Feeding the world’s urban masses, while cutting food waste and carbon emissions.
The world’s urban population is rapidly growing and prime farming land is becoming an increasingly scarce asset in many countries. This means more fresh food will need to be grown in the next 35 to 40 years than in the last 10,000 years combined. Securing a reliable food supply for citizens will be a key challenge facing governments around the world in the 21st century.
This is where the simple genius of Indoor Farming enters the picture, with its promise to transform food security for the masses in a manner that minimises environmental impacts and dramatically reduces food waste. So exactly what is indoor farming and how does it work in practice? David Krisztian Zsolt, our Singapore-based Senior Associate Director of Building Services explores this emerging field in the first instalment of this three-part series.
Towering crops, sky high: An ideal solution for overcoming land scarcity and climate extremes
Indoor farming (sometimes called ‘vertical farming’ or ‘urban agriculture’) is the practice of growing agricultural produce in vertically stacked, climate-controlled layers. Think of it as skyscrapers that replace offices or apartments with neatly arranged farming lots under greenhouse conditions, on each level.
Within these neatly arranged lots, either hydroponic or aeroponic methods are used to grow the crops – hydroponic meaning the crops sit in a bowl of water containing rich nutrients or aeroponic where the roots are sprayed with a fine mist. Under both methods, a combination of natural and artificial (LED) lighting is applied to stimulate crop growth as it would occur under direct sunshine on traditional farms.
Singapore, an island city state with 5.7 million residents squeezed into just 720 sq KM (compared to 10,000 sq KM for a city with a similar population like Melbourne) is at the global forefront of indoor farming innovation, given its lack of arable land and a tropical climate, which makes it an unsuitable environment for growing a wide range of crops. Achieving food supply resilience while overcoming these twin challenges of land scarcity and climate extremes are the main drivers behind the growing popularity of indoor farming and the R&D invested into this exciting field. You can hear more about this imperative to achieve food supply sovereignty in episode 6 of our Beca ‘F&B Sound Bites’ podcast here.
The case for Indoor Farming: The world's urban population is rapidly growing and so is demand for food
Agricuture is responsible for 70% of the world's water use
The different types of Indoor Farming
However not all indoor farms are created equal, with the “standard” format described above – vertically stacked enclosed farming lots quite energy intensive due to their heavy reliance on refrigerants such as chlorofluorocarbons (CFCs). Here’s a breakdown of the three most common forms in use today:
- Building-based vertical farms: The “standard” model of indoor farming involves stacking farming lots on top of each other in a tall building. Whilst ideal for space constrained environments such as densely populated urban centres, this approach tends to consume a lot of energy, given the need to keep climate control and hydroponic/aeroponic cultivation systems running 24/7.
- Shipping container vertical farms: An alternative approach growing in popularity is the practice of converting traditional shipping containers into self-contained indoor farming lots, which through the application of some clever engineering solutions can be made quite energy efficient. This will be explored further in Part 2 – Model Container Farms.
- Underground “deep farms”: A third and highly unconventional type of indoor farming are known as “Deep Farms” - vertical farms built in refurbished mine shafts, or underground tunnels. Deep farms generally consume less energy for heating and are also closer to groundwater supplies as temperature and humidity levels underground tend to stay constant due to a lack of natural light and wind exposure.
The challenges of Indoor Farming: Reducing energy and water wastage, cutting carbon emissions
Despite the many benefits of indoor farming, this practice can be a heavy consumer of electricity and water.
- Heavy water consumption: Agriculture alone is the largest consumer of fresh water in the world, accounting for 70% of annual global usage and indoor/vertical farms still require thirsty hydration systems to fuel crop growth.
- Heavy electricity consumption: Special grow lights which replicate the benefits of natural sunlight are another heavy consumer of energy often requiring around the clock operation (and therefore a potential driver of carbon emissions). One grow light alone can easily consume 3,600 BTU (4kW) of electricity.
- Carbon emissions: The 4kW lights also introduce significant heat load into the small, enclosed environment of indoor farming lots. This then presents the need for ventilation and air conditioning systems to maintain indoor air quality – yet another source of energy costs and emissions.
Overcoming these three challenges is the key to making indoor farming a viable solution for securing a population’s food supply under all environmental conditions. In parts two and three we look at how smart engineering techniques can be the answer to making indoor farming a truly ground-breaking practice that delivers on its promise of sustainable food security.