The herbs in your future online supermarket delivery may be grown not in a field in a distant country, but in a shed on the outskirts of a nearby city. This week, UK online supermarket Ocado on vertical farming, an industry that advocates say can produce food in a more environmentally friendly way. But will the investment really allow Ocado to deliver greener food?
Ocado has taken a majority stake in Jones Food, which runs Europe鈥檚 biggest vertical farm on an industrial estate in Scunthorpe. It has also invested in a joint venture with a further two firms 鈥� Priva based in the Netherlands and 80 Acres based in Ohio 鈥� involved in vertical farming.
Vertical farming sees crops grown indoors under lights, in racks several metres tall. The technology expands production upwards and so requires less land. It also means that crops can be grown closer to where they will be consumed. That partly explains its success in Asia, with commercial vertical farming in Japan dating back more than 15 years.
Advertisement
Indoor salads
The sector has a much more recent history in Europe, emerging over the past five years. In Scunthorpe, basil and other herbs, watercress and leafy salad are grown in water under LED lights on racking that would collectively cover about 5000 square metres.
鈥淭here鈥檚 always been an energy and employee argument which has probably held back vertical farming over the past decade,鈥� says James Lloyd-Jones of Jones Food. The efficient nature of LEDs has been key to addressing that, along with lower energy lighting that just emits the blue and red wavelengths that plants can use. Fertiliser use 鈥� farming鈥檚 traditional big energy burden 鈥� is 鈥減henomenally reduced鈥�, Lloyd-Jones says.聽Pesticide use is zero because few insects make it into the indoor environment.
The labour-intensive nature of vertical farming has been tackled through automation, to a degree, with just five of the company鈥檚 eight staff running the farm at any one time. Other UK-based companies are .
Increased automation
Stewart McGuire of Ocado, which has pioneered the use of robots for packing groceries, says the company wants to increase automation, be more efficient with lighting and grow a wider variety of crops 鈥� probably beginning with tomatoes, cucumbers and berries.
He says issues with outsourcing food growth to other countries 鈥� 鈥渋ssues around deforestation, or mega-farm impacts, or carbon emissions鈥� 鈥� will favour local production in vertical farms. Vertical farming could also address food security concerns, says McGuire, and packaging could be reduced because food from vertical farms will travel shorter distances.
Do the green claims stand up? Some studies suggest not: one US researcher has calculated that the electricity bills associated with vertical farming may translate into that effectively wipe out any 鈥渇ood miles鈥� savings from growing locally.
Too much hype?
鈥淚 think there鈥檚 a lot of hype about it,鈥� says Tim Lang of City, University of London. 鈥淸Vertical farms] have become more possible, more feasible because of LEDs, but they are still energy intensive.鈥�
Given that the herbs and leaves now grown in vertical farms are largely used for the 鈥減rettification鈥� of meals, they are unlikely to address food security, Lang says. He prefers the idea of traditional greenhouses, potentially on city rooftops, as a way of bringing food production closer to demand.
Vertical farming could hold some environment benefits, says Duncan Cameron at the University of Sheffield, UK, because it requires much less fertiliser. Food waste is also 鈥渞educed hugely鈥�, he says, because of the 鈥渏ust-in-time鈥� nature of indoor farms.
But Cameron says vertical farming still involves huge amounts of water. 鈥淎nd the fact remains it all takes electricity,鈥� he says. While some of Jones Food鈥檚 UK electricity supplies come from solar on its roof, and the UK power grid is more than 50 per cent low carbon today, that鈥檚 still a lot of fossil fuel use.
Mostly, we need more analysis about vertical farming versus traditional alternatives. 鈥淲e need to be cautious about the sustainability claims until we know how sustainable it is,鈥� says Cameron.
