Food security: vertical farming sounds implausible until you concentrate on its energy use

An organization in Scotland has unveiled what it claims is arguably the world’s most technically advanced indoor farm. Intelligent Growth Solutions’ vertical farm uses artificial intelligence and specially designed power and communication technologies. The firm says this reduces energy costs by 50% and labour costs by 80% compared to other indoor growing environments, and may produce yields of as much as 200% greater than that of a conventional greenhouse.

Vertical farms like this aim to minimise water use and maximise productivity by growing crops “hydroponically” in small amounts of nutrient-rich water stacked in a climate-controlled constructing. But it’s essential to recognise that the increased productivity of indoor vertical farming comes at the associated fee of much higher energy usage resulting from the necessity for artificial lighting and climate control systems.

By 2050, global food production might want to increase by an estimated 70% in developed countries and 100% in developing countries to match current trends in population growth (based on production information from 2005-2007). But in countries that already use the vast majority of their land for farming, this is less complicated said than done.

The UK, for instance, uses 72% of its landmass for agricultural practices but imports nearly half of the food it consumes. To improve domestic food security and stop natural habitats from being destroyed for brand spanking new farmland, countries resembling the UK need to contemplate latest methods of food production.

Urban farming presents a singular opportunity to grow food on already developed land, increase domestic food production and minimise the gap food travels. Since the publication of Dickson Despommier’s 2010 book The Vertical Farm: Feeding the World within the twenty first Century, vertical farming has turn into synonymous with urban farming. Although the agricultural skyscrapers illustrated in Despommier’s book are yet to be realised, the concept of growing food vertically has captured the minds of designers and engineers alike.

The energy demand related to vertical farming, nonetheless, is way higher than other methods of food production. For example, lettuces grown in traditionally heated greenhouses within the UK need an estimated 250kWh of energy a 12 months for each square metre of growing area. In comparison, lettuces grown in a purpose built vertical farm need an estimated 3,500kWh a 12 months for every square metre of growing area. Notably, 98% of this energy use is resulting from artificial lighting and climate control.

Even with the reductions promised by Intelligent Growth Solutions, the energy demand related to most vertical farms would still be very high, which positions vertical farming in a gray area. On the one hand, the world needs to provide more food, and then again, it needs to scale back energy use and the production of greenhouse gases.

Urban alternatives

But indoor vertical farming isn’t the one solution to grow food in cities. A plethora of naturally lit methods also exist, from raised beds in communal gardens to rooftop aquaponic systems that grow food with the assistance of fish. These methods all require less energy compared to vertical farming because they don’t need artificial lighting.

When viewing cities from above, it is obvious to see just what number of flat roofs are left vacant and the agricultural opportunities they represent. In town of Manchester within the UK, unoccupied flat roofs account for an area of 136 hectares, representing one third of town’s inner urban area.

Gotham Greens in New York and Lufa Farms in Montreal, for instance, are each business farms that use vacant roof space to grow food in naturally lit hydroponic greenhouses. Given the success of such projects and the world of roof space available, it seems strange that so many firms would skip ahead to methods of food production that also need a number of costly development, in addition to more energy to operate. Although they will’t grow as much food, rooftop greenhouses need at the least 70% less energy for every square metre of growing area than artificially lit vertical farms.

Having designed and built a rooftop aquaponic system myself in an ex-industrial constructing in Salford within the UK, I’m surprised that more firms should not considering and maximising the opportunities presented by naturally-lit urban environments. If nothing else, I imagine we needs to be exploring the potential of naturally lit environments before we delve into dimly lit buildings where special technologies, artificial lighting and air handling units are needed to provide food.

There is little query that vertical farms will play a giant role in urban farming and agriculture in the longer term. But when considering any approach to food production, we’d like to know the impact and energy use of the practice to make sure it’s a sustainable and comprehensive response to global food demands. Vertical farming currently requires a number of energy, which is able to hopefully decrease over time as firms like Intelligent Growth Solutions make technical advances. But in the intervening time, the practice of vertical farming remains to be a great distance from being a sustainable approach to agriculture.