Our article on Water Scarcity and the Namib Beetle discusses some causes of water stress and suggests we look to nature for inspiration. Let’s look at 5 sustainable options that do not require a source of power to provide water for a household’s basic daily needs.
Public Water Filter
I-Jie Tsay et al. from the National Taipei University of Education submitted this concept to both the Green Product Awards (Concept) and Golden Pin Design Awards in 2020. This gravity-fed water filter with UV sterilisation potentially removes dangerous pathogens from contaminated water. The first stage is sediment filtration, which uses local natural filter materials. Next, we open the water stop valve. Through the rotation of the manual handle, we can convert kinetic energy into electrical energy, which turns on the UV germicidal light tube. Thus, enabling the water to undergo UV sterilisation. The significant thing about this concept is it needs no external power. In rural areas without power, this concept would be vital to clean non-potable water.
Gabriele Diamanti designed this open-source project. The Eliodomestico is a solar household still. This desalination device can produce 5L of drinking water per day from saltwater and sunlight. This concept is like a coffee maker. The sun’s rays cause the saltwater to heat up. Therefore, creating a pressured steam that can only escape through an expansion nozzle that condenses on the inner walls of the lower collection container. Diamanti created this device using widely available materials, which are easy to maintain and do not require filters. Desalination is usually an energy-intensive process. Eliodomestico achieves clean drinking water with no need for electricity.
Fog Catcher, Peru
In Lima, Peru, they know Abel Cruz as the fog catcher. He uses nets to catch fog from the air. At the bottom of these nets are pipes that transport the water droplets into tanks. This method of fog catching can produce 200 to 400 litres of water per day from each net. They primarily use the water collected for agricultural practices. It is not suitable for drinking. Fog catching requires specific weather, primarily consistent fog and light winds. Additionally, the nets and tanks require a large area.
Drop By Drop
This plant-based water filtration system can purify grey-water (kitchen wastewater). The Hindi saying: ‘Drop by drop, fills an ocean’, inspired the designer Pratik Ghosh. A scaled-up version of this miniature forest could produce 160 litres of water in 12 hours of daylight. A lamp assists with photosynthesis and a pump creates a vacuum that speeds up transpiration. When the plants transpire, the moisture in the air is condesed, forming distilled water. Efficient transpiration is obtained in this biosphere by maintaining optimum levels of light, wind, humidity, and temperature.
Biomimicry and the Warka tree, a huge wild fig tree in Ethiopia, are the primary inspirations for this design. Arturo Vittori and his team designed this structure to utilise gravity, condensation, and evaporation rules. This bamboo tower with plastic lining allows dew and mist to settle in droplets. The basin at the bottom of the structure collects the water produced from the air. The canopy surrounding the structure prevents the collected water from evaporating. Standing 9 metres tall and weighing 60 kg, the Warka water structure can collect 100 litres of drinking water a day. Additionally, 100% of recycled materials are used to create this device.
Clean water for sanitary, drinking and agricultural purposes is essential. It’s great to see so many devices and concepts available for our varied needs.