Crowded cities are causing problems that are going to require innovative solutions as ground breaking as anything the Victorians or 18th Century Parisians could have imagined . One of the many challenges is that as country populations increase more and more food is having to be imported from around the world. This is not only expensive and damaging to the environment, but it's also a huge waste of resources and produce, no matter how good refrigeration techniques are. As it travels thousands of miles to its destination, some of it will spoil.
One solution to this problem is to build farms in cities. A relatively new idea, the idea of farming up instead of across is gaining momentum. There are three main techniques that producers use to grow their produce in vertical farms:
1. Hydroponics, which uses a solution to grow crops rather than soil.
2. Aeroponics, where the food grows using air and mist.
3. Aquaponics, which raises vegetation alongside aquatic animals.
One of the first vertical farms was, perhaps not unsurprisingly, developed in one of the most densely populated cities in the world, Singapore. This video about SkyGreens demonstrates how a four story building in the city is providing the citizens with a rare taste of truly fresh vegetables. The racks inside the greenhouse rotate, as through they're on a big wheel, between a nutrient rich water bath and the sunshine at the top. The power comes from a gravity fed water wheel which uses the same amount of power in a month as a 60 watt lightbulb.
SkyGreens may have been a first but nothing happens in a vacuum, so in Scranton, New York, Green Spirit Farms built a vertical farm on eight acres (and average farm is 300 acres) and will produce 14 lettuce crops, spinach, kale, tomatoes, peppers, basil, and strawberries a year. This system uses rotating soil-free hyudroponics and LED's to imitate sunlight and therefore has a faster growing time than traditional methods.
What's driving this good revolution isn't just a desire for a better environment, but also that the realization that city farming is now becoming more cost effective than ever before. The technology that is used to control the environment of these buildings is improving in leaps and bounds: LED's have improved in such a way that Philips have been developing lights specifically for greenhouse farming that only use the red and blue spectrum and have become so cheap as to now be more cost effective then ever and, then there is a the sensing technology, which helps farmers minutely monitor the nutrients, water, and light levels and therefore provide the optimum conditions for individual types of fruit and vegetables.
This is still new technology and there are still only a few vertical farms around the world, but with greater energy savings and no need for soil, it's possible that they could be one answer to feeding not only the developed world but also those less fortunate where reliable quantities of fresh vegetables is a rarity.