Urban agriculture is gaining acceptance as a viable source for fresh produce in the city. A primary cause for this has to do with the spatial constraints of agriculture. Traditional American agriculture utilizes vast amounts of farmland that is generally only usable for part of the year. Conversely, urban farmers utilize areas previously deemed unusable for food production. Vertical farming, one of the most promising sectors of urban agriculture, is perhaps the most efficient form of crop production in history when it comes to the efficient use of space. Unlike other forms of urban agriculture such as community and greenhouse gardens, vertical farming utilizes indoor gardening equipment to produce crops without the use of sunlight. As such, vertical farmers can grow crops year-round inside abandoned buildings and shipping containers.

While vertical farming is an attractive concept due to its versatility concerning seasonality, geography, and spatiality, it has its own constraints. For vertical farming operations to succeed, they must create artificial environments in which plants thrive. The stasis of these artificial environments is dependent on technology that maintains light, humidity, temperature, and air flow. This equipment should also offer farmers affordability and practicality while maintaining these environments.

When it comes to lighting technology LED lighting is leading the vertical farming movement. Here are some reasons why.

Targeted Wavelengths

One of the most defining characteristics of LED grow lights is the pink light they emit. This unique colored light is tied to the overall operational efficiency of the technology.

The white light of sunlight is what we get when all the wavelengths in the visible light color spectrum (red, orange, yellow, green, blue, indigo, and violet—or, ROY G BIV) are mixed together. However, researchers have learned plants respond best to red and blue light wavelengths. Traditional indoor grow lighting—high pressure sodium (HPS) and metal halide (MH) lamps—seek to mimic sunlight at certain times of the year and utilize a large portion of the ROY G BIV spectrum in this process. Conversely, LED grow lights cut out the unnecessary wavelengths by only utilizing blue and red spectrums. The mix of these two colors result in the pink color seen in LED grow rooms. Also, a majority of the operational, financial, and environmental perks of LED lighting are directly attributable to this breakthrough in light wavelength usage.

Spatial Constraints and Heat

Vertical farming takes the efficient use of space for crop production within cityscapes to its extreme. A distinguishing trait of vertical farming is the layering of garden plots on high-tech shelving units with grow lights dispersed between each level. Some farms feature as many as a dozen layers of crops. LED lighting technology can at least be partially credited with the rising popularity of vertical farming as it’s the only horticultural lighting technology that can grow crops on a commercial scale within these stacked layers.

While fluorescent lights could function within vertical farms, they don’t emit strong enough light to fuel the production of most crops. Traditional HPS and MH lighting don’t work for vertical farming either. While these technologies work great for growing crops, they are notorious for emitting excessive heat. The heat issue renders both HPS and MH lights practically useless within the tight confines of vertical farms. LED lights, on the other hand, can be tightly packed in vertical farms because they don’t emit the excessive heat seen with HPS and MH lights.

Energy Efficiency

All indoor gardening operations are costly to operate, and that cost is exponentially heightened when a large-scale vertical farm operates year-round. The primary financial drawback with vertical farming is that of excessive energy usage (which is also vertical farming’s greatest environmental drawback). As vertical farming operations are 100 per cent dependent on indoor gardening equipment, each facet of these complex gardens requires some form of electricity.

The use of LED lights is essential in making vertical farms viable, both financially and environmentally, in the long term. Studies show that LED lighting arrangements are 40-70 per cent more energy efficient than those with HPS and MH lights. On that note, forward-thinking vertical farming companies are also implementing solar power systems to lessen their strain on the power grid.

The urban agriculture movement is rapidly gaining momentum, yet its overall staying power is largely dependent upon the technology that powers its vertical farming operations. Government entities such as the USDA have taken notice of this trend, and the proposed Urban Agriculture Act dedicates government resources to studying LED technology. All things considered, LED lighting is intimately entwined with the progression of vertical farming on an industrial scale, as its cutting-edge technology makes mass production possible within the confines of indoor cultivation.