Harvest Water from Air
The depletion of freshwater sources and rising water scarcity across the world, companies are now looking to tap the atmosphere that holds around six times as much water as all the world’s rivers.
Estimates of atmospheric water (when liquified) in India is 1,360 BCM which is closed to utilizable water resource of 1,123 BCM (Groundwater - 433 BCM and Surface water -690 BCM). India's current population estimated requirement of 2 BCM safe drinking water annually.
|The solar-powered atmospheric water generator|
(Image Source: Sciencemag)
An atmospheric water generator (AWG)s are machines that extract water from humid ambient air. Water vapour in the air is condensed by cooling the air below its dew point, exposing the air to desiccants, or pressurizing the air.
The contaminants in atmosphere water could be high but it can be removed with the integrated water filtration system.
To date, an industrial AWG of 1,000 litres/day capacity could cost upwards of Rs. 1.0 Lakh, a domestic unit with a 40 litres/day capacity costs between Rs 30k-40K
This apart, the average cost of electricity consumed for 40 L/day Machine works out to be close to Rs 56 a day or Rs 1,680 a month.
Pros and cons of AWG technology:
- AWG is a very effective technology to harvest water from the atmosphere since all it needs are air and electricity, which can both be obtained from natural energy sources.
- Even though AWG requires humidity to produce freshwater, it can be placed anywhere.
- It is valuable to areas that don't support life due to lack of water.
- AWGs are known to be more expensive than other water harvesting technologies.
- The efficiency of the system depends on the humidity of the air. They are a less attractive option in places with the dry climate.
- The contaminants in atmosphere water could be high, particularly for a country like India, which has a dense population. The water filter needs to be properly maintained.
AWG machines have a negligible effect on the environment even if entire India consumes from the source simultaneously. The success of the AWGs will, therefore, depend upon the pricing and efficacy of the product.