Fog Nets 

Introduction

These rely almost entirely on the presence of frequent fog and wind, with the critical factors of the technology being the fog's density, wind speed, and the material of the mesh. The polypropylene netting collects droplets which can then gather. The combined weight of the droplets pull the water down to be collected in a tube at the bottom of the nets, which direct the water harvest into a pipes which can travel down hill to be drunk or used in farming. 

This can be ideal on desert hillslopes and other dry regions  along coastlines where fog density can be extremely high but other water sources low. Ideal placement for nets are hilltops, where gravity can bring the water into the valley for storage and use. 

Alternative Terms

This practice is also sometimes referred to as "cloud fishing".

Why Local Water Harvesting Solutions Are Important

According to a South African case study, "Small, local solutions can crack water crises"

Prevention

When we avoid overconsumption of products that consume the most water, we can have a greater, and longer-lasting impact that small, at home changes. 

Learn about which activities use the most water, to develope a plan on curring your own water footprint. In many cases consuming less will have a greater impact than harvesting water, though water collection may be your first step in your water conservation journey.

Basics of Fog Nets 

Life Expectancy

Unknown, since these are a fairly new technology. 

Benefits of Fog Nets

Passively wicks moisture from humid air. Doesn't strain surface water or aquifers. Aqualonis claims that no maintenance is needed, and that the water is safe to drink.

Problems

Won't work in dry air, may not work in still air. May have unforeseen consequences for other communities by altering atmospheric portion of the water cycle if used on a massive scale. 

Solution

Scientists should monitor what, if any impact mass implementation may have on the environment and international water cycles.

"Fuel" Types

Ambient Wind/Air Motion, Water Cycle

Guides & Practical Information

Fog harvesting: combination and comparison of different methods to maximize the collection efficiency - SN Applied SciencesFog harvesting is an unconventional source of water that can be used in some regions with water scarcity to overcome water shortages. The most commonly used collectors are meshes which have intrinsic limitations, the most important of which are clogging and aerodynamic deviation of droplets around the wires. Here, three techniques are compared and combined to overcome these limitations, i.e., replacing the mesh with an array of vertical wires, addition of a hydrophobic layer to the wires, and forcing the ionized droplets to move toward the wires by applying an electric field. The combination of these techniques was found to result in higher fog harvesting efficiency compared to each individual method with the highest impact from the addition of the electric field. The combined methods lead to a 60-fold increase in fog harvesting efficiency compared to meshes. The findings showed that when the fog droplets are forced in an electric field toward the wires, the shading coefficient for collectors can be increased to 1 from 0.55 (maximum for collectors without the electric field) without affecting the fog harvesting efficiency, allowing for lower construction cost of the collectors. Addition of the electric field showed two distinctive promotional effects. First, increasing the aerodynamic efficiency and second, reducing the size of droplets sliding down the wires by disturbing the three-phase contact line and reducing the contact angle hysteresis and the pinning force. Energy analysis shows that this technique can be 100 times more energy efficient compared to the conventional atmospheric water generators.

Similar Technology

Fog Harps

Warka Tower

Life Expectancy:  unknown

Pro: Works with passive air flow and humidity to produce potable water. Design at top helps deter birds from perching or pooping on the tower (protecting the supply), and the shade at the bottom is designed to provide a comfortable gathering spot while reducing evaporation.

Con: Relies on fog, dew, and rain.

Solution: Alternative water harvesting methods may need to be included in the community's water security plan.

Fuel Types: Water Cycle - Rain and/or aquifer water+ passive air flow + gravity.

Warka Towers "Locations with high rates of fog or humidity are the best places to install the Warka Tower. The water harvesting capacity strictly depends on the meteorological conditions and the aim is to distribute from 40 to 80 liters (10 to 20 gallons) of drinking water every day for use of the community."

"Warka Tower is designed to harvest potable water from the atmosphere (it collects rain, harvests fog and dew). It functions only by natural phenomena such us gravity, condensation & evaporation and doesn’t require electrical power. Warka Tower is designed to be owned and operated by the villagers, a key factor that will facilitate the success of the project. The tower not only provides a fundamental resource for life – water – but also creates a social place for the community, where people can gather under the shade of its canopy for education and public meetings."

System Additions

Rain Barrels/Butts & Cisterns 

These are generally used to collect rain and snowmelt, however they can also be paired with rooftop air condenser systems, to help store the water for later use. 

Life Expectancy: 20 years.

Pro: Safely stores rain or grey water for later use.

Con: An turn into a breeding ground for mosquitoes, or be contaminated with dead animals that can fall/get trapped inside. I've found dead frogs who might have hatched but not been able to get out. Dead leaves can build up, leaching tannins into the water.

Solution: Install fixtures that will help keep wildlife and leaves out of the system. Make sure to clean these to prevent plugging and backups. Empty and clean out the container periodically.

Fuel Types: Water Cycle + Gravity

Complimentary Options

Plants to Increase Permeability on Slopes

The following focus more on systems to boost soil permeability, rather than harvesting drinking or irrigation water. By sequestering water within the soil, we can (to an extent) remove the need for irrigation.

Systems such as swales double as a measure to sequester water in the soil, and when full enough, they can help transport excess water to a secondary location such as body of water, a rain garden, or regular flowerbeds.

Earthworks

Key Lines

Swales

Water Recycling 

Grey Water 

Tools & Resources

Landscaping Know-How

Organizations

Organizations

International

NGO Supplying Company

Africa

North America


Mexico

Maps

North America

USA

Grants & Funding

Oceana

Australia

Western Australia

Companies

Fog Net Producer