Atmospheric Water Generators: abundant atmospheric air to solve drinking water global challenge
According to UNICEF, WHO International, one in three people globally, does not have access to safe drinking water. As the world population is forecasted to overgrow by 2 billion people in 2050 and an additional 1.2 billion in 2100, unfortunately, this global challenge resulting from population growth is expected to accelerate within the upcoming years. This challenge exists due to other influencers resulting from unmitigated climate change impacts' risks as well as adverse effects on populations inhabiting at or near various fronts of heated conflicts around the world. Confronting this water challenge requires innovative, practical and scalable solutions that can be easily deployed anywhere with limited hurdles, that can provide instant access to safe renewable drinking water.
One of the most abundant and readily accessible; but overlooked, resources for water on Earth is the water vapour existing naturally in the Troposphere layer. The Troposphere layer contains 70 to 80 per cent of the total mass of the Earth's atmosphere and 99 per cent of the water vapour. Over the last two decades; new methodology started to emerge, bringing attention to this deserted resource; i.e. atmospheric water vapour. This technology is a descendant from a traditional method used by ancient South American Inca Empire for collecting dew using "Fog Fences" (Figure 1). The main limitation of this conventional method is that it has been entirely passive.
Figure 1 - Example of a Conventional Fog Fence.
Modern Atmospheric Water Generators (AWGs); started to emerge, offering non-passive means to extract water vapour from atmospheric air and treating it to drinking water quality levels. This pivoting change attracted attention to the possibility of replacing the traditional reliance on abundant and/or energy-intensive water resources such as groundwater, glacier masses, rainwater as well as seawater; that may always not be readily available or feasible. This pivoting change attracted attention to the possibility of replacing the traditional reliance on abundant and/or energy-intensive water resources such as groundwater, glacier masses, rainwater as well as seawater; that may always not be readily available or feasible.
AWGs emerging technologies have two primary operating principles:
- Condensing moisture when air passes over a cold surface, similar to the regular home dehumidifier principle.
- Using wet or solid desiccants to pull moisture from the air
After extracting moisture from the air, these apparatuses convert moisture to clean drinking water via several post-extraction stages of processing, filtration, disinfection and mineralization. Numerous medium-to-large scale Atmospheric Water Generators with water production above 50 litres/day are available in the market today. Small scale systems with water production below 50 litres/day are slowly emerging, enabling decentralized high-quality drinking water supply.
Innovative decentralized AWGs disrupting drinking water supply business
Even though centralized AWG systems have the ability of high productivity beyond the 50 litres/day barrier; they have various constraints that may affect their rate of deployment globally. These constraints include:
- increased CAPEX and OPEX costs;
- reliance on the availability of a reliable source of energy (Electricity primarily);
- longer lead time for manufacturing, shipping, setup and operation.
- Production in most of these systems decreases significantly at relative humidity levels below 25%;
- requiring specialized expertise for installation, testing and commissioning as well as operation;
- increasing the production capacity of existing facilities comes with significant CAPEX; and
- the long lead time of deployment makes these systems unattractive in disasters and quick relief situations.
To overcome those constraints associated with large capacity, centralized AWG systems; small-scale AWG systems with generation capacities below 50 L/days, started to emerge with the vision of making high-quality drinking water easily accessible to everyone everywhere. By simulating the microgrid concept for distributed power generation, those new innovative solutions offer almost unlimited flexibility for high quality and healthy drinking water generation, as well as disruptively changing the idea of drinking water sourcing and ownership.
The compact size and modularity of these new AWGs make them perfect for a wide range of needs, capacities and different conditions of use, where centralized large AWG systems fall back from fulfilling the job or pose various challenges for deployment. These small AWGs are characterized with their small sizes (nominally less than one square-meter of footprint area) as well as scalability to match any generation capacities needed to serve any application. Additionally, these small systems; due to their low energy demand associated with lower production; offer higher chances for being independently fed from renewable energy sources, giving it independence from any conventional sources of energy.
A more in-depth look into Zero Mass Water's innovative Small-scale AWGs working principle
Arizona-based innovative start-up company; Zero Mass Water, with the vision of "drinking water for every person everywhere", has innovated a small-scale AWG (SOURCE Hydropanels®), as seen in Figure 2, which is a fully stand-alone solar-powered.
Figure 2 - Hydropanel
Those small scales with an average monthly production of high-quality, healthy drinking water of around 120 liters, is able to extract air moisture at very low relative humidity levels near 8%. This break-through performance is attributed to the engineered, science-backed and patented process that ensures uninterruptable production at almost any weather conditions as well as providing the safety of the produced drinking water for the users.
Below is an outline of how this innovation works:
- Solar-powered fans pull he moist surrounding air and pass it through the air filter for dust particles removal.
- Subsequently, the filtered air moisture content is absorbed using proprietary hygroscopic material (desiccant); turning it into a moist desiccant.
- Dry air is utilized as a regenerative fluid, that is brought in contact with the moist desiccant inside a special compartment, releasing the moisture and regenerating the desiccant to be ready for the next cycle.
- Integrated solar thermal collectors have engineered to heat-up the regenerative fluid, resulting in an improved regeneration process.
- The moisture-laden regeneration fluid then passes through a condenser, where water vapour is condensed and captured in a built-in reservoir.
- The collected condensated water is mineralized with magnesium and calcium for optimal health and taste profile and stored within an integrated 30L reservoir. A continuous ozonation cycle is utilized to disinfect the collection reservoir and ensure that it is both viruses- and bacteria-free at all times.
- The unit is fully controlled and monitored in real-time using advanced battery-backed PLC.
- The whole process devices, such as fans and pumps, are fed from integrated solar photovoltaic panels on the top surface of the AWG compartment.
One of the Earth's near future challenges in the next decade or two, without a doubt, will be access to affordable, safe and healthy drinking water by every human being, regardless of her/his location around the globe.
To overrun such major challenge; science will need to come up with disruptive innovations to tackle this life-threatening global challenge. Innovations like SOURCE Hydropanel® are only a first step in the thousand-mile water journey. More innovations and developments are discerning in the horizon, to offer more flexibility, efficiency and easier access to safe drinking water, without jeopardizing the socio-economic-environmental sustainability bottom-line.
With the abundance of air moisture resource in our Earth's atmosphere and the technological uprise around the globe; coming up with more innovative AWG solutions that can close the current water demand gap is inevitable.
 Max Roser, Hannah Ritchie and Esteban Ortiz-Ospina (2019) - "World Population Growth". Published online at OurWorldInData.org.
Retrieved from: 'https://ourworldindata.org/world-population-growth' [Online Resource]
 Weather Facts - "Troposphere". Published online at weatheronline.co.uk.
Retrieved from:' https://www.weatheronline.co.uk/reports/wxfacts/Troposphere.htm' [Online Resource]
 'Hydropanels: Using solar to deliver drinking water from ambient air', MASDAR Technology Journal, 3 (2018), 8-10