Developing new indoor farming technologies is not just tackling a major problem but also winning awards. LettUs Grow in Bristol is developing aeroponics that allow crops such as strawberries and even trees to be grown indoors under LED lights.

The company won the Hardware Award at last week’s Sparkies for its technology, to sit alongside a number of awards and deals, including time in the Oracle and John Lewis technology incubators.

The company was set up by three engineers from the University of Bristol, where there is a focus on how to be as green as possible, says said Ben Crowther, co-founder and chief technology officer.

Being in Bristol and the strong ecosystem has been a key part of the success of the company. “We’ve got a really good ecosystem here to bounce idea off along the way,” he said.

“I’m a systems engineer and I was really interested in our food supply chain, primarily in the reduction of food waste, but then also making it more resilient to weather change and freak events to make sure we can all eat as we grow as a population and reduce the carbon footprint while doing it,” he said.

The aeroponics they developed uses 95% less water than hydroponics as it is a closed loop system based around a mist that carries water and nutrients to the roots of the plants and everything is filtered and re-used.

“Our core advantage is we have a completely novel irrigation system – our aeroponics is simple,” he said. “We don’t use high pressure nozzles that are prone to breaking, it’s a really, really simple system that we developed. That means we have increased growth rates compared to hydroponics.”

“We do use more power but the benefit is that you can position production right by the point of consumption or distribution,” he said.

“We don’t think it should replace hectares of fields. Indoor farming, greenhouses and open field farming each have their different roles,” he said. “If you can grow it in a field grow it in a field, it makes much more sense. But in many places its just not possible as it uses too much water and pesticides and the soil is degrading quite rapidly, so having a baseline production of crops that are very sensitive to environmental conditions has significant benefits.”

The company has also done a deal with renewable energy supplier Octopus Energy so that it can use cheap renewable energy, for example at night, to grow the crops. “Vertical forms will be a really important part of the electrical production grid to use the surplus renewable energy so you can use infrastructure projects to smooth out demand,” he said.

The company provides technology to people building vertical farms, and has demonstrated herbs and micro-greens which are popular with indoor farms, but can also grow strawberries and even trees.  

“We use specialist horticultural lighting and we partner with LED suppliers for that,” he said. “They are tuned for different types of crops, generally on read an blue with differing levels of green and white. We partner with a world leading researcher at the University of Bristol on circadian rhythms for plants on how we can apply this to our misting technology.”

“The John Lewis one is an interesting opportunity for future collaboration,” he said. “It’s a really exciting opportunity to work with a well known UK brand to do exciting stuff which could be in a number of areas, whether that’s in-store or otherwise.”

This is a key part of the strategy. “We are interested in supermarkets and food producers in general as vertical farming can provide a very stable rate of supply, really reliably for a low carbon cost.”

The company has also developed software called Ostara that logs all the data, automate all the irrigation and lighting schedules to reduce the labour cost and make everything as easy as possible for the farmer. “We provide insights and recipes for growth as aeroponics is a novel technology and our control hardware is tied to our core irrigation technology so we are a distributed IoT system within a confined area. We also provide cloud services such as analysis and insights to our customers – if you buy a farm from us we are invested in the growth of our customers.”

Nick Flaherty