Ashok Gadgil
Physicist Ashok Gadgil developed inventions including UV Waterworks and the Berkeley-Darfur stove, enabling access to clean drinking water and greater energy efficiency for people across four continents.
Born in Mumbai (then Bombay), India, in 1950, Gadgil developed an interest in science and engineering at a young age. His parents supported his interests and allowed him to have his own lab, where he could explore and experiment. He even tested different chemical reactions and sourced materials like zinc and carbon rods from dry cell batteries. Gadgil also joined a local hobby club where he had access to a carpentry shop and found mentors in science. “Those experiences surely contributed to developing the sense of what might work,” Gadgil said in an interview with the National Inventors Hall of Fame®. “They surely contributed to developing the sense, on the physical side, of manipulating objects and understanding hydrodynamics.”
Choosing to study physics, Gadgil earned his bachelor’s degree from the University of Mumbai (previously known as the University of Bombay) in 1971 and his master’s degree from the Indian Institute of Technology Kanpur in 1973. He then came to the U.S. and earned both a master’s degree in 1975 and doctorate in 1979 from the University of California, Berkeley.
Following his studies, Gadgil accepted a position as a staff scientist at the Lawrence Berkeley National Laboratory (Berkeley Lab) in the Energy and Environment Technology Division. Here, he researched problems of solar energy applications and worked on computer programs to simulate solar heat transfer systems.
In 1983, Gadgil returning to his native India, and earned four Indian patents for solar heaters in a few years. However, he found that bureaucracy made it increasingly difficult for him to develop and apply his ideas to make a positive societal impact. So, in 1988 Gadgil returned to Berkeley Lab and continued research in the field of energy efficiency and started research projects in indoor air quality.
In 1993, a deadly strain of Bengal cholera began spreading throughout India, killing thousands each month at the peak of the epidemic. Gadgil realized he could help. “I started saying to myself, ‘I’m at this amazing national lab and there’s so much knowledge at our fingertips, and I should be able to simply do something that reliably and affordably disinfects drinking water,’” he recalled.
Using a multidisciplinary approach and advice from experts across Berkeley’s campus, Gadgil created UV Waterworks, an effective, inexpensive technology that uses ultraviolet (UV) light to kill disease-causing bacteria and viruses in the water. Although UV light had previously been used to disinfect water, Gadgil’s design improved on previous devices by suspending the UV lamp above a channel of flowing water to prevent buildup of algae and other bacteria on the lamp. Using just 60 watts of electricity, UV Waterworks could provide clean drinking water for 2,000 people at a cost of only $70 annually. Gadgil’s technology has since been used by WaterHealth International Inc. to provide clean drinking water to tens of millions of people throughout India and Africa. Discussing the success of UV Waterworks, Gadgil said, “It’s really wonderful to go and meet people who use this – who use this water and who appreciate what they’re able to afford.”
In the early 2000s, Gadgil focused his efforts on another crisis: the dangerous living conditions of displaced women in Darfur, a region of western Sudan. Women make up most of the refugee camp population, and when they must leave the camps to find firewood, they face the threat of assault. To help address this reality, Gadgil collaborated with researchers and engineers in Berkeley Lab, students on the UC Berkeley campus, and with Oxfam America and other nonprofits to invent the Berkeley-Darfur stove – a portable stove that uses 55% less fuelwood than traditional Darfur cooking methods. This invention reduces fuel demands for those living in refugee camps, while also reducing their exposure to the risk of assault. To raise funds for the manufacture, transport and distribution of Berkeley-Darfur stoves, Gadgil co-founded the nonprofit Potential Energy, which had distributed more than 60,000 stoves as of 2023.
Gadgil also has innovated utility-financed efficient lighting programs that have been implemented in 38 countries in Eastern Europe, Asia, Africa and Latin America, and he pioneered affordable methods for removing arsenic from drinking water. During 2015-16, Gadgil led his team and fellow collaborators in designing, building, commissioning and training local workers in India to operate a plant that takes in water containing a highly toxic level (250 ppb) of arsenic and delivers safe drinking water. This revolutionary arsenic removal system is exceptionally cost-effective, serving clean drinking water to 5,000 people for just 1 U.S. cent per liter.
Gadgil continues to research ways to improve the water and energy supply of people in need. In addition to his lab work, he was the Andrew and Virginia Rudd Family Foundation Distinguished Chair Professor of Safe Water and Sanitation at UC Berkeley, and concurrently Senior Faculty Scientist at Berkeley Lab, until 2023, when he retired. He has continued his research at UC Berkeley as a professor on research recall, and a distinguished professor emeritus. He has received many honors and awards, including the National Medal of Technology and Innovation, Zayed Prize for Sustainability, Heinz Award and Lemelson-MIT Award for Global Innovation.
Reflecting on what has motivated him throughout his career, Gadgil said, “The common theme is: How can we apply our understanding and creativity in engineering science to make the world a better place in terms of reducing human suffering and maybe alleviation of poverty?”