It’s proving to be a week of green firsts for London. Yesterday, the capital announced that it will be trialing the world’s first purpose-built, solely electric double-decker bus later this year. Now, entrepreneurs are happy to boast that the city’s underground farm, the only one in existence of course, is about to start trading.

Urban farms are not a new thing, but we’re talking about much more than just an area of a city devoted to agriculture, like rooftop farms or massive greenhouses. The £1 million ($1.58 million) subterranean site, funded mostly by the public, has taken 18 months of research and development to come to fruition. The brains behind the project are entrepreneurs Richard Ballard and Steven Dring, and famous chef Michel Roux Jr.

Located 33 meters (108 feet) beneath the Clapham area, the farm – called Growing Underground – consists of a sealed room fitted with sophisticated hydroponic systems, which allow the growth of plants without soil, a customized ventilation system and low-energy LEDs for lighting. Because the irrigation system is closed-loop, whereby the 18 cubic meters of nutrient-rich water necessary for crop growth are recycled on site, the company claims to require 70% less water than traditional open-field farming. Furthermore, this has the added benefit of zero run-off, which can cause problems for ecosystems surrounding farmland.

There are a whole host of other benefits to this style of farming, too: The crops are not subjected to unpredictable weather, there are no seasons so production can continue year-round, and the complete lack of pests and weeds means the plants don’t need to be drenched in chemicals. And by supplying to local buyers, the produce doesn’t need to travel far, slashing food miles and therefore further energy demands. Ultimately, the company hopes to become carbon neutral.

You may be aware that it is not a new concept to use urban spaces in this way – vertical farms that cram vast amounts of crops into small spaces have been around for a while. But it seems that this is the first urban farm to go underground. And they didn’t need to tunnel under the city to build it, either, as they made use of a disused World War II bomb shelter.

The produce is likely not going to come cheap, but with climate change and the availability of high-quality agricultural land representing ongoing issues, it’s encouraging to see that people are investing in innovative ways to get around these problems. Perhaps other cities with spare underground areas will take a leaf out of this book and follow suit.

[Via Growing Underground and FG Insight]