Picture this: it’s Christmas. You drive to the supermarket to pick up the last few things. There’s gingerbread, chocolate Santas, mulled wine. And fresh strawberries. Not imported from abroad, but grown and harvested ten kilometres away. Not eye-wateringly expensive, but as affordable as in summer. And yes, they taste as if they’ve just come off the field, only these strawberries are also pesticide-free. Sounds surreal? If the founders of SymBiotic Green Technologies, Alexander and Andreas Zillinger, have their way, it could be reality within just a few years. Their technology, they believe, will redefine agriculture.
A few years ago, vertical farming was the industry’s darling. Since then, the buzz has faded. And this piece isn’t about vertical farming anyway; it’s about gravity farming. To understand what that means, it helps to look at what holds vertical farming back. “Most vertical-farming systems are closed environments, buildings where you can control every parameter,” says CEO Alexander Zillinger. “That’s also known as CEA: Controlled Environment Agriculture.” Many systems are highly water-efficient, but two key factors make them inefficient compared with conventional farming: energy costs and labour costs.
A stationary plant is a bad plant
To see why, imagine a system in which plants are stacked on shelves. Every level needs light, usually LEDs. “But no matter how efficient LEDs are, they always produce waste heat, and that heat builds up between the racks,” Zillinger explains. “The more heat you generate, the more the plants suffer from heat stress.” The result is predictable: photosynthesis shuts down and growth stalls. Fans then have to push the heat out of the system, consuming yet more electricity.
Bigger still, the Zillinger brothers argue, is the cost of human labour. “In most systems, the plant doesn’t move towards the worker; the worker moves towards the plant,” Alexander Zillinger says. “That takes time. And every level up costs more in labour than the level below.” Fully automated solutions, they add, are no silver bullet either: robots or lift systems for plant trays are simply too expensive. Andreas Zillinger is blunt: “For local farmers, or private individuals, vertical farming might be a just-for-fun project that looks nice in some lobby. But these systems don’t create real competition for agriculture. That’s exactly what we’re aiming for.”
To see how SymBiotic Green Technologies claims to solve both problems, you have to go to Gernsheim, a town near Darmstadt and home to a site of the chemicals and pharmaceuticals group Merck. Here, in the FLUXUM GreenTech Park, the Zillinger brothers have set up shop. Their technology, they say, opens up new possibilities for regional food and pharmaceutical industries, from resilient supply chains to highly precise speciality plants used in medicines.
Carp in the kitchen
SymBiotic Green Technologies began with a prototype aquaponics system. In aquaponics, fish and plants are cultivated in parallel: the fish fertilise the plants through their waste, and the plants clean the water for the fish. “While I was working in the automotive industry, I started looking closely at various vertical-farming systems as a hobby,” Alexander Zillinger says. The spark came from television. “On 3sat there was a programme called Hightech. They presented these concepts. To my wife’s great delight, I then started building a prototype with carp in our kitchen,” he says, the sarcasm unmistakable.
The early results were encouraging. “The fish did extremely well. But we quickly realised that getting the necessary licences to keep live animals would be a very time-consuming route. So we decided to focus on plant-growing systems.”
The snake winding through the room
To understand what they built next, you walk into a hall on the otherwise largely dormant grounds of the FLUXUM GreenTech Park. For two years, the brothers used this space to collect data and experience with their prototype. Today, they are assembling a new demonstrator, version 2.0.
So what, exactly, does SymBiotic Green Technologies do differently? “In our system, a conveyor belt moves the plants in a parabolic path through the space. Compared with rack systems, the growing surface is tilted by 90 degrees,” the founders explain. Hence the name: gravity farming. It looks as if the plants are growing on the wall. The design borrows from the automotive industry’s most efficient production lines. Because the conveyor moves through so-called loops at around ten centimetres per minute, much of the labour cost can be eliminated: the plants come to the workers.
That motion and the altered orientation to gravity have a second effect. The plants “think” they are about to snap, though they never do. “That releases growth hormones, and the plant grows about 30 per cent faster. You see it immediately in the yield.” The plant doesn’t just travel towards the worker; it also grows faster. Inside the towers, an arm runs along the rows and sprays the roots with water and nutrients, entirely pesticide-free. Lighting hangs between the loops. That means waste heat is no longer trapped: it rises and escapes the system.
At the same time, the usable growing area increases dramatically. “When we were still experimenting with the prototype, we had a three-metre-high system on eight square metres, with around 18 square metres of growing area and 12,000 planting slots,” Andreas Zillinger says. Depending on the crop, not every slot can be used, but the first time, he says, it still took him two weeks to fill them all. They tested basil, pak choi and strawberries. “With basil, we achieved roughly a hundred times the output per square metre compared with conventional farms.” But it’s the strawberries he talks about with particular pride. “It was an incredible experience. Strawberries are extremely demanding: warm days, cold nights. If you want yield and quality, the nutrients have to be set precisely. But from cutting to first fruit, it took us just four weeks.” That’s around 30 per cent faster growth than normal and, with two employees, harvesting 20 tonnes of strawberries a year would be possible in a factory with two growing systems. They sold the produce successfully to Michelin-starred restaurants across the Rhine-Main region.
Out of those results, they have built a demonstrator that is now being assembled in the hall. Alexander Zillinger won’t comment on the full extent of the innovation yet, as some components are currently in the patent process. What is clear is that trials are already under way with a pharmaceutical company, growing specialised plants required for medicines.
Turnkey factories
At first, Alexander and Andreas Zillinger toyed with the idea of building their own factories and selling fresh produce directly. “But we moved away from that quickly,” says Andreas Zillinger, who leads marketing and sales. Building a brand would be too expensive, money that wouldn’t go into production. “Instead, we focus on designing turnkey factories for customers and building them with our partners. If a client wants, we’ll also operate them.” With the demonstrator successfully tested, they consider the technology market-ready. “Initially, we want to start with smaller facilities, built for players in the food industry or pharmaceutical companies.” Technologically, he says, they are far ahead with the demonstrator, though specifics will only be revealed once the patents are granted. “With our expanded team, we’re also developing our own lighting solution that can save significant amounts of electricity. And we’re working on making cultivation even more efficient with AI and camera systems.” Financially, after successfully closing a pre-seed round last year, SymBiotic Green Technologies now plans to raise a bridge round via Tokenize.it, ahead of a larger round next year.
The vacuum-maker’s wheel
Towards the end of the conversation, another name comes up: Dyson. Hadn’t the vacuum cleaner company gone viral on social media with a strawberry-growing concept, and wouldn’t that make it a competitor? Alexander Zillinger waves it off. “In that concept, the plants are attached to the inside of a drum that rotates slowly. The worker still has to go to the plant. And the system is severely limited when it comes to scaling. If you want more area, you have to increase the radius. Then lighting and the weight of the components quickly become a problem.”
So the first local, affordable winter strawberries may well come from Gernsheim after all.
About Andreas and Alexander Zillinger
You might mistake them for twins. Alexander Zillinger (39) is a father of two and an industrial engineer. Alongside his work in the automotive industry, he became increasingly absorbed in vertical farming and began planning his own company. In 2017, he founded it together with his brother Andreas Zillinger (34), who has a background in marketing and sales and has since supported the venture and led day-to-day operations.
Interested?
Invest now into SymBiotic Green Technologies – completely digital and without a notary!
