Recently, the magazine, Inc., published an article about the Source Hydropanel manufactured by Zero Mass Water. A sidebar in the article said the device produces 5 litres per day of clean water and that the cost for each panel is USD 2000. A link to the article was posted on LinkedIn. A LinkedIn member wondered what would be the "levelized" cost of water per gallon. This blog post shows one method for answering the question. The spreadsheet shows that direct capital cost is only part of the equation. But, for a quick analysis let us proceed with the bare bones information in the Inc. article.

For a 10 year equipment lifetime, cost of water (USD) is $0.41 per gallon. For 15 years it is $0.28 per gallon and for 20 years it is $0.21 per gallon. 

Today, I learned about Aalto University's Water Scarcity Atlas from The Water Network. The atlas is a useful and credible resource for learning about various aspects of the water supply challenges facing humanity. For those of us in the water-from-air community it is definitely worth visiting and bookmarking. The atlas is a useful guide to the regions on which to focus water-from-air research and development efforts.The data & code section of the atlas website had a link to the City Water Map Initiative whose data source was

McDonald and others (2014). Water on an urban planet: Urbanization and the reach of urban water infrastructure. Global Environmental Change 27, 96–105.

This paper gives the results of the first global survey of the water sources for the world's largest cities. Table 2 in the paper lists the largest cities enduring water stress. The cities (in order of population) are Tokyo, Delhi, Mexico City, Shanghai, Beijing, Kolkata, Karachi, Los Angeles, Rio de Janeiro, Moscow, Istanbul, Shenzhen, Chongqing, Lima, London (UK), Wuhan, Tianjin, Chennai, Bengaluru, and Hyderabad.

Enjoy watching our 4 minute 40 second video presentation about using mechanical dehumidification technology for obtaining drinking water from the water vapour in the air. To access the video, just click on the image above.

Chemical & Engineering News published an interesting article about drinking-water-from-air technologies which may be accessed at ​by clicking on the page excerpt image above.

The September 28, 2018 earthquake and tsunami disaster in Palu has caused shortages of clean water (see for example, "Palu earthquake, tsunami victims get clean water support", The Jakarta Post). The Water-from-Air Resource Chart for Palu is a free download.  

This article is a nice up-to-date review about water-from-air technologies. Tim Smedley, the writer, interviewed me about some of the information that appears in the article. You can find the online article by clicking on the image above.

​For blog readers who may relish a scientific conference about water—The Welch Foundation Conference on Chemical Research  "Water: Science and Technology" will take place in Houston, TX October 22-23, 2018. I am going! You can learn more about the conference at http://www.welch1.org/conference/conference-program —be warned— the experience will likely be similar to attending university lectures in chemistry and physics!

In response to a reader's comments, the July 2018 reprinted second edition incorporates enhanced temperature versus relative humidity psychrometric tables in Chapter 4 with wider temperature ranges (0–55 °C; 32–132 °F) for finding water vapour density, humidity ratio, and dew-point. This makes the tables more useful for cities like Abu Dhabi, Doha, and Dubai.

This reprint also has a revised Appendix 6: Economics of Off-grid Solar PV for WFA. There are two detailed examples in the Appendix. The first example is for a 1.05 kW input power atmospheric water generator using 1-phase electric power. The second example is for a 2.1 kW input power atmospheric water generator using 3-phase electric power.The Appendix presents clear diagrams showing the main components of single-phase and three-phase off-grid solar PV systems. The Appendix concludes by revealing, for each example, the ratio comparing the price of an off-grid solar PV system to the price of the atmospheric water generator.

The Water-from-Air Quick Guide may be purchased from Amazon. 

Did you know LinkedIn has a group devoted to the topic of Atmospheric Water Generators? It has 50 members at this time. The Group Owner is Stuart Shapiro, EVP at Infinite Water, Inc.

I encourage anyone interested in the water-from-air field to join the group and contribute to discussions relevant to AWG technologies.

Five new products, of interest to professionals involved with pyschrometrics, meteorology, HVAC, dehumidification, and water-from-air systems (atmospheric water generators) have been added to the category, "Tables" in the Atmoswater Research online store:

• Humidity Ratio Table
• Specific Humidity Table
• Atmospheric Water Vapour Density Table
• Dew-point Table
• Bundle (set) of all four tables

The tables are for the dry bulb temperature range 0–55 °C (in steps of 1 °C) and relative humidity range 0–100 % (in steps of 10%).

Our Privacy Policy was updated.

Moscow and London among the cities that could run out of drinking water? Yes, according to a BBC report in February 2018.

Moscow's drinking water comes mostly from surface water. Industrial pollution affects surface water in Russia.

London has relatively low average annual rainfall feeding the Thames and Lea rivers which supply much of London's drinking water. Capacity limits are being approached and are likely to be exceeded in the next couple of decades.

Although Moscow and London are not ideal sites for a year-round water-from-air resource, there is enough moisture in the air during the summer months to allow machines to operate.

The new Water-from-Air Resource charts for Moscow and London, now available for purchase and download at the Atmoswater Shop, will be of interest to city planners and others concerned about ensuring water security for the people living in these two cities.
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• Nature Conservancy reference 

​Thermoelectric cooling technology has had wide appeal as an alternative to mechanical refrigeration cooling technology for at least twenty years. Thermoelectric systems avoid the use of hazardous, harmful refrigerants and noisy compressors​. Low coefficient of performance (COP, in the range of 0.9–1.2) is the main problem preventing widespread use of thermoelectric cooling especially for systems requiring large cooling capacities (Riffat & Ma, 2004). A COP of 1.2151, achieved using a multistage thermoelectric module, was considered "remarkable" by Patel and others (2016)  Only smaller capacity niche applications have been commercialized.

There have been several peer-reviewed papers published and patents issued for atmospheric water generators or dehumidifiers using thermoelectric cooling devices which use the Peltier effect. Some information and products have been featured on websites. Each reference below represents a clickable link to more information.

Examples of papers

Atta, R. M. (2011). Solar Water Condensation Using Thermoelectric Coolers. International Journal of Water Resources and Arid Environments, 1(2), 142–145.

Milani, D., Abbas, A., Vassallo, A., Chiesa, M., & Bakri, D. A. (2011). Evaluation of using thermoelectric coolers in a dehumidification system to generate freshwater from ambient air. Chemical Engineering Science 66(12), 2491-2501.

Muñoz-Garcia, M. A., Moreda, G. P., Raga-Arroyo, M. P., and Marin-González, O. (2013). Water harvesting for young trees using Peltier modules powered by photovoltaic solar energy. Computers and Electronics in Agriculture 93, 60–67.

Nandy, A., Saha, S., Ganguly, S. & Chattopadhyay, S. (2014). A Project on Atmospheric Water Generator with the Concept of Peltier Effect. International Journal of Advanced Computer Research, 4, 481–486.

Suryaningsih, S. & Nurhilal, O. (2016). Optimal design of an atmospheric water generator (AWG) based on thermo-electric cooler (TEC) for drought in rural area. AIP Conference Proceedings 1712, 030009 (2016); doi: 10.1063/1.4941874

Davidson, K. B., Asiabanpour, B., & Almusaied, Z. (2017). Applying Biomimetic Principles to Thermoelectric Cooling Devices for Water Collection. Environment and Natural Resources Research 7(3), 27–35.

Examples of Patents

Peeters, J. P. and Berkbigler, L. W. 1997. Electronic household plant watering device. United States Patent 5,634,342. [expired, now in public domain]

Wold, K. F. 1997. Plant watering device and method for promoting plant growth. United States Patent 5,601,236. [expired, now in public domain]

Reidy, J. J. 2008. Thermoelectric, High Efficiency, Water Generating Device. United States Patent 7,337,615.

​Waite, R. K. & Neumann, A. (2017). Water production, filtration, and dispensing system. United States Patent 9,731,218 B2.

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Examples of Websites

The "instructables" website published the article "How to Make a Dehumidifier (Thermoelectric Cooling) in 2016.

Amazon.com sells several models of "thermoelectric portable compact dehumidifiers".
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​References

Patel, J., Patel, M., Patel, J., & Modi, H. (2016) Improvement in the COP of Thermoelectric Cooler. International Journal of Scientific & Technology Research 5(5), 73–76.
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Riffat, S. B. & Ma, X. (2004) Improving the coefficient of performance of thermoelectric cooling systems: a review. Int. J. Energy Res. 28: 753-768 (DOI:10.1002/er.991)

The target market for atmospheric water generators, in the broadest sense, are people in locations with perennial water shortages due to population growth, climate change, and lack of enough sustainable surface or groundwater within a radius of 100 km. The reference for these defining conditions is: Lalasz, R. (2011). New Study: Billions of City Dwellers in Water Shortage by 2050; retrieved from https://blog.nature.org/conservancy/2011/03/28/pnas-billions-city-urban-water-shortage-2050-nature-conservancy/. A study led by the Nature Conservancy defined these conditions. At least 23 cities fit these conditions. From north to south they are: Shenyang, Beijing, Tehran, Haifa, Tel Aviv, Jerusalem, Lahore, Delhi, Dubai, Riyadh, Abu Dhabi, Kolkata, Mexico City, Mumbai, Hyderabad, Manila, Chennai, Bengaluru, Caracas, Lagos, Cotonou, Abidjan, and Johannesburg. Some small tropical islands such as Grand Turk, Turks and Caicos Islands and Sal Island, Cabo Verde also fit these defining conditions. Recent reports such as “The 11 cities most likely to run out of drinking water - like Cape Town” by the BBC (http://www.bbc.com/news/world-42982959; 11 February 2018) suggest that we could add other cities to the Nature Conservancy’s list. From the BBC report here are nine more cities to add to the list of those likely to run out of sustainable natural water supplies: Cape Town, São Paulo, Cairo, Jakarta, Moscow, Istanbul, London, Tokyo, and Miami.Water-from-Air Resource Charts are available for all the highlighted locations mentioned in this post—just click on the location name to go to the relevant page in the Atmoswater Shop. By the way, if you like bargains, the charts for the 23 water-scarce cities listed by the Nature Conservancy are all included in the book, Water-from-Air Quick Guide.

Several new water-from-air resource charts for cities in India are now available for purchase and download at ​https://www.atmoswater.com/store/c130/India.html. The cities include Bikaner, Dhubri, Dibrugarh, Kota, Srinagar, and Trivandrum. 

​I discovered several interesting bits of knowledge about dew and dew condensers in this article by a team of dew researchers:

Here are the bits I chose to highlight:

• "…there is no standard instrument for measuring dew…";
• "…the greater the heat capacity of a condenser, the poorer the potential water yield…";
• Dew collection works best with windspeeds less than 3 m/s;
• Although dew is essentially distilled water, its chemistry is affected by substances residing on the dew collection surface;
• Stone heaps in Feodosia, Ukraine, that have been referred to in many publications as being passive dew condensers are, "…just the remains of Greek or Scythian tombs"; and
• "…radiation-cooled light condensers are presently being used in Corsica island (France), Bisevo island (Croatia), Jerusalem (Israel) and Kothara (India)…" [at the time of publication in 2006].

I have the privilege of being accepted as one of the presenters during the Technical Sessions at the 23rd Annual Caribbean Water and Wastewater Association (CWWA) Conference and Exhibition scheduled for October 6-10, 2014 at Atlantis Resorts on Paradise Island, Bahamas. Here is the Abstract of my paper:

Regional droughts in the Caribbean are common. Water managers seeking solutions to water scarcity are often unfamiliar with the option of using water-from-air technology. Maps of the specific humidity composite mean for Junes and Decembers during the ten-year period 2004–2013 quantify the water-from-air resource demonstrating it is suitable for operation of water-from-air systems in Caribbean countries. Quantitative investigations by the author found droughts and long-term climate change do not appear to affect the magnitude of the Caribbean region’s water-from-air resource. Case studies include one for a proposed water-from-air commercial greenhouse on Grand Turk. Another case is about the experience of commissioning a 2500 L/d water-from-air machine in Belize City. Lessons learned from the case studies are outlined.

Air masses with relatively high water vapor densities (exceeding 12 grams of moisture per cubic meter of moist air) surround San Francisco / San Jose and Los Angeles / San Diego. 'Good' performance is expected from water-from-air systems (atmospheric water generators) operated in these regions. Over the balance of the state, the water-from-air resource is graded as 'fair'.

This map is from the new Atmoswater Research 45-page publication, Atlas of the Water-from-Air Resource for California.

Tour Stop 8: In San Francisco, the diurnal regime of the water-from-air resource is somewhat variable with the seasons. (Click on images to enlarge them)

Abstract from my article published February 11, 2014 on Water Online:

Quantifying the water-from-air resource enables targeting selected cities where installing strategically located stand-alone processors of atmospheric water vapor will have the quickest, most beneficial impact for people facing water scarcities.