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Controlled Environment Agriculture – from glasshouse to vertical farm

Topic Overview
Out of House

Is Controlled Environment Agriculture viable?

“We should not consider greenhouses and vertical farms as two diametrically opposed systems. Instead, they should be seen as on a gradient,” says Luuk Graamans, who is currently working as a researcher at Wageningen University & Research (WUR), investigating the feasibility of Controlled Environment Agriculture as a new production system.

“Greenhouses can incorporate the technologies from vertical farms to increase climate control and to enhance their performance under specific climates. The vertical farm is the pinnacle of climate control and may serve situations where such control is warranted, or where interaction with the exterior climate is undesirable.”

WUR and Delft University of Technology (TU Delft) have joined forces to investigate the feasibility of integrating vertical farming as a new production system within the urban energy network.

Luuk’s past research has shown that the effectiveness of Controlled Environment (CE) agriculture depends on a complex interaction between the production method, systems engineering, and the yield and costs of energy, water and CO2.

He says:

“Compared to more traditional food production systems, plant factories are able to achieve higher efficiencies for land area, water and CO2, but generally not for electricity.

“Greenhouses are generally more electricity efficient because of the freely available solar energy. Only in situations with little light and significant energy loss, or perhaps with excessive heat gain across the façade, may a vertical farm come out ahead.

“The important question is which resources you deem (in)valuable, and this is closely related to the local climate, context and market.”

Key opportunities for Controlled Environment Agriculture

Luuk’s research has shown vertical farming may prove to be an effective production system where:

  • energy loss across the greenhouse façade would outweigh the beneficial energy gain from sunlight, for example in cold climates with little sunlight.
  • resources like water, land or CO2 are scarce, for example in arid or densely populated areas.
  • there is a need to strengthen local food production independent of exterior climate, such as areas prone to extreme climate events or where there is dependency on imports.
  • there is potential to integrate the vertical farm into the energy network and provide additional services. For example, densely populated areas that rely on (intermittent) renewable energy sources.
  • energy loss across the greenhouse façade would outweigh the beneficial energy gain from sunlight, for example in cold climates with little sunlight.
  • resources like water, land or CO2 are scarce, for example in arid or densely populated areas.
  • there is a need to strengthen local food production independent of exterior climate, such as areas prone to extreme climate events or where there is dependency on imports.
  • there is potential to integrate the vertical farm into the energy network and provide additional services. For example, densely populated areas that rely on (intermittent) renewable energy sources.

Next steps for Controlled Environment Agriculture

Luuk continues:

“One of the biggest challenges on the production side will be to learn how to properly wield the technology. Although we have a system in which we can control most, if not all, variables of the production climate, at the moment the link between these variables, direct crop responses and crop growth is only understood superficially.

“Advanced imaging and sensor techniques will be able to track the actual plant status in real-time and increase our understanding of these processes. Only then can we truly formulate an optimal growing strategy and take advantage of the extensive climate control that vertical farming offers.

“On the technical side, an important challenge will be optimising the energy use of food production in Controlled Environment Agriculture and to integrate it in the broader energy system. The infrastructure of modern cities and countries is becoming increasingly complex and integrated. Food production should not remain independent but should benefit from the system as a whole.”

Wageningen UR has built new research facilities for vertical farming and crop research in Bleiswijk. These facilities will be used as a tool to study crop response, breeding, pollination and health. The system is designed to continuously track the water, CO2 and energy balance of the crop.

Square Mile Farms bring vertical farms into the workplace by integrating farm-walls, farm-displays and other edible green spaces

Autonomous growing environments or urban farms?

There are many business models:

Large scale production: Nick Bateman, of Growpura, creators of automated hydroponic bio-halls, comments that the ultimate controlled environment would be a fully automated environment.

“The other upside of automation is allowing the system to run in a clean-room environment, monitored entirely by sensors and without sources of contamination brought in by humans. Automation creates a fresher, more natural product free of pesticides, and eliminates the need for a washing process.”

Social innovation: Johnathan Ransom’s Square Mile Farms started with the concept of ‘flat pack farms’ for urban areas and now, through its Office Farmingmodel, is bringing vertical, urban farms to workplaces of big businesses to help them achieve their sustainability and employee well-being goals.

Production in arid areas: Michael Ruggier is the CEO of Airponix, which has developed a smart, sustainable and soilless system that is designed to support the growth of a broad range of food and niche crops with particular benefits where water is scarce. He explains: “In our solution roots are exposed to a nutrient rich fog which is more effective way of delivering the nutrients than any other system such as current aeroponics which spray the roots, or hydroponics which submerges them. It does not require an expensive pumping system or for the water to be changed, so in comparison to hydroponics we use a fraction of the water and can provide double the yield.”

To find out more about other technologies being developed for CEA in the Agri-TechE environment click here.

Nutrient mists enable production where water is scarce

Potential to support diversification

Lindsay Hargreaves, former MD of fresh produce growers Frederick Hiam, says value, freshness and seasonality all determine which crops are suitable for CE production in the UK:

“Being able to grow more exotic crops in East Anglia close to distribution centres would reduce the food miles. Additionally, there are opportunities to grow crops for pharmaceuticals, cosmetics and vaccines within a controlled environment. And then there is seasonality – thirty years ago, the berry market in the UK had a short growing season; now strawberries are a long season as well as high value crop, not just a luxury available for a few weeks. Bringing new crops indoors could open up big markets for UK growers.”

What does the future hold?

An indoor farmer, a technologist and a conventional fresh produce grower give their views on what to expect over the coming years.

Potential to improve the supply chain

Kate Hofman, CEO, GrowUp

“Having been in the business of commercial controlled environment salad production since 2012, starting off with shipping container aquaponics before scaling up, Kate is in an excellent position to comment on the challenges of breaking into the UK leafy green supply chain.

“It will be really interesting to see how the food service world recovers after lockdown – the rough numbers are that supermarket trade was up at least 11% in the last year – so retail still looks like a really good direction to go in. If we want to have an impact on the food system in the UK and change it for the better, we’re committed to partnering with those big retailers to help them deliver on their sustainability and values-driven goals.

“We see the value in opening dialogues with all sectors of the industry, from broadacre to vertical, in terms of research and best practise – there are opportunities for collaboration around things like sustainability and food safety. And there is some overlap between these modes of production – I know several projects where conventional growers have looked into applying controlled environment technology to what they’re doing.

“But our focus is very much as a salad grower that grows a fantastic product that everyone will want to buy. And we’re focussed on bringing down the cost of sustainable food, which means doing it at a big enough scale to gain the economies of production that are needed to be able to sell at everyday prices.”

Container farms offer experiential food experiences

Jack Farmer, CSO, LettUs GrowFeeding foodbanks in Bristol with local produce, whilst developing an automation and control software for vertical farms, LettUs Grow is now pioneering a new concept in farming with its Drop & GrowTM growing units.

“This year is looking really exciting, regardless of what happens with the pandemic – supermarkets are investing to ensure a sustainable source of food production in the UK, which is what CEA provides. We’re also seeing a growth in ‘experiential’ food and retail, like microbreweries, and that’s also where we see our Drop & Grow container farm fitting in.

“The smaller model, Drop & Grow:24, is primarily focussed on people entering the horticultural space, be they entrepreneurs, new growers, agriculturalists who weren’t previously into CEA. We expect it to be one of the most productive, ethical, and easy to use container farms on the market. It is a core part of our strategy to be the leading technology provider in this space.

“Everyone in the vertical farming space is going to hit a crossroads, because vertical farming, with its focus on higher value and higher density crops, is effectively a subset of the broader horticultural sector. All the players in the vertical farming space are facing a choice – to scale vertically, and double down and try to capture as much value in that specific space through vertical integration, or to diversify, and take their technology expertise broader. ”

Controlled Environment Agriculture vs outdoor field crops?

James Green is Director of Agriculture at G’s, one of Europe’s leading fresh produce growers. He explains:

“There’s a spectrum from outdoor grown field crop, which is what G’s does, through to various polytunnel/greenhouse set-ups, all the way to vertical farming under fully artificial lighting. And there’s a balance in all of these systems between energy costs for lighting, energy costs for cooling, costs of nutrient supply, and then transportation and the supply and demand.”

G’s, which grows about 10,000 hectares of outdoor salads in the UK and Spain, is maintaining a watching brief on the area.

“For commercial production and the finished goods, we still see the economics of CEA as challenging. However, that doesn’t mean it won’t change as technologies, such as solar panels, become more effective and cheaper.

“I think a blended approach, where you’re getting as much benefit as you can from nature but you’re supplementing it and controlling the growth conditions, is what we are aiming for, rather than the fully artificially lit ‘vertical farming’.

“In the short term we see potential for indoor farming to enhance our plant propagation, so that – by using enhanced light or aeroponics technologies – we can get ‘better’ plants that are more uniform or less disease prone for planting outdoors.

“At the end of the day, sunshine is pretty cheap and it comes up every day… but the question is, which production model will work for us in the future?”

Kate Hofman, GrowUp Farms
Grow Up Farms
Jack Farmer, LettUs Grow
James Green, G’s

Briefing last modified March 2022.