ArticleAugust, 2020
Sustainable food production in protected cropping is increasing rapidly in response to
global climate change and population growth. However, there are major gaps in our existing knowledge regarding ways to minimise energy consumption while attaining and maintaining optimum environmental conditions for greenhouse crop production.
This paper details a study conducted in 2019 by a group of Western Sydney University postgraduate students under the direction of Distinguished Professor David Tissue.
In the study, a capsicum crop cultivated in the high-tech greenhouse facility at WSU's National Vegetable Protected Cropping Centre (NVPCC) was analysed in terms of the relationships between key environmental variables and the comparative analysis of energy consumption across different seasons.
According to the paper's abstract, 'the research showed that daily energy consumption varied due to the seasonal nature of the external environment and maintenance of optimal growing temperatures'.
Specifically, total power consumption over the entire crop cycle for heating (via a gas hot water system) and cooling (via pad and fan) was 12,503 and 5,183 kWh, respectively; with heating consuming around 70% of the crop's total energy requirement over the eight-month growing period, from early spring to late autumn.
Regressions of daily energy consumption over each season, designated predominantly for either heating or cooling, indicated that energy consumption in the greenhouse was 14.62 kWh per 1◦C of heating and 2.23 kWh per 1 ◦C of cooling.
'Therefore, changing the planting date to late spring is likely to significantly reduce heating energy costs for greenhouse capsicum growers in Australia', the paper's abstract states.
'The findings will provide useful guidelines to maximise the greenhouse production of capsicum with better economic return by taking into consideration the potential optimal energy saving strategy during different external environment conditions and seasons.'