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Discovering vertical power: how tech & smart energy can build a better future for farming

Centre for Net Zero   •   31 March 2022

It’s not every day that you get a unique glimpse of the future. 

Zero Carbon Farms (ZCF) has built the world’s first underground vertical farm, situated 33 metres underneath the streets of Clapham, London, in a formerly-abandoned World War II air raid shelter. 

The way this organisation grows its produce has the potential to change the way we feed our increasing global population. But whilst vertical farms present immense opportunities for the sustainable sourcing of food, they are very energy-intensive. If the agriculture industry in the United States adopted a vertical approach, the electricity required for lighting would be eight times that of the amount generated by all power plants annually across the entire country (source: Journal of Landscape Ecology 2018).

Whilst ZCF runs on 100% renewable energy, it has ambitions to improve its energy usage through smart, tech-enabled solutions. At Centre for Net Zero, we’re interested in the concept of ‘everything-as-an-energy-asset’, whereby the grid is able to benefit from energy-intensive industries participating in flexibility. We’re looking at ways that existing infrastructure in built up areas, where it’s often difficult to develop a new energy infrastructure from scratch, can be leveraged to create an optimised local system. This might involve shifting energy around from one part of a city to another: for example, a football stadium could help power local schools and houses during the day and vice versa during the evenings and weekends, when matches typically take place. 

But what is it about the way vertical farms operate that makes it so energy intensive? A few weeks ago, the team at Centre for Net Zero headed down to Clapham to find out. After a quick walk down 180 steps, we changed into hair nets and lab coats to meet sanitation requirements, and were ready to learn more.


The team sees different herbs and microgreens growing in action underground

Charlie Egerton-Warbuton, CEO and self-styled Head of Sustainable Growth, took us first to the germination tunnel, where we studied how the seeds are sown under carefully managed conditions. ZCF (which sells their produce under the brand Growing Underground) currently produces ‘microgreens’, such as pea shoots, watercress, rocket and coriander, alongside baby leaf and crops for extracts. Once seeds have spent around three days germinating in this space, they’re ready to join the farm. 

The neon-pink lit space is managed by a team of farmers who run a sophisticated lighting, irrigation and harvesting process. Crops are grown year-round in the pesticide-free environment, and the hydroponic system uses at least 70% less water than traditional open-field farming. 


Credit: Zero Carbon Farms

The results? Produce is nutritionally dense – 100 grams of their micro broccoli is 90% more nutritious in essential vitamins and minerals than a head of broccoli you might find on the shelves of your local supermarket; they have a longer shelf life, thereby reducing food waste; and they taste consistent, because of the controllable conditions. Sustainable practices are a core part of the farm’s ethos: produce is hyper-local and food miles are kept to a minimum. Most deliveries within a 5 mile radius are made by the company’s e-cargo bike or on foot, and their microgreens and leaves can reach Londoners’ kitchens within four hours of being picked and packed. 

Following the 33 metre climb back up to street level, we began to explore ways that we could help ZCF flex their energy demand to non-peak times and integrate with other generation through ‘private wire’ connections. The team are interested in the benefits of co-locating with other industries with natural synergies: for example, if the farm could sit alongside a data warehouse or a brewery, they’d be able to source excess heat and CO2 respectively. With plans to expand operations, we discussed the opportunity to benefit from an electric fleet and build out battery storage, which could help intelligently shift energy usage during different times of the day and night. 

As ZCF expands its farm and number of premises, we’ll be continuing to share ideas around ways they can optimise operations to ensure that they’re benefitting from and becoming part of the future energy system. We know that if we work together, our respective industries can work harder to deliver for both people and the planet.