This “Inverted Umbrella” Harvests Drinking Water and Solar Energy
Indian couple Samit Choksi and Priya Vakil Choksi invented the “Ulta Chaata”
As the use of solar power increases and the price falls, it becomes increasingly clear that sunshine is a powerful, popular and practical renewable energy source. Potable water is a universal right and basic need, to which millions of people lack access. A wife and husband duo in India are harvesting both solar energy and drinking water with one unique device called “Ulta Chaata,” which means “inverted umbrella,” in Hindi. As you can see below, this is an apt name for the attractive canopies that open to the sky like blossoms.

Ulta Chaata is the first project released by Think Phi, a startup focusing on green technology formed by Samit Choksi and his wife Priya Vakil Choksi in 2015. Ulta Chaata harvests rainwater during monsoons, solar energy during dry seasons and provides shade as well. Priya, who has a Masters in sustainable design as well as a degree in architecture and Samit, who specializes in software in the development industry, came up with the idea for Ulta Chaata after studying and working around the world in locations including Singapore, London and Atlanta.
“After moving back [to India], we saw that the pollution and the increasing climate change are major reasons for concern in India. The one thing that struck us was that we get heavy rains here and yet all this water is getting wasted,”
Samit told Better India. He also explained that they wanted to collect this rainwater before it hit the ground, when it was the purest.
Ulta Chaata has two levels of filters. The first uses carbon filtration, in which active carbon removes impurities. The filter lowers the water’s turbidity or relative clarity to within a World Health Organization potable water limit.
Ulta Chaatas are generally installed in clusters, ideally of 10 or more. Typically, 15 Ulta Chaatas connect to one intelligent “Phi box,” which contains a second fine filtration layer that removes bacteria. After passing through both levels of filtration, drinkable water is produced. One Ulta Chaata can collect and prepare as much as 100,000 liters of potable water during each rainy season.

Solar panels installed on the canopies collect solar energy into the device’s batteries. The energy is used to power the Ulta Chaata as well as their individual lights. The battery can also be used as backup energy for nearby structures. Forbes India reported that Ulta Chaatas have “a maximum solar capacity of 1.5KW,” and that the “lighting system which provides various levels of programmable lighting options and a mobile charge unit, thereby making it a completely self-sustaining installation for the outdoors.”
The Ulta Chaatas’ ability to provide shade is valuable as well. Members of Think Phi’s team, which has now grown to include 12 people, were invited to speak to representatives of the Indian Railways to explore the benefits of Ulta Chaata use. Samit said their unique, upside-down-umbrella-shaped devices can provide “environmentally friendly shading at a lower cost,” when compared to the current railway platform roofs.
An Ulta Chaata comes with a 10-year warranty and costs between Rs. 4.5 and 5 lakh (one lakh equals about $1500, so they cost about $7,000 in total). Because users can quickly make back their initial investment in energy savings, Think Phi brands this device as “the world’s first integrated system for clean water, energy, shade and delivering returns in less than one year.”
Priya explained to Better India that human-driven climate change was a big inspiration for them in developing well-designed and efficient sustainable energy systems;
“The world has always gone through periods of global warming and cooling which is an effect of natural causes. However, in this century we have gone through the biggest shift in the last 400,000 years and this time it is driven solely by man-made causes, us.”
As well as containing the secondary water filtration level, the Ulta Chaatas’ Phi box serves several other purposes. It detects filter clogs and sends messages back to Think Phi if the unit needs cleaning or servicing. It also measures and displays the water and energy being harvested to passersby. Other sensors monitor water purity and the functioning of the lights. Ulta Chaatas users are empowered with an app to directly communicate questions or issues to the company. Ulta Chaatas are currently used in over 50 locations throughout India.
Think Phi’s mission is, “to be earth’s most sustainable company. We hope to get there by building products that accelerate the advent of utilizing and managing sustainable resources.” Follow their innovative work toward this goal on Twitter.