Standards and research needed for expansion

One of the contenders for this year’s Australian Macquarie Dictionary’s ‘word of the year.’ was ‘vertical farming,’ but does this mean that this technology has now come of age? Richard Crowhurst reports.

There is plenty of noise in the sector. Environment Secretary Michael Gove mentioned vertical farming at this year’s Oxford Farming Conference and Dubai is investing £31 million in ‘the largest vertical farm in the world.,’ Another company, New York’s Bowery Farming, has raised $90 million to develop indoor farms and a report has suggested that the sector could be worth almost $14,000 million by 2024. Closer to home, LettUs Grow, which develops aeroponic systems, has secured £1 million of public and private funding, but despite such developments, many traditional growers remain sceptical.

“Vertical farming is a relatively new development and is not yet widespread. However, it is attracting a lot of interest from investors and companies,” comments Professor Leo Marcelis of Wageningen University. “A number of companies are making money, but there are also quite a few that are not making money. As with new sectors, a large number of companies will start and a relatively high fraction might go bankrupt, but some might be very successful.”

“We do not think that vertical farming and indoor farming are the solutions for everything,” stresses Tom Könisser, Business Development Manager for lighting developer Signify – Philips Lighting. “It very much depends on where you are and market prices. In the Netherlands we have a surplus of efficient greenhouses with high levels of production and it is very difficult to compete with that. Per square meter the investment costs of vertical farming are five or six times that of a greenhouse, which is a lot more expensive than open field production. We look at each situation to see if indoor or vertical farming can be a solution, and we need to reduce the investment and also increase the output.”

If the techniques are so expensive, why are they attracting so much interest given the low profit margins associated with fresh produce? “The key benefits are a reduction in space and the proximity of these facilities to the end-customer,” explains Nemanja Rodic, Marketing Manager at lighting supplier Valoya, which has just completed a vertical farming installation in Greenland. “Not only is the space reduced by stacking shelves on top of one another, but overall production is more efficient and we see higher yields per square foot compared to a greenhouse. A lot of these vertical farms are within urban environments; shortening the supply chain and satisfying a market segment that prefers fresh produce and is willing to pay a premium for it.”

“You can have full control of the production process, which means you can grow a precisely defined quantity of product at the required quality, independent of location or weather, every day of the year,” adds Leo Marcelis. “By choosing the right settings, full control of the plants is possible resulting in better quality. If strict hygiene protocols are used, pests and diseases can also be kept out without using chemicals.”

Coventry-based Hydrogarden has been developing its V-Farm concept since 2012 and now has systems for both nutrient film technique (NFT) and flood and drain (F&D) production. “We believe the UK is one of the leading European countries in vertical farming due to its early technology adoption and entrepreneurial mentality,” comments V-Farm’s Diane Esvan. “Since 2014 we have never had any fungus infection or other pathogens in any of our trials; we believe our growing technique is pesticide free.”

This ‘clean and healthy’ image helps to explain the global interest. “In Asia farm-gate prices for food which is seen as ‘fresh’, ‘healthy’ and ‘uncontaminated’ are much higher than in the UK, which means that even inefficient facilities can operate at a profit,” explains Dr Rhydian Beynon-Davies, Head of Novel Growing Systems at Stockbridge Technology Centre (STC) in Yorkshire. “Consequently, there is a significant concentration of indoor farms producing fresh produce in Asia as well as in the US.”

STC runs the Vertical Farming Development Centre – a semi-commercial scale facility with two independent compartments, each with a growing area of 110m2, split over four layers. “The facility has control over photoperiod, temperature, relative humidity, air velocity, irrigation and nutrition and there are sensors throughout for RH, temperature and CO2and we also have sensors for leaf temperature,” adds Rhydian. “It can be used to validate production metrics for any crop species of interest, along with associated metrics such as microbial load and energy use by system component. This allows both for information for business case planning and for ongoing optimisation.”

As indoor farming expands, facilities such as these are becoming more pertinent. One criticism levelled at indoor farming is the energy cost involved, and there is little hard data available on this. “Proponents of controlled environment growing would say you can control the environment more than you can in a glasshouse, while proponents of glasshouses will say the energy costs are higher and you are not utilising freely available sunlight,” points out Dr Andrew Beacham of Harper Adams University. “There is not much work on lifecycle analysis in the scientific literature.” A lot of vertical farming is linked to urban agriculture, and is said to reduce or eliminate emissions from transporting food. However one study found transport only accounts for 11 per cent of emissions in the food chain, while production accounts for 83 per cent, suggesting such benefits may be overplayed. “There have been a couple of studies modelling the GHG emissions from these systems,” adds Dr Beacham. “One suggested that a large multi-floored tower would have a much larger carbon footprint than conventional field-grown crops, but another found that a rooftop glasshouse could reduce GHG emissions compared to existing supply chains. However the same study concluded that using controlled environment production would actually increase GHG emissions. It is dependent on the exact type of vertical farming and the choice of location, but there aren’t many studies of pre-existing systems.”

Many involved in controlled environment production are wary of making comparisons between systems. Current, powered by GE, has supplied lighting and equipment to Jones Food Company (JFC), which will produce 400 to 500 tonnes of herbs each year from a ‘secret’ and fully automated warehouse near Scunthorpe in North Lincolnshire. Karen O’Neil of Current, powered by GE, comments, “It’s difficult to compare like-with-like as vertical farming reduces food miles yet has a higher energy input. Companies like JFC are reducing the carbon footprint of their facilities by using solar panels to reduce their reliance on the National Grid. It’s important to ensure that energy is used as efficiently as possible. Our horticultural lighting is among the most energy-efficient on the market and each luminaire produces less heat, therefore reducing the burden on the ventilation and air conditioning systems.”

India Langley of Bristol-based LettUs Grow, which is developing aeroponic vertical farming technology, says that, unlike traditional greenhouses, most vertical farms do not need additional heating. “Growing vertically also takes the pressure off of depleted soils without the need to create new farmland,” she adds. “Independent, academic studies into LettUs Grow’s technology have shown that our patent-pending aeroponic technology can reduce the carbon cost of production by between 60 and 90 per cent compared to traditional hydroponic vertical farms.”

Whatever the carbon footprint, reducing it is already a priority for the sector. “Energy is one of the most significant ongoing costs to the vertical farm business,” says Diane Esvan. “Reducing energy costs is therefore a priority to make the farm more profitable. By closing the gaps and bringing the racks together, our V-Farm systems utilise light more efficiently leading to less power need. Due to our moving tray system, we can also add different lights at different stages leading to power savings.”

As the scientific understanding of different light wavelengths on plants has increased, and the cost of LED lighting has fallen, previously theoretical benefits of indoor farming have become a reality. “Having independent control over most environmental variables means that you can produce ‘tailored’ plants for different markets and or applications,” points out Rhydian. “You can achieve generally greater nutrition than from conventional glasshouse and field production and you have the ability to alter the flavour profile and pigmentation of the crop.”

This has been demonstrated at Signify’s Dutch GrowWise Research Centre. “The red colouration of lettuce for example is typically a stress symptom, and so in red-leaved varieties growth is often reduced and production takes longer,” says Tom Könisser. “We have found that we can use one light recipe to grow the plant as fast as possible, and then we use a different light treatment with a higher blue percentage for the last three days, which gives an intense red colour.” Another environmental benefit of indoor farming is reduced water use. By recirculating water, V-Farm claim to use 80 per cent less than conventional agriculture. “If you compare open field production to indoor production, on average 25 litres of water is necessary per kg of lettuce in open fields whereas in an indoor farm we need 1.5 litres, so it is a huge reduction,” adds Tom.

These savings are confirmed in commercial practice. Growing Underground grows crops in a network of disused tunnels 33 metres below Clapham in London. Co-founder Richard Ballard explains that an outdoor grower would typically achieve six to ten harvests of pea shoots a year, a figure which would increase to 25 to 30 for glasshouse production in the Northern hemisphere. “In a controlled environment, such as our farm, you can obtain up to 60 harvests, with yields averaging 2.5 to 3 kg per m2per week. That works with pea shoots, but we are not there yet with some baby leaf or heads of lettuce, says Richard. The company, which was established in 2012, came from the ideas of American economist and sustainability advocate Jeremy Rifkin, who feels that local, integrated food and energy production is the only way to sustainably feed and power a growing population, 80 per cent of whom will live in cities. It supplied its first food service customers via New Covent Garden Market in 2016 and retailers in the capital since 2017.

Like many indoor farming companies, Richard and his co-founder Steven Dring did not come from a traditional farming background, but Neil Sanderson of Florette joined the board early on and G’s Fresh are key investors. “LEDs had only just come out and were quite new and like any technology when it first comes out, they weren’t very efficient,” comments Richard. “We are now getting to profitability on microgreens, and in the next three or so years you will get that with growing a head of lettuce in a controlled environment with lights.”

Needing to compete with large scale international production explains why most indoor farms have concentrated on producing high value crops with rapid cycle times, such as microgreens, shoots, herbs and some baby leaf crops. In Dundee, Intelligent Growth Solutions (IGS) is obtaining basil yields around 60kg per m2per year, twice what might be expected from a greenhouse. “Our platforms deliver Totally Controlled Environment Agriculture (TCEA) to radically reduce energy costs by up to 50 per cent and labour costs by up to 80 per cent,” explains David Farquhar, CEO of IGS. “Our systems are compatible with smart energy, and therefore can actually provide a means of supporting the national grid and encouraging the national adoption of renewable energy. The unit effectively acts as a large battery where the energy is converted into food.

“We are not growing produce for commercial sale, but are trialling several different varieties of salad and herbs to better understand how our technology can optimise produce growth. This includes testing plant/light interactions, sensor technology and understanding factors affecting yield, taste and flavour, allowing for the development of new plant varieties including those suitable for automatic harvesting systems. It will also facilitate speed breeding of conventional crops and could dramatically shorten the time to produce new varieties using conventional breeding methods.” Plans for an Advanced Plant Growth Centre (APGC) project based beside IGS at the James Hutton Institute are expected to create a global centre of excellence over the next five years.

Reducing investment costs will be vital if indoor farming is to reach its potential. “Because it’s an emerging field there are a lot of competing companies, which means that there is a low level of standardisation which could help uptake and efficiency,” says Andrew Beecham. “Standardisation could help, but I appreciate at the moment that it is very commercially competitive.”

His desire for a common approach is shared by Tom Könisser, who comments, “What you see today is that almost every indoor or vertical farm is unique. There is no standard and technologies are being developed each time. We believe that if you start standardising and integrating technologies then costs can come down.”

Indoor Farming, Vertical Farming and Urban Agriculture

Vertical farming may or may not use artificial lighting and grows plants both horizontally and vertically. This is usually achieved either by layering production units on top of each other or using containers with plants grown from the sides. Vertical farming systems can be a way of increasing the productivity of conventional greenhouses.

Indoor Farming (and Controlled Environment Farming) differs from conventional protected horticulture by growing plants in completely controlled and closed conditions, which requires artificial lighting, in warehouses, underground tunnels, or other structures.

Urban Agriculture is often associated with both techniques and is the idea of producing food close to populations of consumers, for example in vacant buildings or in rooftop greenhouses.