Indian start-up makes ‘Water from Air’: Sustainable climate solution or mere fancy?
On Earth Day 2023, we bring to you a sustainable development story about a Bengaluru-based start-up that generates water by tapping moisture in the air.
Half of the world's population could be living in areas with water stress as early as 2025, according to a United Nations report. India, where groundwater is critical for food security and drinking, is already grappling with water table decline. This alarming trend highlights the urgent need for sustainable water solutions in India and around the world. (ALSO READ: There’ll be tomorrow if there’s water, says Modi as he launches Jal Jan Abhiyan)
One such solution is extracting water from the air around us. Water from air? It may sound like science fiction, but innovators present this rather unconventional method of water extraction as potential answer to helping tackle the world's water scarcity problem. (ALSO READ: Google doodle for ‘Earth Day 2023’ depicts action plan for greener future)
How does an air-water extraction system work?
A water-air extraction system uses a dehumidifier to remove moisture from the air. It can be done in a variety of ways, the most common being by cooling warm, humid air. By this process, air loses its ability to hold moisture, causing water vapour to condense into droplets. Something similar can be seen while we operate our air conditioner.
A Bengaluru-based start-up Uravu Labs has made a device to capture water from the air. They, however, have taken a different approach. They have used an air-water extraction system based on desiccation where a saltwater solution called brine is used to remove moisture from the air. Air passes over the brine, and as it absorbs moisture, the brine becomes saturated. The brine is then heated with solar energy to evaporate the water, and the resulting water vapour is collected.
You can relate water absorption to home salt becoming wet and sticky in rainy season.
What is the benefit of a desiccation-based system over a cooling system?
Swapnil Shrivastav, co-founder of Uravu Labs, told Hindustan Times that their aim is to have an environmentally friendly, sustainable solution. "Our air-to-water system uses less energy (300 watt-hours per litre) and its requirement is independent of humidity change."
While Uravu Labs is currently using solar energy, Shrivastav claims his device can be powered by the waste heat of industries and biomass.
Capacity and business model
Uravu Labs delivers packaged water to the hospitality industry, premium cafes, beverages industry from an in-house facility based in Bengaluru. Their present capacity is 1000 litres per day (LPD), with an average cost of ₹4–5 per litre of water production. They have an ambitious goal of scaling up to 1 lakh LPD within two years and expect a lowering of costs.
Challenges to Air water extraction system
As the device extracts water present in the air, it requires a weather condition with sufficient humidity. It may not work in dry and cold climates, while more humidity also poses a challenge.
To tackle this, Shrivastav says they can modify the quantity of brine to accommodate changes in relative humidity without increasing operational costs.
However, the device requires a temperature of more than 12–15 Celsius and a relative humidity of more than 25–30 percent, Swapnil adds.
But while water is chemically dihydrogen monoxide (H20), our bodies require water that contains soluble minerals and salts. Additionally, the air pollution may find its way into the dehumidified water.
On this, Swapnil says their current target customers are those who require pure water, like the beverage industry, while they can also mineralize the water based on customer requirements. He also claims that their device can filter air pollutants.
The cost, size of the device, maintenance requirement, and environmental concern of proper desiccation disposal are other challenges that can hinder wide-spread use of this type of air-water extraction system.
A ray of hope in dark times!
The Central Ground Water Board (CGWB) monitors groundwater levels in the country and found that in 2021, over 33% of monitored wells showed a decline of 0–2 metres, and some areas in major cities like Delhi, Chennai, and Lucknow had experienced a decline of over 4 metres when compared to the 2010–2019 average. (ALSO READ: India suffering from worst water crisis in its history: NITI Aayog)
The solution proposed by the Indian start-up can specifically help the beverage industry, which often has to face backlash from locals over concerns about water table depletion due to excessive extraction of water. (For context: Coca-Cola plant's permit cancelled in TN after farmers protest)
We need more such initiatives and technological advancements in our fight against the climate crisis.