Atmoswater Research Blog by Roland Wahlgren

#CAdrought: What does the #water vapor density field for #California look like in August?

30/7/2014

Picture of water vapor denisty field for California in August.

August water vapour density field for California. Basis for image provided by the NOAA/ESRL Physical Sciences Division, Boulder, Colorado from their web site at http://www.esrl.noaa.gov/psd/; NCEP Reanalysis dataset (Kalnay, E. and Coauthors, 1996). Click on image to enlarge.

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.

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#CaDrought and the Water-from-Air System Hourly Analysis Model

6/3/2014

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A Water-from-Air System Hourly Analysis Model for San Francisco, California is available as a free download on the Atmoswater Research website. During the prevailing California Drought, seventeen rural communities were identified by the California Department of Public Health as having "drinking water systems at greatest risk". Two of the affected counties, Sonoma and Santa Cruz are adjacent north and south respectively to San Francisco. Therefore, it is interesting to take a tour through the San Francisco hourly analysis model to see what it can tell us about the feasibility of using water-from-air machines (atmospheric water generators) as alternative or additional water resources in drought affected communities in Sonoma and Santa Cruz.

Tour Stop 1

Water-from-Air System Hourly Analysis Model (cover)

Tour Stop 1: Input values include the water-from-air machine's water production rate at a specific combination of temperature and relative humidity. The chilled surface temperature is also used as a model input value. (Click to enlarge)

Tour Stop 2

Tour Stop 2: Daily Water Production graph with an interpretation of the modeled result, (Click to enlarge)

Tour Stop 3

Tour Stop 3: Daily Average Water Production by Month with an interpretation of the modeled result. In a water crisis situation, each person needs 5 L/day of drinking water. Total daily water demand per person to take care of their drinking, cooking, sanitation, and bathing needs is typically 50 L/day. (Click to enlarge)

Tour Stop 4

Hourly Water Production Rate Annual Frequency Distribution

Tour Stop 4: Hourly Production Rate Annual Frequency Distribution with an interpretation of the modeled result. (Click to enlarge)

Tour Stop 5

Tour Stop 5: With an average daily water production of 703 L/d, one machine could serve 14 people at the 50 L/d level or 140 people at the minimal 5 L/d level of drinking water consumption. Water storage is needed to distribute the annual water production evenly over the year. Several machines can be distributed throughout a region to serve larger populations. Water-from-air is a unique decentralized way of obtaining water. It is not absolutely necessary to think of a central water production hub. The machines can be placed where they are needed.

Tour Stop 6

Tour Stop 6: The core of the model with hourly input and output values. (Click to enlarge)

Tour Stop 7

Tour Stop 7: This is an excerpt from the daily water production table that is generated from the hourly weather data. The hourly air temperature, relative humidity, and air pressure values enabled calculation of the hourly water vapour density (the water resource).

Tour Stop 8

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)

I hope you found this tour interesting! The entire model output consists of 120 pages. Becoming familiar with how a water-from-air machine responds with its freshwater production to the hourly weather at a site is a unique experience that really helps make sound decisions about whether or not to use these machines in various drought situations.

The San Francisco model shown here used weather data from 1993 because that was available as a free sample from a weather data vendor. Given the realities of climate change it would be interesting to run the model with 2013 data.

I can run models for key drought locations in California. The price per model run report is [ask for quote] (USD). Please allow up to five business days for delivery as a PDF download.

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California is a net importer of water—can water-from-air help?

18/12/2012

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A recent report by the Pacific Institute was discussed by Andrew Herndon in a recent Bloomberg article. California's 20 trillion US gallons water footprint divides up as follows:
- 90% associated with agricultural, meat, and dairy products
- 4% household use
- 3% associated with clothing and electronics production

As water-scarcity intensifies in California, use of the water-from-air resource may become economically feasible for households and manufacturing that consume relatively small daily water volumes. Atmoswater Research has water-from-air resource charts available for Los Angeles, San Diego, and San Francisco.

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#CAdrought: What does the #water vapor density field for #California look like in August?

#CaDrought and the Water-from-Air System Hourly Analysis Model

California is a net importer of water—can water-from-air help?

Roland Wahlgren

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