Guest essay by Eric Worrall
Worried about food miles? The solution according to these greens is growing food in your basement under grow lights.
Driverless cars and climate change prompt push for urban farming
With autonomous vehicles promising to reshape buildings and even entire cities, and climate change beginning to bite, the opportunities for urban farming solutions are growing.
Five kilograms of mushrooms, 100 heads of lettuce and 25 trays of micro-greens. These are the spoils so far from Mirvac’s urban farm pilot set up in the basement of its 200 George Street HQ in Sydney.
The pilot program, Cultivate, has been operating for about six weeks, and has seen 200 staff sign up to get involved in fresh food production.
The farm includes veggie patches and hydroponic vertical farms, as well as mushrooms grown in coffee grounds diverted from landfill. Special grow lamps are used to stimulate plant growth in the basement environment.
“An urban farm could be created in a building’s redundant car park and the produce used to service local kitchens and cafes within that proximity,” JLL head of property and asset management – Australia Richard Fennell said.
I understand the urge to grow your own food, but I can’t help thinking urban farmers promoting the climate benefits of their initiative have overlooked a few details.
Running grow lights on any scale requires a stupendous amount of energy – you have to produce sunlight levels of light intensity to grow vegetables. Depending on latitude the Earth’s surface experiences up to 1000 watts per square meter of solar irradiation. While grow lights can improve on this a little, by only producing colours which are useful for plant photosynthesis, you still need a lot of energy to run a decent size bank of grow lights.
Its difficult to see how you could produce enough energy to replace millions of acres of farmland from a few wind turbines.