In the News: Awardees Announced in Engineers Without Borders-USA’s “Chill Challenge”

Competition Seeks to Provide Affordable Refrigeration for Off-Grid Communities

Denver, CO—Engineers Without Borders USA (EWB-USA) today announced grant awards for seven proposals in its “Chill Challenge,” an initiative to develop affordable refrigeration technologies for off-grid households in the developing world.

The development of off-grid refrigeration has enormous potential for improving the lives of millions of the poorest and most vulnerable people on the planet. Refrigeration means less food waste, more opportunities for farmers and improved nutrition for households.

Furthermore, as highlighted by the COVID-19 pandemic, refrigeration is critical for delivering vaccines and other health care services to remote off-grid communities.

The following teams will be awarded grants ranging from $30,000 to $50,000 to develop their innovative concepts:

  • Purdue University, Ray W. Herrick Laboratories, West Lafayette, Indiana
    Cold Storage Battery for Domestic Refrigeration: This project will evaluate the use of heat from clay or brick cook stoves to drive an intermittent sorption “cold storage battery,” which requires no electricity to operate.
  • New Leaf Dynamic Technologies, New Delhi, India
    Ice Maker Powered by Farm Waste: The Company will use its “GreenChillTM” adsorption technology to build a 1000 kg/day ice-maker powered by biomass  in  the form of husk, straw, wood, or biogas. Solar PV will provide electricity to power  auxiliary equipment.
  • Arup, London, UK
    Arup’s Passive Cooling Box: Arup’s Advanced Digital Engineering team will test a passive refrigeration system that uses, as a cold source, passive cooling materials that emit heat as infrared radiation through the “atmospheric transmission window” into space. Phase change materials will provide cold storage.
  • Xergy, Inc., Harrington, Delaware
    Off-the-Grid Refrigerator Utilizing Solid-State Refrigerants: Xergy will build an adsorption refrigerator using hydrogen and metal hydride as the working pair. Hot water provided by solar thermal collectors will drive the process.
  • Solar Cooling Engineering, Hohenheim, Germany
    Solar Ice Maker Using Key Components and Engineering: This team will use solar powered SelfChill® cooling units for its ice-maker to produce 100-120 kg  ice per day. The concept is fully scalable and will allow a local assembly and the  integration of  locally available materials. The ice-maker can be powered without electrical batteries.
  • Purdue University, Ray W. Herrick Laboratories, West Lafayette, Indiana Combined Heating and Cooling for Agricultural Applications: This project will examine the potential for a simultaneous heating and cooling vapor  compression system in which evaporator capacity is used to create ice and condenser heat to dry crops. The system will be powered entirely from solar.
  • Imperial College London, Clean Energy Processes (CEP) Laboratory, South Kensington, UK
    Affordable Decentralized Off-Grid Icemaking: The CEP team in collaboration with Solar Polar will design and demonstrate a solar-driven diffusion absorption  refrigeration (DAR) icemaker based on new working-fluid pairs and innovative designs aimed at increasing system performance, affordability and lifetime.

More information on the winning teams and their proposals is here.

The Chill Challenge was launched in September 2019, to solicit innovative proposals for more affordable refrigeration for off-grid communities. In response, EWB-USA received 43 proposals from 36 teams from universities, companies or NGO’s, and individuals. Sixteen were U.S.-based, and 20 were located overseas, including teams from Cameroon, Ethiopia, France, Germany, Nigeria, South Korea, Switzerland, Uganda and the UK.

Fourteen of the best proposals were shortlisted, and final grant winners were selected by a distinguished panel of reviewers, including EWB-USA volunteers and international refrigeration experts. According to Andrew Dowdy, an EWB-USA volunteer working on the challenge since inception, the reviewers were “impressed by the range of innovative ideas proposed by participants. It was difficult to select only a handful of proposals for grants.”

EWB-USA anticipates that the outcomes and lessons learned from this competition will inspire greater participation and innovation that will ultimately provide communities with expanded access to affordable refrigeration technology that is compatible with off-grid energy sources.

EWB-USA is proud to have ASHRAE as a Chill Challenge partner, contributing to our expert panel of technical reviewers and providing outreach for the Challenge.

Open Philanthropy generously contributed $500,000 to EWB-USA to establish the Challenge.

More information on the Challenge can be found at challenge .



Engineers Without Borders USA
Engineers Without Borders USA (EWB-USA) is a nonprofit organization that builds a better world through engineering projects that empower communities to meet their basic human needs and equip leaders to solve the world’s most pressing challenges. EWB-USA’s thousands of highly skilled volunteers work on more than 650 projects in partnership with local communities, NGOs, governments and UN agencies in 45 countries to design and implement sustainable and technologically appropriate infrastructure solutions. For more information visit and connect on Engineers Without Borders USA on Facebook, LinkedIn and Twitter.

Open Philanthropy identifies outstanding giving opportunities, makes grants, follows the results, and publishes its findings. Its mission is to give as effectively as it can and share the findings openly so that anyone can build on them:

Founded in 1894, ASHRAE is a global professional society committed to serve humanity by advancing the arts and sciences of heating ventilation, air conditioning, refrigeration and their allied fields. As an industry leader in research, standards writing, publishing, certification and continuing education, ASHRAE and its members are dedicated to promoting a healthy and sustainable built environment for all, through strategic partnerships with organizations in the HVAC&R community and across related industries. For more information and to stay up-to-date on ASHRAE, visit and connect on LinkedIn, Facebook, Twitter and YouTube.

About the Author
Engineers Without Borders USA builds a better world through engineering projects that empower communities to meet their basic human needs and equip leaders to solve the world’s most pressing challenges.