By Raul Mannise
An important fraction of the fresh water that humanity consumes is used in crop irrigation, much of it being wasted in ineffective irrigation systems. Although there are efficient irrigation systems, such as conventional drip systems, they tend to be expensive and are therefore available to few farmers, especially in less economically favored countries.
The solar drip system comes to change this panorama since it offers a very efficient, simple and economical irrigation system to install that can help millions of farmers in the world to achieve an increase in their production using much less water.
About solar drip
Solar dripping, also known by the name Kondenskompressor, is an irrigation technique designed to achieve optimum use of water by using the Sun's energy as the driving force behind the distillation process and movement of water. It is a surprisingly simple and efficient system by means of which it is possible to reduce the amount of irrigation water by up to 10 times compared to traditional irrigation systems.
The Kondenskompresor system also has the advantage of making it possible to use brackish water or even sea water for irrigation, since it transforms salt water into fresh water.
In the manufacture of the kondenskompressor, a very abundant and easy-to-obtain material such as PET plastic bottles can be used. Its manufacture and installation is very simple and is within the reach of any farmer, whether in a domestic or professional environment. It also requires very little maintenance, being only necessary to replenish the tank with water when necessary and remove the plants that may have grown inside the Kondenskompressor.
With the application of this technique, the plants develop fully using only the necessary amount of water and preventing that which is not used from evaporating.
By requiring materials that are very abundant waste and being extremely simple to manufacture and install, this technique can be very easily used in poor countries with prolonged dry seasons and even in desert areas with access to some source of fresh or salt water ( for example those near the sea).
On how to make a Kondenskompressor
To make a kondenskompressor, it is only necessary to have two PET plastic bottles (the plastic water bottles) with a lid, one larger than the other (for example, a 5 liter and a liter and a half). It is also possible to use two glass bottles that meet these same characteristics as long as we have a method to cut them.
The large bottle must be cut to remove the base while the small one must be cut approximately in half, only the lower part being useful.
The base of the small bottle is placed on the ground filled with water and the large bottle is placed on it. The relative position between the two must allow us that when opening the lid of the large bottle we can pour water over the small one.
Both bottles thus arranged (The kondenskompressor) have to be placed next to the plant that we want to water. Hay, straw or dry leaves are placed around the plant and the Kondenskompressor.
On how solar drip works
Ways in which conventional irrigation water is wasted on a crop
To properly understand the operation of the solar drip system it is necessary to know the ways in which water is used, evaporated and lost in a growing area with conventional irrigation.
When we water an area of land in a conventional way, a small part of this water is taken by the plant directly from the ground through the roots. The plant uses this water in its development and ends up being perspired through the leaves. That is why for a plant to survive it needs a regular supply of water.
Another good part of the water that falls on the ground evaporates directly into the atmosphere without passing through the plant or being useful to it.
It must also be considered that another part of the water, if irrigation or rain is abundant, seeps through the subsoil into deeper layers of earth, entering the underground flows and may not be useful for cultivation.
The greater or lesser degree of transpiration from the plant and evaporation from the soil depends on the degree of dryness of the air and its temperature.
About the operation of the Kondenskompressor
The solar drip technique works in a very similar way to how solar stills do, using the energy of the Sun to evaporate the water in an area and through the form of the ingenuity direct it where it interests.
When the Sun's rays fall on the Kondenskompressor, the greenhouse effect occurs inside, raising the air temperature and causing the water in the tank to evaporate. The air inside the hood becomes saturated with humidity, which produces condensation in the form of drops on the wall. As long as the kondenskompressor continues to be exposed to the Sun, the evaporation continues and larger and larger drops are formed that end up sliding down the walls and falling on the ground, watering it. In this way, the natural water cycle is reproduced on a small scale.
When the Sun hits the Kondenskompressor, the water inside the container evaporates, which condenses on the walls of the large bottle.
If the Kondenskompressor remains in the Sun, evaporation continues and the drops get bigger and bigger and begin to precipitate down the walls reaching the ground and moistening it.
The advantage of drip irrigation systems, both solar and conventional, is that the water is supplied strictly enough and necessary for the development of the plant, avoiding the waste of water in areas where it will not be useful to the plant and where it will finally evaporate or filter, losing itself.
As there is no direct connection with the outside atmosphere, the water is not lost through the hood. Hay or straw is available to prevent evaporation in the areas around the plant and the Kondenskompressor, which maintains moisture in the soil. In this way the only way in which the water evaporates is through the leaves of the plant once it has already been used in its development.
Bottles can be buried underground, ideal for windy locations.