WATER OUT OF THE AIR ON A LARGER SCALE
Extract water from the air with solar energy.
Water scarcity is deeply related to the global climate change. Arid zones and deserts are expanding on all continents. But there is one practically endless source of water, which is accessible even in the most arid climate zones: the atmosphere.
Typically, the air in a desert contains 4 grams of vapor per cubic meter. This amounts to 4 million liters of fresh water in a cubic kilometer. So there is a tremendous potential and challenge here!
In our Rainmaker Project we extract clean water from the atmosphere with different technologies. They all use natural phenomena such as the solar radiation, the night time radiative cooling, the transport of air by solar chimneys and more.
IN GETTING WATER
The human made climate change is rapidly influencing the global weather patterns. One of the most critical elements of this change are droughts, the sinking of the water levels and the desertification of entire regions. Billions of people, mainly in the Global South, are threatened by this dangerous development. As fresh water for human consumption and agriculture is the most important prerequisite of life, gaining water out of the air is of utmost importance.
The technical challenge is, that the water vapor in the atmosphere is extremely diluted (some few grams up to 20grams per cubic meter of air). In order to get this liquid fresh water out of the air, you need a minimum energy input, which is equivalent to the evaporation energy used by the sun (0,57KWh per Liter).
In order to avoid a further acceleration of the climate change, this energy must be produced with renewable energies.
OF THE SUN WATER COLLECTOR
Hella Boccara Initiative is supporting several Rainmaker technologies. Four of them are gaining water out of the air by cooling a volume of air below the dew point, and thus condensing the vapor into liquid, fresh water.
Namen der verschiedenen Systeme mit Link (Sun Water)
The Sunwater Project as well as the bigger Cold Box Configuration Projects are using the so called Cold Box as core element of the cooling process. The Cold Box is operating round the clock thanks to two different operating modes, one for the night and one for the day.
During night, cooling is done by radiation into the clear night sky, and during the day, photovoltaic panels drive an eco-cooling compressor.
The produced cooling energy is stored in a closed water tank.
COLD BOX – NIGHT TIME OPERATION
A STEP BY STEP DISCRIPTION
At night, the lids of the Cold Box open automatically.
The black radiator emits infra-red radiation into the sky.
The water in the storage tank under the radiator cools down.
The cold of the water is transmitted into an air condensation chamber via a heat exchanger.
COLD BOX – DAY TIME OPERATION
In the morning, the lids of the Cold Box close automatically. The photovoltaic modules mounted on the lids produce electricity, which feeds an eco-cooling compressor. This compressor cools the water in the storage tank even more.
A solar chimney sucks the air across the heat exchanger which is cooled by the stored cold water. The vapor in the air condenses on the cold heat exchanger's surfaces and is collected in a vessel.
Ideally, the chimney acting as a double window is serving at the same time as a wall of a greenhouse, under which plants find ideal growing conditions.
Functioning demonstration units of the Rainmaker are being built at the TTT-Center in Portugal.