Standing 12 metres high and with 17 stacked levels of indoor growing space, lit with LEDs in a mixture of red, white and blues – is this really the future of farming?
Lincolnshire-based Jones Food Company’s (JFC) vertical farming system is capable of producing over 400 tonnes of baby leaf salad a year in about 5,000 square metres of indoor space. While there has been development in growing berries, tomatoes and other fruiting plants through these systems, the technology is not yet there to make these crops scalable and JFC is concentrating efforts on baby leaf and herbs. As co-founder Paul Challinor explains, the intention is to make the business commercial from the beginning “rather than having a trial shipping container to look at how it could develop”.
Other city hydroponic growers, such as New York’s Sky Vegetables, a rooftop farm in The Bronx and Growing Underground, a hydroponic farm located 33 metres below the streets of Clapham in London, see their role as an incredibly short supply chain for produce directly into the city.
But not everyone has the same end goal – Grow Bristol has built a vertical farm inside a shipping container on disused land, offering an opportunity for public engagement and connecting urban communities to food, rather than to provide high quantities of salad to the city.
The sky isn’t the limit
The cost of energy – financially and environmentally – remains the greatest challenge to scaling up vertical farming. Even using off-peak energy, and with ever more efficient LEDs coming on the market, the energy requirements are high.
Jaz Singh of Innovation Agri-Tech Group, behind an indoor farm in Bracknell, Berkshire, says: “It doesn’t really matter what time of day your energy is getting produced. It’s about how you cycle it. You can turn the evening into effectively daytime if you’re doing it in a fully closed environment.”
For Grow Bristol’s Oscar Davidson, the future of vertical farming must be in renewables, such as biogas or through anerobic digestion, and ideally on-site generation. This is echoed by another hydroponics expert Kate Hofman, of GrowUp Urban Farms, who says: “From my point of view, the only purpose of doing this kind of farming is to be able to grow food more sustainably…you’ve got to use renewable energy and at the moment it’s too expensive to buy off the grid, so we’ve got to be co-located.”
GrowUp tested a pilot aquaponics urban farm (aquaponics combines raising fish with hydroponics, feeding the plants fish waste), but the system has not proved financially sustainable in its original East London location due to high land rental costs. For Hofman, in theory, the more production moved indoors, the more land can be freed up for other uses, less intensively farmed and even used for carbon sequestering.
Moving beyond salad
Described by Davidson as a “gateway crop to the technology”, salad greens are easy and quick growing (baby leaf salad takes four to five weeks to mature, microgreens just over two weeks), require minimal nutrients and provide multiple crops per season.
But will we be seeing more than just baby leaf and herbs anytime soon? There has been research into crops including sweet potatoes and broccoli, and Singh says he has had some success trialling strawberries. But this poses a greater financial risk with the longer growing time required, and the extra light hours needed.
It all comes back to considering the whole cycle of growing and supply, including energy use. Vertical farming is becoming ever more environmentally and economically sustainable, and if these startups continue to develop at the current rate, a lot more of the food in our fridge could be grown in the tower block down the road.
Is vertical farming organic?
The Soil Association does not currently class hydroponic growing as organic – in the UK, plants classified as organic need to be grown in in soil, whereas in the US, the United States Department of Agriculture (USDA) does not make this requirement.
That said, there are no pesticides involved in the growing at JFC and other hydroponic farms, and the no pesticide factor is often a major motivator for people choosing organic. Hofman says: “I would wonder that the organic movement’s reliance on soil was good for the time it was created, but there’s actually the opportunity to think a bit more broadly about how both systems might be able to coexist or work together.”
Davidson adds: “There are other things to consider, where has that been grown, what was the conditions of the workers who have grown that crop? So yes, we use a lot of energy to grow our crops with our lighting, but we don’t use big agricultural machinery that uses diesel, we don’t use petrol fertilisers, and we don’t use endless amounts of groundwater.”