Can Solar Atmospheric Water Generators Cut Energy Costs?

Home renovation is an exciting activity that helps to cut down on energy costs. One way of doing this is by installing solar atmospheric water generators (AWGs). These generators are ideal in hot and humid areas where electricity is not readily available and water quality is poor. They extract water from humid air by harnessing the power of the sun, instead of using electricity. Using solar power is almost always less expensive than using electrical power, but the initial cost of purchasing solar technology is usually more expensive than comparable equipment that uses electricity.

There are various technologies that extract water from the air, but the most commonly used for domestic use is similar to the way air conditioners work. Warm, moisture-laden air is passed over a chilled surface medium like a plate or coil, reducing the temperature, causing condensation. In an air conditioner, the moisture is channeled to a collection dish, or drain, and the cooled air is circulated back into the room. In a water generator, the moisture is harvested and filtered repeatedly to remove bacteria and particulates. The more humid the air, the easier it is for a water generator to harvest water vapor efficiently. This cooling condensation harvesting method is popular, but it uses a lot of energy.

For small volume applications, water generators that use refrigerants as a fundamental part of the water extraction process are popular. However, for industrial and some military applications, there are water generators that use a chemical process involving special salts called desiccants. These salts absorb moisture from the air, and equipment extracts the moisture from the salt. The exact process manufacturers use is proprietary, but it usually involves boiling the salts to create steam, which is then condensed and harvested. The process can be very energy efficient when a vacuum is used in the boiling chamber, as a vacuum will lower the boiling point of water, requiring less energy to generate steam. Desiccant water generators use less energy than cooling condensation water generators, which makes them a technology to watch.

A solar water generator is cost-effective in a straight energy consumption comparison, but there are a few things to consider. Because high humidity is seasonal in many areas, water generators operate most effectively during the summer months, often when electricity is in greatest demand. Solar cells can charge in diffuse light, but perform better when the days are longer. Water generators need a relative humidity of around 40 percent or more, and a temperature of at least a few degrees above freezing to work efficiently. This means that there may be times when water generators have trouble extracting water from the air, and alternative sources of water will be necessary. If there isn’t enough light, solar water generators are often equipped with electrical backup power. They’ll use solar power when it’s available and revert to electricity when it’s not. When using electricity as a backup, the electrical power necessary to operate a water generator designed for home use is comparable to the power necessary to run a small space heater or personal computer.

Concerned About Tap Water Quality?

Before you start exploring alternative options for safer drinking water, take the time to check the current quality of your municipal water supply. You might be pleasantly surprised by what you find out. The Safe Drinking Water Act mandates that water suppliers serving over 100,000 people publish an annual report on their water quality. You can obtain a copy of the report for your area by contacting the customer service number on your water bill or by visiting the EPA’s Consumer Confidence Report Page for more information.

Additional Resources

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• How Solar-powered Refrigerators Work
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Sources

• Aqua Sciences. “Advanced Water Technology.” (10/31/11). http://www.aquasciences.com/about.html
• Atlantis Solar. “Understanding the Water Generation Process.” (10/31/11). http://atlantissolar.com/awg_process.html
• Green Energy News. “Dewpointe Atmospheric Water Generator.” 2/9/10. 10/31/11. http://www.renewable-energy-news.info/dewpointe-atmospheric-water-generator/
• Greenfieldboyce, Nell. “Water Extracted from the Air for Disaster Relief.” National Public Radio. 10/19/06. (10/31/11). http://www.npr.org/templates/story/story.php?storyId=6326050&ft=1&f=1019
• Heimbuch, Jaymi. “Buying a Water Filtration System: Determining Which System Is Best for You.” 6/3/09. 10/31/11. http://www.treehugger.com/clean-water/buying-a-water-filtration-system-determining-which-system-is-best-for-you.html
• Heimbuch, Jaymi. “The Low Down on Home Water Makers and 7 to Choose From.” TreeHugger.com. 6/22/09. 10/31/11. http://www.treehugger.com/clean-water/the-low-down-on-home-water-makers-and-7-to-choose-from.html
• Hudson, Audrey. “Making Water From Thin Air.” Wired. 10/6/06. (10/31/11). http://www.wired.com/science/discoveries/news/2006/10/71898
• Renewable Energy News “Dewpointe Atmospheric Water Generator.” YouTube.com. 2/6/10. (10/31/11). http://www.youtube.com/watch?v=jVIBxPIwW0M
• Rosen, Nick. “Magic Water Harvesting Machine.” Off-Grid. 11/15/06. (10/31/11). http://www.off-grid.net/2006/11/15/magic-water-harvesting-machine/
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• Solar Sphere. “Dolphin 1 Atmospheric Water Generator.” 10/31/11. http://www.spheralsolar.com/products/Dolphin-1-Atmospheric-Water-Generator.html
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FAQ

1. What is a solar atmospheric water generator?

A solar atmospheric water generator (AWG) is a device that uses energy from the sun to produce clean drinking water from the air. The AWG works by using a combination of condensation and filtration to extract moisture from the air, which is then turned into drinking water. This technology is particularly useful in areas where access to clean drinking water is limited, as it does not require a pre-existing water source.

2. How does a solar AWG save on energy costs?

Solar AWGs are designed to be energy-efficient, as they rely solely on the power of the sun to operate. Unlike traditional water filtration systems, which require electricity to function, a solar AWG uses solar panels to generate the energy needed to run the unit. This means that the cost of operating a solar AWG is significantly lower than that of a traditional water filtration system, making it a cost-effective solution for areas with limited access to clean drinking water.

3. What are the environmental benefits of using a solar AWG?

Using a solar AWG has a number of environmental benefits. For one, it reduces the need for bottled water, which can be harmful to the environment due to the amount of plastic waste it generates. Additionally, solar AWGs do not require a pre-existing water source, which means they do not contribute to the depletion of groundwater reserves. Finally, because solar AWGs rely on the power of the sun to operate, they do not produce greenhouse gas emissions.

4. Can a solar AWG be used in any climate?

While solar AWGs are designed to work in a range of climates, they are most effective in areas with high humidity and a lot of sunlight. This is because the more humid the air, the more water the AWG can extract from it. Additionally, the more sunlight the AWG receives, the more energy it can generate to power the unit. However, even in areas with low humidity and less sunlight, a solar AWG can still be effective, although it may produce less water overall.

5. How much does a solar AWG cost?

The cost of a solar AWG can vary depending on the size and capacity of the unit. Generally speaking, smaller units designed for personal use can cost anywhere from $500 to $2,000, while larger commercial units can cost upwards of $10,000. While the initial cost of a solar AWG may be higher than that of a traditional water filtration system, the cost savings over time can be significant, as solar AWGs do not require electricity to operate.

6. Are there any drawbacks to using a solar AWG?

One potential drawback to using a solar AWG is that it may not produce enough water to meet all of a household’s or business’s needs. Additionally, solar AWGs may require more maintenance than traditional water filtration systems, as they rely on a combination of condensation and filtration to produce clean water. Finally, in areas with low humidity or limited sunlight, a solar AWG may not be as effective as other water filtration systems.