lighting, semi-closed greenhouse and split-root fertigation on energy use and CO2 emissions in high latitude cucumber growing

Abstract

Effects of supplemental lighting, semi-closed greenhouse and split-root fertigation on weekly to seasonal heat and electricity use and CO2 emissions in cucumber growing were estimated in Finland. With moderate lighting (170 W m-2 above rows, 60 W m-2 inter-row) in a ventilated greenhouse, seasonal electricity and heat use (MJ kg-1 cucumber) were 20–50 and 10–25, 17–30 and 3–8, 38–55 and 10–18 in spring, summer and autumn to mid-winter, respectively. In summer, a semi-closed greenhouse improved energy use efficiency by 20–30% and split-root fertigation by 0–15%. Raising light intensity and applying inter- row lighting allowed higher yields in autumn to mid-winter without affecting electricity use efficiency. In other seasons, increasing the lighting decreased the efficiency. The emissions largely resulted from electricity use. Direct emissions (kg CO2-eq kg-1) based on propane and electricity from the national grid were 2.5, 1.5 and 3.3 in spring, summer and autumn to mid-winter, respectively. Efficiency of using solar and supplemental PAR was markedly lower in summer than in other seasons. The results provide profile of energy use and emissions and point to ways to reduce them.

Model Simulation of Cucumber Yield and Microclimate Analysis in a Semi-closed Greenhouse in China

“…The energy systems of the semi-closed greenhouse include groundwater sources (hot-and cold-water wells), groundwater energy exchange system (high-efficiency plate energy exchanger), heat pump, the end system (greenhouse heating ducts and ATU), and energy storage system (heat storage tank and cold storage tank). The operation manners of energy systems and climate controls can be referenced in De Gelder et al 2012, Gieling et al (2011), and Kaukoranta et al (2014), which mainly depend on energysaving strategies and commercial crop management practices in China.…”

Reduction of Energy Consumption in the Siberian Agricultural and Food Sector: Priority Measures

“…For example photo cultures are used in Finland when producing lettuce, cucumbers, and tomatoes. Yearly average power consumption are: heating -11 Mj/kg, lightning -32 Mj/kg [7].…”

Assessing heating and cooling demands of closed greenhouse systems in a cold climate

“…In colder climates, winter heating demands are significantly increased and closed greenhouse installations are limited. Experiments in semi‐closed greenhouses with heat recovery ventilation in Finland showed a decrease in the summer heating usage by 35–50%, but no significant reductions throughout the rest of the year . Wong et al .…”

“…In colder climates, winter heating demands are significantly increased and closed greenhouse installations are limited. Experiments in semi-closed greenhouses with heat recovery ventilation in Finland showed a decrease in the summer heating usage by 35-50%, but no significant reductions throughout the rest of the year [12]. Wong et al assessed the closed greenhouse with seasonal storage for the Canadian climate setting and found that annual greenhouse gas emissions could be reduced by up to 86% [1].…”