Novel EWA Solar Dripper 

 The Solar pipe-free dripping technology consist a novel concept for irrigation and water supply, based on extraction of air humidity drived by solar radiation. The Solar Drippers do not only save water, but also saving investment in infrastructure and water loss upon water transportation. The Solar Dripper provides water solution in places where water, or water infrastructure, is unavailable or limited.

Solar energy is available, free of charge, in more than 90% of the populated regions around the globe and during at least 80% of the year. By combining efficient utilization of solar energy with sophisticated solar chilling methods, the patented Solar Drippers provide real alternative to conventional irrigation and added value to conventional water supply.

The Solar Drippers provide an excellent solution for irrigation in regions suffering from lack in fresh water but are rich with solar radiation and high relative humidity at nighttime. The Solar Drippers constitute inexpensive system based on passive technology, which do not employ any energy source, besides the sun, and demands no maintenance.

The Solar Drippers extract the air humidity to provide fresh water. Extraction of the air moisture as an alternative water source is known and reported since Biblical time, and was applied in ancient times in the Negev desert. Various methods for extracting atmospheric moister to water were reported and applied. The most ancient of these methods make utilize of cold, others are based on condensation on cold object, such as dew, and others condense humidity by reducing air temperature below dew point. An irrigation system based on extraction of the air moisture for agricultural purposes was also documented in few scientific reports described the use of stones for condensation of air humidity at early morning hours.

The Technology

The patented Solar Dripping technology (patent application IL18373/07) is based on patented technology for solar air conditioning (patent application IL182120/07), and included a novel method, technology and apparatus for solar dropping system. The invention describes a novel concept for extraction of air humidity by utilizing methodology for cooling drived by solar Infrared radiation.

In order to condense humidity, the Solar Dripper's body needs to be significantly colder than that the ambient temperature while the optimal temperature is 5-10^oC. The cooling of the Solar Dripper's body is based on fundamental physical process – evaporation –  employing the solar heat as the driving force. Evaporation of water is one of the most effective methods for cooling since upon evaporation of 1kg of water about 2,260kj are consumed, which means that evaporation of one liter of water can reduce the temperature of more than 50 liters of water by 10^oC. In order to achieve evaporation without the need to refill water, desiccating materials are used and the solar radiation provides the energy necessary to recover the desiccants. The Solar Drippers are therefore composed of the dripper's body containing water solution and a solar collector containing desiccants. The desiccants in the solar collector adsorb the liquid's vapors and thus allow low steam pressure in the dripper's body and thereby the evaporation process is accelerated and the temperature of the remained liquid reduced. When the desiccants are saturated the process stops until the desiccants are heated by the solar radiation, causing in turn adsorbtion of water to be returned to the dripper's body.

The Solar Drippers could be designed in various configurations, including a chain of small drippers, or a lengthy pipe with an elongated solar collector on top of it. The daily capacity of the small Solar Dripper is about 0.1l while every meter length of pipe-style Solar Dripper supplies about 1l/day.

Solar Dripper could also provide an excellent source for alternative water supply. Sophisticated design of the pipe-style Solar Dripper, with or without humidity adsorbing material, could be placed underground or inside construction units, such as in concrete, in a way that the water dripping will take place inside the pipe and the water will flow into a container.

 It is also possible to locate a set of pipes, one on the top of the other, to increase water capacity in given spaces.