Urban farming start-up demonstrates aquaponics, vertical growing
In the shadow of London’s Shard, Europe’s tallest skyscraper to date, Tom Webster and Kate Hofman have set up what is possibly the world’s smallest salad and fish farm: the GrowUp Box.
GrowUp, a start-up supported by Climate-KIC UK, has set up a demonstration installation on a playground off Union Street, not far from London’s financial centre. The project consists of a second-hand shipping container, with a greenhouse on top.
The installation demonstrates a unique and ultra-sustainable form of aquaponics – a farming method that combines hydroponics (growing plants in a water solution without soil) and aquaculture (fish farming) to make an efficient closed-loop system.
Wastewater from GrowUp’s fish tank is converted into nutrients by micro bacteria. The nutrients fertilise the plants and in turn the plants purify the water.
The only input into the system is fish food and a small amount of electricity to run the water and oxygen pumps.
The container-greenhouse combo produces a range of fresh salads, tomatoes and herbs, as well as Tilapia fish.
High-density, vertical growing
Unlike similar aquaponic projects, GrowUp’s plants are stacked on top of each other.
The system, built by Climate-KIC summer school alumni Kate Hofman and her plant-expert business partner Tom Webster, uses a revolutionary high-density vertical growing system, saving precious urban space.
“It is high yielding and low labour. Even this small setup – requiring one day of labour a week – produces over 500 kilos of salads and herbs per year,” says Webster, an environmental biologist with a degree in sustainable cities. In addition to salads and herbs, the GrowUp Box is also set to produce 160 kilos of fish per year.
The fourteen square-meter demonstration system was built with £16.500 (€19.300) Kickstarter funding, contributed by over 300 supporters in early 2013.
GrowUp is now investing a €20.000 Climate-KIC seed-funding grant to attract further capital in order to scale up to a full-size farm of 500 square meters.
The team is currently identifying brownfield and roof-top sites across Greater London. “We’re looking at a minimum lease of five to ten years,” Hofman said. With current market rates, the start-up would need ten years to get their return on investment.
“Normally, you pour water on top of the plant. We feed water directly to the roots of the plant. That’s the big winner,” Webster says.
GrowUp’s system uses 90% less water compared to traditional farming methods.
The demonstration project consists of a tank with 150 fish, 400 salad plants in the green house on top and a closed-loop circulation and filter system.
“We were initially just growing lettuce, but after working with the chef’s we supply we are now growing a large variety of salads to bring them the exact herbs and leaves they need,” says Webster. Grow Up’s produce is becoming a hot commodity among London’s restaurants, which currently sell it as a premium product.
Once Grow Up has scaled up to a commercial scale, however, Hofman and Webster plan to match, at most, organically grown food, rather than just servicing the top end of the market.
A full-scale 500 square-meter farm could be operated by four people and would produce three metric tons of salad a month and 600 kilos of fish.
Educating the community
Grow Up actively collaborates with the community around Union Street to provide education to school children and students.
“We have spent quite a lot of time with local schools,” says Webster. The start-up has received over 350 school children from The Cathedral School of St. Saviour and St. Mary Overie and St Joseph’s R C Primary School, giving them a first-hand crash course in sustainable farming.
Located on the Marlborough Playground, Grow Up has also been attracting attention from local youths that play ping pong and beach volleyball in the area. “First, kids come down and ask you what’s going on. Then they come back with parents and friends,” Webster says.
“At the scale of the GrowUp Box, urban farming has to be about education and community,” say both Hofman and Webster.
GrowUp is considering producing and selling additional small-scale GrowUp Box installations to fulfil requests from local community organisers, schools and companies interested in funding social and educational activities.
Grow Up has entered the first stage of Climate-KIC’s Acceleration Programme in September 2013 with a €20.000 grant. “It enables us to start producing marketing and investment material, and to work with an architect to produce CAD design drawings, all of which are vital for us to scale our business to commercial growing,” Hofman said.
Climate-KIC further supports GrowUp through a business coach to help develop their business and investment plan. Hofman and Webster regularly attend Climate-KIC master classes to develop their business skills. “Climate-KIC’s network has been extremely useful,” the team stressed.
“What’s great about Climate-KIC is that it is very specialised – unlike more broader oriented organisations. We know their priority is supporting entrepreneurs who have a focus on innovation for climate change, not just generating profit, Hofman said.
“Do something practical, don’t just talk about it. That’s something Climate-KIC really encourages”
A lean start-up
GrowUp has decided to set up their business in a non-traditional way, Hofman said: “Most people work on their business plan forever. But we decided to do the pilot straight away.”
Hofman said that while founding the company, they looked at people running impressive businesses. “What they had in common is that they just did it,” she said, pointing to the ‘lean start-up’ method taught in Climate-KIC’s entrepreneurship programme.
“Do something practical, don’t just talk about it. That’s something Climate-KIC really encourages,” Hofman concludes.