vertical farming

Vertical farming: between hope and hype?

In Blog by Elta Smith

Imagine a farming future that is 100 times more productive on the same amount of land. Few or no pesticides are required. As much as 95% less water is required. No soil is needed. Crops can be grown year-round, with less labour and where the labour requirements are consistent and sustained across the year.

In this future, crops are grown closer to the consumer – on the edges of or even in the city centre. Places that couldn’t previously produce their own food due to extreme environmental conditions (such as the Middle East) can now produce enough food to be self-sufficient.

That future is becoming possible with vertical farming.


What is vertical farming?

Vertical farming is the practice of growing plants indoors under artificial lighting conditions. Multiple levels – stacked trays – of planting containers are used, reducing the land necessary for cultivation, and enabling production pretty much anywhere a building can be constructed.

Bringing cultivation indoors has been successfully achieved at commercial scale using greenhouses for more than 100 years. These systems harness the benefits of greater control over growing conditions such as water, temperature, humidity, and air quality, but still rely on natural light for their success.

Herein lies the rub. Vertical farming, by definition, requires artificial light to reach plants that would not see natural light under the layers of plants above them. And despite huge advances in recent years, LED lighting is still very expensive.

Although the costs of vertical farming are coming down, energy consumption is still perhaps the biggest barrier to the industry truly taking off. We can produce leafy greens of comparable quality to those grown in more conventional ways but at a much higher cost

Initial start-up costs are also high, up to 10 times higher than a high-tech greenhouse, which leaves vertical farming for the time being very much in the preserve of venture capital.

A vision for vertical farming

The modern concept of vertical farming was popularised about 30 years ago through the vision of New York-based academic Dickson Despommier. Concerned about the effects of conventional agriculture on climate change and environmental pollution, Despommier and his colleagues began dreaming of floor-upon-floor of indoor crop cultivation – skyscrapers of edible plants to feed growing urban populations and in the process reduce greenhouse gas emissions from food transported over long supply chains. Pollution from fertilisers and pesticides could be reduced or eliminated. This vision of vertical farming even starts to address the problem of ever-expanding land use for conventional farming encroaching on space for wildlife and wilderness. 

Vertical farming creates the possibility of growing food in places where it could not previously be grown – conceivably in any urban environment, and in countries with limited access to viable agricultural land. This potential has meant that Japan was a pioneer in the technology, with small-scale vertical farms in operation since the 1970s, long before Despommier envisioned skyscrapers of leafy greens.

In this way, vertical farming could help address food security concerns, which have only increased in the wake of the COVID-19 pandemic. ‘Urban agriculture’ that enables food production close to the consumer could improve resilience following natural and human-induced disasters. Long supply chains that risk disruption due to unforeseen events could become a much less potent threat.

Bringing food production closer to city centres could also help to address social problems. Food deserts could be reduced or eliminated, helping to address inequalities in access to healthy food. For farmers themselves, vertical farming could provide a countercyclical income stream to grow crops out of season—think strawberries in the wintertime—helping to support those working in this highly challenging yet utterly essential sector.

Caught between hope and hype?

Since vertical farming was originally conceived, investment in the technology has skyrocketed. In 2019, the global market size was estimated at USD 2.9 billion. Nearly three times that level of investment was achieved in 2020. Market forecasts predict a 20-25% compound annual growth rate over the next 5-7 years.

But the concept of vertical farming has very much come back to earth. Today if you Google ‘vertical farming’ you’ll find hundreds of articles outlining in sharply contrasting terms the opportunities and limitations of the approach. Celebrations of the potential benefits alongside critique of the costs and related technology constraints. The original idea of skyscrapers has largely been replaced by more modest warehouse-style systems of stacked trays of plants, typically grown in a single storey building.

The contrast between the vision and the reality remains stark. Innovation in lighting technology hasn’t brought energy costs down sufficiently to match conventional farming. Most vertical farms produce salad leaves and herbs, leading to charges of elitism in the sector. Because the costs are significantly higher than conventional produce, vertical farming is not yet able to address inequalities in the way that early visionaries hoped. Harmful environmental externalities have not been fully ‘priced in’, underselling the benefits of reduced emissions, resource use, pollution and biodiversity loss.

Vision meets reality

Encouraging signs of a shift towards mainstreaming vertical farming have appeared in the last five years, however. Some of the world’s largest vertical farms have been built in the smallest countries. Abu Dhabi, which imports about 90% of the food it consumes, has built one of the biggest vertical farms in the world. Singapore also imports more than 90% of its food. Supply chain challenges resulting from the COVID pandemic inspired the Singapore government to launch a grant scheme supporting more local production, including vertical farming. Both countries aim to meet 30-40% of their nutritional needs with homegrown produce by 2030 and vertical farming is a critical component of that objective.

The U.S. currently has the largest vertical farming sector in the world. Europe is not far behind. YASAI is a spin-off of ETH Zurich—one of the world’s premier universities for science and technology. Amongst other endeavours, the company has plans for a 100,000 sq m production plant and research hub in an abandoned limestone mine in Switzerland. Once complete, it can potentially yield more than 3,500 tonnes of fresh produce a year. Committed to the principle of circularity, which means recovering energy and recycling waste, YASAI aims for zero waste, zero plastic and zero food miles

This is possible in part because vertical farming can dispense with rooting plants the traditional way in a soil medium and instead grow plants in water (hydroponics) or increasingly, using aquaponics – an approach pioneered by NASA in which the roots are left exposed to the air, held in place using foam and misted with nutrient-filled water. These closed looped systems not only use less water, but also recycle that water and the nutrients.

Technology developments will certainly help to improve the size and scale of the industry. Robotics has facilitated automated planting and harvesting. Sensors detect changes in colour and other features which can point to the need to adjust light or address problems with disease. Artificial intelligence enables high-powered processing of the data collected by those sensors.

A combination of technology advancements and increasing consumer demand for healthier and more environmentally friendly foods has created an opportunity for vertical farming to play an important part in our food systems. The COVID-19 pandemic has made governments more concerned about supply chain resilience, speeding up investment in production systems that can address these concerns.

But is vertical farming the future of agriculture? There’s no such thing as a silver bullet when it comes to complex problems, but I’m optimistic that it’s only a matter of time before vertical farming will find its place amongst the increasing number of people and planet friendly solutions to the many challenges our food systems face.