Food & Climate
Controlled Environment Agriculture (CEA) saves energy and reduces emissions when growing leafy greens in land-locked countries with low grid emission factors or when substituting air freight of short shelf-life produce, according to a new study, that seen by Food & Climate.
The study that titled: “Contextual conditions define maximum energy-use threshold in low-carbon controlled environment agriculture for agri-food transformation” was published in “Nature”.
(CEA) has the potential to achieve food security and lower carbon emissions in agri-food systems.
However, contextual factors such as what is produced and how it is produced determine the feasibility of meeting these goals.
“Here we show how the use of a Maximum Energy-use Threshold, shaped by these contextual factors, can define, identify and enable low-carbon operations”, according to the study which was mad by 3 researchers.
Results support the potential of low-carbon (CEA) over international import when growing leafy greens in land-locked countries with low grid emission factors or when substituting air freight of short shelf-life produce.
Prospective low-carbon energy scenarios help but optimising energy use remains critical.
As (CEA) allows intensive farming with a reduced land footprint, controlled environment agriculture of high energy use crops as a lower-carbon alternative can be supported when the potential for agricultural land substitution and restoration for environmental services is considered, along with other contextual condition.
The 3 researchers are: Shiwei Ng and Olaf Hinrichsen from TUM School of Natural Sciences, Department of Chemistry, Technical University of Munich, Garching, Germany, and S. Viswanathan from Nanyang Business School, Nanyang Technological University, Singapore, Singapore.
Different forms of Controlled Environment Agriculture
Controlled Environment Agriculture, which encompasses setups of varying degrees of automation, environmental control, and monitoring, holds many advantages over conventional open farming.
Production scale and complexity of CEA can vary between different forms, from single storey vertical farms to multi-storeys plant factories with fully standardised and automated processes.
It allows for intensive farming on non-agricultural land with reduced pesticide and water use, while being less vulnerable to climate change. Against the backdrop of more extreme weather patterns and increasing competition for finite habitable land, CEA is primed to meet the global challenge of feeding an increasing world population.
Despite this, the extensive adoption of CEA faces headwinds due to high upfront capital and operational costs, according to the study.
As a result, the trickled-down cost to be absorbed by consumers limits commercial ventures to leafy greens and higher-value produce.
Unsurprisingly, because of the heavy use of artificial lighting and environmental control, rising energy costs have slowed operators’ growth.
This intense energy use is the top carbon emission contributor of CEA. It illustrates the current trade-off between energy, food security, and climate mitigation.
Hydroelectric power in Ethiopia
The estimates of indoor farming configurations exceed the MET allowable in growing the analysed produce for almost all countries. The only exceptions to this are a few scenarios for growing lettuce. This signifies that indoor farming, at its current development, will likely not enable a lower carbon food system as compared to current food imports.
In this analysis, countries such as Ethiopia, Congo, and the Democratic Republic of Congo are outliers and favourable siting locations for siting indoor farming because of their exceptionally low grid emissions from the high utilisation of hydropower and reliance on traditional biomass (charcoal, crop waste, and other organic waste) as primary energy source.
For Paraguay, the cost of being land-locked33 and reliance on distant trade partners position them as favourable for siting indoor farming as well.
Based on literature, almost all of the current CEA setups operate at EUP several multiples of the MET. Only in setups where extremely low energy is used and where short shelf life produce such as strawberries are air freighted, their operations hold potential to be a lower carbon option.
For example, utilising a hydraulic rotating greenhouse setup in Singapore for CEA of lettuce can be achieved at an EUP of 0.021 kWh/kg40, lower than the MET.