The solar drip, also known as KondensKompressor, is a system that traps evaporated water from the soil in a built-in reservoir using solar energy. 

The moisture condenses on the inside walls and falls in the form of solar drip directed through the walls and back to the ground. 

At night, it has a double function as it can also collect a small amount of dew.

The system can help save water for irrigation, which is vital for  growing plants.

It is estimated that solar irrigation can reduce irrigation water needs up to 10 times compared to other traditional irrigation systems.

The water produced by the KondensKompressor is free of salt, nitrates and other contaminants, so it can even be used to desalinate seawater.

Knowing the great problems that many countries face in obtaining fresh water, even though very effective water desalination systems already exist, this technique could help farmers with fewer resources to increase the efficiency of their crops.

How to build a Kondenskompressor

Despite its high efficiency, you can build your own Kondenskompressor using everyday materials.

It can be used for domestic or professional use. It requires little maintenance, just replenish the water tank when necessary and pull weeds from the inside.

Given the controversy generated about the possible contamination of the water by plastic bottles, you can also use glass bottles although cutting them is a little more complicated.

Step by step

You will need PET bottles (specifically two per plant). One of the bottles needs to be at least twice the size of the other.

Cut the bigger bottle at the base. In the interior, place the smaller bottle cut in half.

This smaller bottle must be placed on the ground and filled with water. You can even use salt water from the sea.

The larger bottle must cover it. You must be able to pour water into the smaller bottler when opening the larger one.

Place the bottles next to the plant you need to water,

You can place dry leaves or straw around the system to maintain the humidity of the soil and make the solar distillation system even more efficient.

Because the materials are so readily available, this technique can be easily used in poor countries with long dry seasons and even in desert areas with access to a source of fresh or saltwater.

Why does it work?

Once the system has been set up correctly, all that remains is to wait for the forces of nature to act. 

When the sun's rays hit the large outer bottle, the temperature of the air inside it rises (greenhouse effect), causing the water on the ground and in the inner bottle to evaporate, with the consequent saturation of humidity in the air inside the small ecosystem.

At this point, the water condenses in the form of droplets on the walls of the bottle, which then slide down and fall to the ground, moistening it.

The maintenance of the solar drip irrigation system only requires the replenishment of water in the small bottle when necessary, as well as cleaning of weeds that may have sprouted inside the main bottle.