Contain your excitement

Vertical farming is being touted as the future of sustainable food, but a recent report found the sector may not be as green as it sounds. Jack Thompson visits to find out more.

LogoThis article is part of a new series by Wicked Leeks, Sustainable Cities, exploring what sustainable food means to those living in the city.

You could easily mistake the inside of a vertical farm for a scene in the matrix, colourful neon LED lights flooding through the lettuces stacked in their orderly chambers.

Vertical farms are popping up in urban spaces and in the fringes of cities, in container units, repurposed car parks and old industrial spaces; places where we’d never expect to see farming. It’s futuristic and exciting; they even use the same technology in space. But whether it should be the future of our food is still a disputed concept.

In an unassuming 40-foot container unit nestled behind Elephant and Castle station just south of the river in London, vertical farming company Crate to Plate has access to nearly an acre of growing space. That’s 0.9 per cent of the growing space needed to grow the same amount horizontally.

“It’s all in the vertical,” explains founder and former investment banker Sebastien Sainsbury, as he shows off Jezabel, his £120,000 ‘farm’, which looks more like a high-tech laboratory.

“There’s about 6,000 heads of lettuce,” he explains. “We harvest 600 heads every week, irrespective of climate.

“It’s about controlling the environment, to the minutest detail,” he says. “We don’t use any pesticides, fungicides or herbicides”, conveniently leaving out synthetic fertilisers frequently used in the sector.

Step into the matrix: this 40-foot container has nearly an acre of vertical growing space. 

Vertical farming has obvious virtues for Crate to Plate’s mostly restaurant clientele which includes Michelin star venues like Oliver Dabbous’ Hide and Francesco Mazzei’s Sartoria, which laud its taste, freshness and aesthetics.

It’s easy to understand why; the lettuces are mesmeric, almost other-worldly, floating on the walls as if they were wallpaper. And the proximity to central London means that it can be delivered within 24 hours of harvesting.

But according to Sainsbury, the biggest green win is all in the water.

“We use about 95 per cent less water than traditional farming where the soil absorbs 80 per cent and it doesn’t get down to the roots,” he says.

There is no soil in the vertical farm as it runs on a hydroponic system (food produced without soil can’t currently be certified as organic), where plants are fed by a secret recipe of nutrient water that trickles down from the roof and is absorbed by roots through a foam-like material. Once the water has filtered down to the bottom, it is then recycled back into the system.

But is water usage such an important topic in a country where rain seems to always be in abundant supply?

“It may not be a big deal in the UK,” replies Sainsbury. “But think of the other places we get our produce from.”

He has a point; the UK imported over £11.5 billion of fresh produce last year and Spain, which supplies 32 per cent of our veg and 20 per cent of our fruit, is dealing with a major water crisis and has suffered droughts for many decades with rising temperatures caused by global warming. 

Hydroponic systems like this use 95 per cent less water, but is it such a big issue in rainy Britain? 

So there are valid benefits to cutting pesticides and water use. But some of the less substantiated claims around vertical farming being a silver bullet to sustainable food don’t always hold up, according to a recent report that questioned people under anonymity working in vertical and other controlled atmosphere farms.

“Too frequently we see farms relying on vague and outdated claims when it comes to the true environmental impact of their operations,” says Henry Gordon-Smith, co-author of the report.

Energy usage is high on the list of concerns, as controlled atmosphere farms use on average a little over 100 times more than traditional agriculture, unsurprising considering they are replacing the sun with LED lights.

With a decent size vertical farm costing between £10 to 20 million, investor pressure to perform financially could explain the greenwashing and unwillingness to disclose accurate sustainability figures, according to another co-author Kylie Horomia.

Vertical farming went through and is still going through an explosion of investment,” Horomia says. “People are guarding themselves. I mean they’re wanting money from investors so they can’t afford to do anything but shine.”

Ownership is another point of consideration in how these farms fit into the future of sustainable food in the UK, where there is a growing awareness that people, workers and livelihoods should be central to any green transition.

Vertical farms require huge capital investment – Vertical Future received a £21 million pound investment recently from five individuals and two funds – meaning their backers are usually multinational hedge funds or venture capitalists, driven by distant shareholders whose primary interest is profit.

As Jamie Burrows, co-founder of vertical farming technology and research company Vertical Future, says: “There’s always a financial undercurrent that they need to meet in any investment that takes place.”

But that’s not to say traditional land farms in the UK, sustainable or not, will ever be able to meet all of our food needs. “With climate change, the dynamics of international food distribution are going to completely change,” adds Burrows.

“There will come a day when there will be a whole list of products that will no longer be grown in southern Spain, because the economics don’t work,” says Burrows, who sees domestic vertical farming as a way of replacing this potential gap in supply.

 Vertical farms can use up to 100 times more energy than traditional farming. 

While Sainsbury is trying to grow varieties like tomatoes and chilli peppers, Burrows has a more practical view of the industry’s ceiling and it’s about 1.5-2 metres.

“Anything that has a huge root system or is very tall isn’t going to work in a vertical farm because our business model is built on vertical layers,” he explains. “The bigger the plant, the more energy you to have to use to project the LED light on the plant.”

“It’s true we can grow these things in a vertical farm, but the real question is should we be growing them?”

So is vertical farming the answer to a sustainable local food supply, growing pesticide-free produce within metres of consumers? Or is it further alienating us from a connection with the land and nature, and placing the future of food into the hands of entrepreneurs and private investors, well-intentioned or not?

The jury is out on a binary decision, and there may well not be one anyway. As Horomia puts it: “No matter about it, it’s the future of our food. But it’s not the only future.”


Leave a Reply

    1. The Crate to Plate project is paired with renewable energy, which is great.

      However isn’t there an opportunity cost for that renewable energy that could be used elsewhere, when plants could use the natural energy of the sun instead? It seems funny to use tech to transfer the sun’s energy to electricity (with all that waste along the way) to transfer it back into light to grow food?

  1. Very interesting article, and I’m really glad Wicked Leeks is continuing to report on this topic, along with all its other great work.

    From my point of view, the “secret recipe of nutrient water” is at the heart of vertical farming’s environmental sustainability. Energy is an important part of it too, but is perhaps easier to solve. There are clearly environmental benefits to controlling a crop’s surroundings (no ‘pesticides’ etc), but it all depends on how otherwise freely available soil nutrients are reproduced artificially.

    Right now, (and somebody please correct me if I’m wrong) it doesn’t seem to be possible to farm hydroponically without:
    – natural gas (synthetic nitrogen fertiliser)
    – mining (potash and rock phosphate)
    – industrial processes needed to produce the soluble micronutrients made available by living soil.

    If hydroponic nutrients can be produced efficiently organically, we’d really be onto something, but ‘promising research’ on organic nutrients has yet to materialise into commercial products.

    When it comes to energy, it does seem there’s a lot of electricity used in these farms, but LED grow-lighting technology will continue to improve. Renewables could be used to supply the electricity, but given that the plants are in a completely controlled environment, you could actually flip day & night and use low-carbon baseload grid electricity during the night to provide most of that LED light and use more of the waste heat. There are challenges here, for sure, but they seem easier to solve than the nutrient one.


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