A billion people could get safe drinking water from harvesting devices

[Oct 29, 2021: The Brighter Side of News]

A team of researchers from X–Alphabet's "moonshot factory," Google and the WHO/UNICEF Joint Monitoring Programme, Division of Data, Analytics, Planning and Monitoring, UNICEF, has developed a model that shows that a hypothetical device that uses solar power to pull water from the air could potentially serve a billion people across the world. In their paper published in the journal Nature, the group describes the factors that went into their model and its possible impact on the development of devices meant to meet the global challenge of providing safe drinking water to the people of the world.

As the researchers note, approximately 2.2 billion people across the globe experience challenges in obtaining safe drinking water. This, they note, is despite efforts to build desalination plants in the most heavily impacted countries. As efforts to build more plants are undertaken, another approach might be taken to fill the need in the meantime—using small portable devices that pull water from the air using solar power. The team at Alphabet was working on such a device but found it difficult to meet its goal of producing water at just one cent per liter. Recently, they made the project open-source so that others in the field can continue to build upon the work.

In building their model, the researchers acknowledged that solar powered devices capable of pulling water from the air only work well under certain conditions—where humidity levels regularly reach 30%, where there is plenty of sunshine and where it is warm enough.

To account for people living in areas with such conditions, the researchers pulled average weather data from sites across the globe and mapped them with populations facing water challenges. In doing so, they found that more than a billion people could benefit from such a device that could produce on average five liters of drinking water per day. They conclude by claiming that current technology trends suggest that the hypothetical device they envisioned in their model could soon become reality. At that point, however, it would fall to those who are able to pay for and distribute them to do so.

Real world examples of clean water producing innovations are listed below.

Some water generators, such as the WaterSeer, get a lot of hype (and a lot of skepticism) but haven't been able to deliver. Others, like the Ecoloblue devices, are a bit more costly and complex, but they actually exist and can be bought and put to work.

Zero Mass Water's SOURCE device, is a rooftop solar device that produces water instead of just electricity. The company's SOURCE hydropanel arrays are now available in the US, where "It works in almost every climate, and almost every day of the year." ... Read More

Researchers at ETH Zurich have now developed a technology that, for the first time, allows them to harvest water 24 hours around the clock, with no energy input, even under the blazing sun. The new device essentially consists of a specially coated glass pane, which both reflects solar radiation and also radiates away its own heat through the atmosphere to the outer space. It thus cools itself down to as much as 15 degrees Celsius (59 degrees Fahrenheit) below the ambient temperature. On the underside of this pane, water vapour from the air condenses into water. The process is the same as can be observed on poorly insulated windows in winter.

The scientists coated the glass with specifically designed polymer and silver layers. This special coating approach causes the pane to emit infrared radiation at a specific wavelength window to the outer space, with no absorption by the atmosphere nor reflection back onto the pane. Another key element of the device is a novel cone-shaped radiation shield. It largely deflects heat radiation from the atmosphere and shields the pane from incoming solar radiation, while allowing the device to radiate the aforementioned heat outward and thus to self-cool, fully passively.... READ MORE

Converting seawater into safe drinking water at a large scale takes an enormous amount of energy, which makes it a costly and polluting process.

Now, a Dutch-based blended finance manager Climate Fund Managers (CFM), and Solar Water Solutions are working together to develop the installation of up to 200 desalination units in Kitui County, Kenya. The project eventually aims to provide clean water made of brackish groundwater for 400,000 Kenyans by 2023.

The new solar-powered desalination system works without connecting to a grid, without any batteries or chemicals, ever. This means the system will need zero battery investments, zero running costs, have zero emissions and zero carbon footprint... READ MORE

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Tags: #Green_Good_News, #Water, #Clean_Water, #Desalination, #Developing_Countries, #The_Brighter_Side_of_News