In the last post, we looked at what the idea on an eco-city was, and how energy and resource generation and consumption have a big role in an eco-city’s design. Vertical farms play a role in both of those aspects, both as generators and as users of those assets. The next point of consideration is the quality of those resources – mainly food, air and water.
Some of the issues experienced by people are the abundance of chemicals that are present in the food we consume, the water we drink, and the air we breathe. These chemicals come from vehicle and industrial emissions, herbicide and pesticide leaching, hormone and antibiotic contamination, etc. An eco-city can potentially work toward eliminating most of those chemical sources.
Because vertical farming can be done in environmentally controlled conditions, the presence of unwanted plant species, pathogens and pest are greatly mitigated. In theory, the only plants growing are the ones the farm has planted, so there is no need for herbicides. Any diseases or pests present in the crop can be caught early thanks to the technological systems, and problematic plants can be individually removed, thus removing the need for pesticides.
The same applies to any meat produce – depending on the livestock of choice, like crickets, for example, a large amount of meat protein can be grown in a short space of time, hopefully removing the use of growth hormones, and the controlled environments hopefully allow the animals to be reared in healthy conditions, with a little as possible antibiotics required.
If an eco-city’s vertical farms are producing clean, chemical-free food, this benefits the entire community consuming that produce, leaving people healthier and happier. It also makes the next aspect easier.
Water is a premium resource, and in a city, there is a lot of demand for it too. Water for drinking, water for washing, water for food production and water for sewerage. A key value of an eco-city is efficient resource use, and this is particularly applicable to water. One way an eco-city can achieve that with water is for water to be recycled. Greywater and processed sewerage water supply the vertical farm’s water demands, which in turn becomes food, which is eaten by people, and then goes back into the system as waste. Because chemicals are passed out of the human body through our waste, it’s important to reduce the number of chemicals that are going around in that system. This is partially achieved through food production, as mentioned above, and partially through how the water is cleaned too – the city’s green spaces, like parks, could act like large filtering systems, cleaning water as it makes its way through the soil, something which is achieved with greater ease when there are fewer chemicals.
As for air quality, this is achieved on two fronts – the first being to produce less pollution, by switching to electrical transport and clean energy production, and the second being how the existing pollution is recaptured – farmland that has been freed up by switching to vertical farms is returned to a forested state, acting as a pollution sink.
Another way of achieving this would be through plant covered buildings, like the one seen above. These ‘Green Buildings’ would not only absorb CO2 but would produce Oxygen. While I’m not sure of the scale, a large building could absorb 25 tons of CO2 each year, and produce 25 kilograms of oxygen each day. Imagine the clean air these cities would have.
Another thing that comes with modern human habitation and something that is concentrated in cities is waste. Food scraps, plastic and cardboard packaging, glass and metal containers, just to name a few. Unfortunately, for many cities around the world, all of that waste ends up in landfills, where it will sit for hundreds of years decomposing if it decomposes at all and leaching chemicals into the soil under which it is buried. Like air quality, there is a two-fold approach to how we solve this.
The Waste we Produce
The first approach is by changing what waste we produce. Even if you changed nothing about how we currently dispose of waste, you could still have a huge environmental impact by changing what the waste is. If all of our current plastic waste was replaced with biodegradable alternatives, a landfill’s contents would decompose in decades instead of centuries and would leach nutrients into the soil, instead of chemicals.
How we Recycle it
As good as biodegradable packaging is, an eco-city can still do one better, by changing how its waste is processed. Returning to the idea of an ecosystem, if our waste goes into a landfill, then resources have left the system. If however, the waste is recycled and returned to the system, then the potential of the waste is reused, to create new resources.
In the video above, you can see the efforts San Francisco is going to in order to become a zero-waste city. What does this mean? A zero-waste city would be a city whereas little waste as is possible goes to landfills or incinerators. The cities waste is sorted by the residents into three categories – recyclables, compostables, and landfill. Recyclable goods, such as glass bottles, could initially be sterilised and reused, perhaps holding a product a dozen times before its condition worsens beyond reuse. At that point, it can still be ground up and turned into other goods. Compostable goods, like food scraps, plant trimmings and biodegradable packaging can all be turned into compost, which in turn could supply the city’s vertical farms with more plant food for their crops. Over time, I’d like to think that the landfill category would be phased out, as all waste goods are either recycled or composted.
A Smart City
The final key to the eco-city is tying all of its parts together. Having smart vertical farms, smart transport networks, smart energy grids and smart services are all good on their own, but they all become even more powerful when they start working together. The city intelligently knows how many people reside within it. It knows how much energy, food and water is being produced and knows where to distribute it. The transport system dynamically routes itself based on the transport demands at any one time, automatically catering for peak hours or clearing a path for emergency services. It knows how well its students are performing academically, automatically referring struggling individuals extra assistance. It knows which people are sick, and even what they are sick with, automatically quarantining portions of the city if needed, or providing medical facilities with extra resources when they need it. While this idea may not appeal to everyone, the city becomes this self-aware ecosystem, that balances its needs as perfectly as it can, providing each one of its residents with all of their requirements. From that efficiency comes sustainability, something which is desperately needed.