This YouTube video by the Dutch foundation, Happy With Water Foundation, reviews several atmospheric water vapour processing methods and then states that an absorption cooling method using solar energy and vacuum tubes with heat pipes reduces the energy cost of water making it relatively more affordable and practical compared to most other options.
Field trial of the AKVOS water-from-air system in January 2018 on Sal Island, Cabo Verde. The water production module is on the left and the atmospheric water vapour absorption module is on the right. Water vapour in the air is aborbed by liquid glycerol flowing on the white fabric in the metal framework. The hydrated glycerol is transferred to the water production module. Solar heat is used to evaporate water out of the glycerol. The water vapour condenses into liquid water on the bottom inside surface of the module. Photo by Roland Wahlgren.
For some time I have wanted to highlight this interesting water-from-air system. The photo shows a prototype system using glycerol as the liquid desiccant to absorb water vapour from the air on Sal Island in the eastern tropical Atlantic Ocean (17°N, 23°W). The prototype was designed and built by Dr. Pavel Lehky who holds United States Patent 9,200,434 B2 for the system. The field trials were done during Team AKVOS's participation in the Water Abundance XPRIZE competition. I was a member of the team. During a typical night at the site, the absorption module with its 9 square metres of surface area absorbed over 4 L of water. The 0.25 sq. m. production module was able to recover about 0.3 L of this during a typical day. So, one of the lessons from the trial was the water production module area has to be better matched to the capacity of the absorption module. Improving the efficiency of the water production module is also of benefit—this is a focus of ongoing design improvements. Find out more about Stiftung Sanakvo (Team AKVOS) at their website. Sanakvo also has a video on YouTube with an explanation of the system and showing the prototype operating during the field trial.
Visit the new Case Studies page to learn about practical applications of water-from-air systems!
Drinking-water Industry Organizations Links is a new page on the Atmoswater Research website. I hope people in the industry find it to be useful. Please tell me if there are other industry organizations that should be listed on this page. Thanks!
Do atmospheric water generators—producing water with low total dissolved solids (TDS)—need to incorporate a mineralization feature into their design? Reading this article by the Water Quality Association gives you the knowledge to make an informed choice or to have a useful discussion about this topic.
The Water Quality Association has a useful knowledge-base, much of it relevant to water-from-air systems, available on its Technical Fact Sheets page.
Patricia Oliver, a librarian in St. Croix, phoned me. Her library used an atmospheric water generator (AWG) and it worked very well year-round---climate conditions are ideal for operating water-from-air systems. Ms Oliver believes AWGs are much needed in St. Croix. The problem is that local firms are wary of importing machines because there are limited options for servicing the machines. If you, as a water-from-air systems supplier, would like to enter into a dialog with Ms Oliver about contributing to solutions for the drinking water supply challenges in St. Croix, please ask me for her contact details. Thank you!
The University of California, Berkley research group led by Omar M. Yaghi published recently an article in ACS Central Science describing how they built and tested a metal-organic framework water harvester prototype. The system produced fresh water at the rate of 0.7 L/day in the Mojave Desert during a 3-day trial (October 17–20, 2018). During this period the ambient air dew-point was less than 5 °C for 85% of the time.
#WaterfromAir Industry News: Jeff Szur, formerly VP of Drinkable Air, starts The Trident Water Company
You can read the update by Jeff Szur at this link: https://mailchi.mp/5b1d9c7272fb/my-new-venture?fbclid=IwAR3ZLsQGIUKDRT3lPfATLn4ATO2Shjfjs1QKXEus_9L5rZRl2N1cUL0FBt0
"Thanks Roland, I have great admiration for your website and content, a great resource!"
- comment from a new LinkedIn connection today
Are you a supplier of products to the water-from-air industry? Attract more traffic to your website and gain new sales prospects by advertising on our Suppliers Links page. This is the most visited page on our site with visitors from around the world. Faced with the list of 70 or so suppliers, people looking for water-from-air systems are a bit perplexed as to where to start their search for a reliable equipment source. It is easy to imagine they start by looking at who is advertising—advertisers have enhanced credibility.
The Atmoswater Research website requires money and time to maintain and improve the content for the benefit of the entire industry. Advertising with us and purchasing our digital goods helps provide the financial support needed for long term evolution. A big thank you to our customers!
Please contact Roland Wahlgren to discuss your company's plans for advertising on our site!
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:
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.
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.
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".
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.
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.
I have been researching and developing drinking-water-from-air technologies since 1984. As a physical geographer, I strive to contribute an accurate, scientific point-of-view to the field.