Extracting Potable Water From The Air!

As the world sees drinking water sources become scarce amid unprecedented climate changes, Bengaluru-based startup Uravu Labs is creating water out of thin air through renewable energy sources.

Star Wars legend Luke Skywalker’s hot desert planet, Tatooine, had a moisture farm that used “vaporators” to pull drinking water from the air. For a long time, vaporators had remained a figment of science fiction until two NIT Calicut graduates faced water rationing in college after the waterbody which supplied water to their campus dried up.

Propelled by a looming water crisis, Swapnil Shrivastav and Venkatesh R decided to turn fiction into reality in 2016. They didn’t realise that six years later, they would have managed to achieve it with Uravu Labs. Uravu means a spring of water in Malayalam.

In 2017-18, the duo was joined by Govinda Balaji and Pardeep Garg. Together, the futuristic four designed a device to capture water from the air using a hygroscopic substance called a desiccant with a saltwater solution called brine. The air is passed over the brine, which absorbs the moisture, which, in turn, saturates the solution. The brine is then heated with solar energy to evaporate the water, and the resulting water vapour is collected.

The machine is equipped with various sensors to monitor five main parameters. “We monitor the relative humidity of the ambient air inside the device before condensation and the temperature of the air and of the water being formed. Flow rates are also measured at different points, including air and water flow rates. To keep track of the overall performance, we also have a sensor to measure the amount of water produced by the system. Lastly, we ensure water quality by monitoring pH and total dissolved solids (TDS) levels in the water output,” elaborates Shrivastav.

Initially, the data from these sensors was gathered using a Raspberry Pi and visualised through an AWS-based dashboard for analysis. As the startup progressed towards an industrial-grade setup in 2021-22, they transitioned to using programmable logic controllers (PLCs) for control and data acquisition.

“The innovation in our electronics side is centred around real-time problem solving. We need to know the exact conditions, such as humidity levels, water production, etc., in real time. This demands a lot of decision-making and analysis on the board level, and the robust electronics hardware gives us more control and real-time responsiveness in our water capture devices,” explains Shrivastav.

Uravu water factory
Uravu water factory

The company’s initial prototype utilised silica gel and had mirrors to focus solar energy and heat on the silica gel to produce water. The self-contained unit could produce about 5 litres of water a day. Each unit required dedicated components like fans, valves, and pumps, which affected the cost while scaling.

To optimise the size and scale of production, the startup switched to a liquid desiccant—calcium chloride solution. The desiccant is sprinkled through a mesh in the absorber units to increase the surface area as a fan draws air. After it absorbs moisture from the air, the desiccant is pumped to a separate desorber unit where the solution is heated to 65 to 70 degrees celsius by a coiled pipe filled with hot water. The hot and humid air is passed to a low-power, air-cooled condenser. Each absorber unit can collect as much as 200 litres per day. While the output of traditional condensing systems can vary considerably depending on the local humidity, Uravu’s device can achieve the same output in drier areas by simply loading more desiccant into the absorber.

The co-founders (L-R): Govinda Balaji (Engineering), Swapnil Shrivastav (Business), Pardeep Garg (Technology & Business), Venkatesh R (Design & Operations)
The co-founders (L-R): Govinda Balaji (Engineering), Swapnil Shrivastav (Business), Pardeep Garg (Technology & Business), Venkatesh R (Design & Operations)

The company has coupled six absorbers with two desorber units to create Uravu’s 1,000-litre-per-day machine. The latest upgrade to Uravu’s design can be coupled with different heat sources, including solar thermal panels, biomass burners, and industrial waste heat.

Based in Bengaluru, the startup’s lone design and assembly unit has a total in-house capacity of 3,000 litres per day, out of which currently, 1,800 litres are being utilised daily for customers in the hospitality industry.

It is eyeing the production of other beverage products at the plant, such as tonic water, ginger ale, and flavoured water, by setting up an assembly line for the water produced across different pH ranges.

It has partnered with several manufacturers and vendors based in Bengaluru and Coimbatore to supply customised components to build the product. The startup is looking to expand its operations from 2025 to other metro cities in the country and is ambitiously targeting a foreign location in Europe or the Middle East.