I love writing about food, sustainability, and urban agriculture.
What Makes These Design Examples So Great?
What do you think of when you hear the phrase "sustainable design"? Do you maybe picture hybrid cars or artsy modern green buildings?
The best examples of sustainable design, I believe, are products that are above all simple and purposeful. Simple, in that they use basic natural laws and principles and are cheap to make. (So we're not talking nanotechnology, for example.) Sustainability is not just about preserving the environment, it's also about meeting human needs.
There's a lot of interest when it comes to "sustainable design" in figuring out how we can still build our big homes and drive our cars without a guilty eco-conscience—the rich have the money to invest in that. But designs that help the poor meet their needs must be cheap and simple if they are to be perpetuated.
3 Remarkable Sustainable Designs
I want to highlight three sustainable designs that both serve an important human need and help to lower our footprint on the earth. And they're simple—two of them technically can be made and used in your backyard!
- The Peepoo Bag
- Recirculating Aquaponics
- Solar Cooking
1. The Peepoo Bag
The Peepoo bag is a great example of a simple sustainable design, serving a highly important need. (And it's okay to laugh at the name!) Created by the Swedish group Peepoople, the bag aims to solve water contamination issues in slums and disaster-hit areas of the developing world. The World Health Organization claims that about 40% of the world population does not have access to a toilet. One child dies every 15 seconds from water contamination, and this is largely due to human waste contaminating the water supply.
The bag has a large contingent of possible users: In 2003, the UN calculated that slums made up one third of the world's urban population. In slums, plumbing and sanitation are nonexistent, and human waste leaches into the drinking water, becoming a huge health hazard. The bag has so far been used in Kibera, which is located outside of Nairobi and is one of the largest slums in the world, and in Haiti after the 2010 earthquake when sanitation infrastructure was interrupted.
The Peepoo is a slim, biodegradable plastic bag with an inner lining made of urea. The bag is made for a single use—one defecation and/or pee—and then it's knotted at the top and disposed of, preferably offsite in containment. Urea is the main ingredient in modern synthetic fertilizer, and it speeds up the breakdown of the feces or urine into ammonia and carbonate. Effectively, in 2–4 weeks, the bag decomposes and hygienizes the human waste to the point that it is no longer a health threat; in fact, the waste can then be used as a fertilizer!
Peepoople is also looking to promote urban agriculture in slums using the Peepoo-made fertilizer, possibly turning what was once a severe problem into an asset.
2. Recirculating Aquaponics
It’s not often appreciated just how much thought goes into the design of sustainable farms. A farmer looks at her/his operation as one big ecosystem, in which each piece serves multiple purposes to maximize profit and eliminate waste. Aquaponics is the raising of fish (aquaculture) and plants (hydroponics) together in tanks of water. Essentially, it mimics aquatic systems found in nature—but okay, we'll say we "designed" it.
Wild fish stocks are being rapidly depleted. Oceans are fished at unsustainable rates, to the point that some scientists think certain populations won’t ever recover. Now half of the fish we buy in the grocery store is farmed, and these farms can pose their own environmental hazards.
The design can vary somewhat. In the photo above, you can see that in the Growing Power system the plants and fish tanks are separated and the water is circulated between them. In the floating raft system shown below, the plants are right on top of the fish tank.
The cycle works the same in each design: The fish poop, it sinks to the bottom, and the water is pumped through a second tank holding gravel or another such medium. Bacteria hang out in the gravel and break down the fish waste into a useable form of nitrogen. The water is then 'recirculated' back into the top of the tank (or a separate tank) where the plants absorb the nitrogenous fertilizer. Excess waste can be funneled out and applied to terrestrial crops or other plants in the greenhouse.
When the system works perfectly, it should require only fish feed and some form of energy for the pump. Very minimal amounts of water are lost to evaporation.
If the aquaponics tank is located in a greenhouse, the water serves an extra service as “thermal mass.” Water holds heat better than air, so at night when outdoor temperatures drop, the water retains heat from the day longer and releases it slowly, mitigating nightly temperatures in the greenhouse.
See more aquaponic designs and learn how to build a system yourself at Backyard Aquaponics!
3. Solar Cooker
These cookers are mainly promoted for use in developing countries, but some people like to use them in their backyard for a little cookout. Solar Cookers International is a small non-profit based in Sacramento dedicated to bringing solar cooker technology to rural developing world areas. See their informative National Geographic video below.
In the developing world, indoor air pollution is a bigger problem for people’s health than outdoor, because they use fires to cook and the soot and smoke gets in their lungs. The World Health Organization has estimated this pollution leads to the deaths of 2 million women and children each year. The use of wood for kitchen fires also creates a local deforestation problem, decimating animal habitats and other ecosystem functions. People (usually women and girls) have to walk farther and farther each day to gather wood, taking time away from school or other economic activities.
This has to be the simplest concept out of the three, although like aquaponics, it comes in various designs. Solar Cookers International says they make one that costs $5 and will last two years.
Shiny metal—literally aluminum foil—directs sunlight into a dark pot or box, which absorbs the energy and turns it into heat. (Dark colors are more effective at converting UV rays to heat than light colors.) A glass covering over the box may be used to create a greenhouse effect; sunlight can penetrate in, but the glass keeps the heat from escaping out. And it gets sizzling enough to cook anything—meat, bread, rice, and more! It can also boil water, effectively decontaminating it of certain pathogens.
On Amazon, a solar cooker costs about $250, but I also found directions on how to build your own solar cooker using just foil and cardboard!
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Kristen Howe from Northeast Ohio on May 30, 2015:
Tara, this was a great hub about sustainable living. Everyone should consider it and give it a try. Voted up for interesting!
Tara McNerney (author) from Washington, DC on April 01, 2012:
Thanks phdast7! I'm so glad you found it interesting - I do too, so I definitely plan on writing more on the topic! =) What great questions too. The Peepoo bag costs just a few cents per bag, which for the world's poorest is still too expensive. Oxfam is one of the most notable distributors of the bag - I know they were the group that took it to Haiti. I hadn't found anything about WHO promoting it...but you would think that would be a logical connection. Also, one idea Peepoople had for funding bag distribution would be to sell the bags in outdoor shops for backpackers and campers! They would sell it at a much higher price and use the profits to distribute it for free to the poor. You're definitely right that there are cultural barriers to be overcome. They've done surveys in areas where it's been used and find that if they can get the women of the household to promote it then their children will use it and men will eventually follow.
As for recirculating aquaponics - the movement seems to really be made of small urban farmers, nonprofits and groups like the Recirculating Farms Coalition. However, I know they're working right now at the USDA on developing an organic standard for seafood, and there's been interest in requiring certified organic operations to be recirculating farms - because they're so much better for the environment than other types of aquaculture.
Thanks so much for your questions! And thanks for passing it along! =)
Theresa Ast from Atlanta, Georgia on March 29, 2012:
What incredibly useful and much-needed inventions/designs. You write very well and your descriptions and explanations are excellent. But I want to know more. Maybe another Hub, or two or three? :)
Prices/costs for the peepoo bag? Are there any American philanthropists - Bill and Melina Gates for example - who are supporting this financially? Are there cultural or religious barriers that would make people reluctant to utilize the bag? What does the World Health Organization think and are they supporting its distribution? Who in the US is supporting and increasing our use of aquaponics? Is anyone lobbying congress to get the "BIG OIL" subsidies (how ridiculous and criminal) switched over to support aquaponics in the US?
Questions keep coming, but I am making myself stop for now. :) Great Hub. Looking forward to many more in the future. WELCOME to HubPages and SHARING this with my followers. :)
Simone Haruko Smith from San Francisco on March 29, 2012:
Whooooah! I had never heard of recirculating aquaponics before! That's the coolest thing. Peepoo bags are also entirely new to me. I love the idea, but am not quite sure how the whole pooing into a bag thing goes. Hahaa- I'd practice, but I don't think that would be a very good idea. Still, the concept is brilliant! Lovev the overview. Thanks for introducing me to some cool, exciting designs!