About the Challenge


Run by the Kigali Cooling Efficiency Program (K-CEP) in collaboration with the Global Cool Cities Alliance, Sustainable Energy for All and Nesta’s Challenge Prize Centre, the Challenge aims to demonstrate clean, effective and affordable cooling solutions, spurring the market for cost-effective passive cooling. This will improve sustainable access to cooling where there is the greatest need, and reduce the climate impact of cooling over time.


What you can win


$1 million will be awarded to the team that has developed the best sustainable and transferable model for rapid deployment of cool roofs in developing countries. The team should have deployed 1 million square meters of new, effective and durable solar reflective coating and/or materials on roofs of regularly occupied buildings in an eligible developing country between August 2019 and 1 December 2020.

Applicants are invited to apply to the challenge by 20th May 2019, when the 10 best proposals will be chosen and each awarded a $100,000 ‘Boost Award’ to support them in reaching the final goal.

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Who can enter the Challenge


Entrants to the Challenge must deploy cool roof solutions in an Article 5 Group 1 developing country as defined in the Montreal Protocol. 

Teams can enter as a single organisation or as partnerships of several organisations, but there must be a single lead applicant that is a registered legal entity. Example lead applicant organisations include local or national government organisation, university or research institution, international or local non-profit organisation, for-profit company or international organisation. Partner organisations may be of any type but there must be at least one in-country partner organisation if the lead applicant is based internationally.


How you can apply


Online registration is now open to register your interest in applying to the Challenge. The application window for the $100,000 Boost Awards will open in January 2019 and close on 20 May 2019. See the timeline below for more details.




Online registration opens.



28 January 2019

Applications open for $100,000
Boost Awards.

20 May 2019

Deadline for applications for
Boost Awards.

August 2019

Up to ten applicants selected and
awarded $100,000 each.


2020/ 2021

1 December 2020

Deadline for applicants to achieve scale.

March 2021

Winner announced and awarded
US$1 million.


Why we are running this Challenge


The recent paper by SEforAll and K-CEP, Chilling Prospects: Providing Sustainable Cooling For All, directly linked strategies to deploy more highly reflective “cool” roofs and walls with achieving the goals of the Paris Climate Accord, Sustainable Development Goals, and the Montreal Protocol. 

By minimizing the amount of heat generated by solar energy absorbed by buildings, reflective building surfaces reduce the demand for cooling energy for those that can afford it while also providing a sustainable passive cooling solution for the billions of people who do not have the economic means to access mechanical cooling options, in rural poor, urban slums or homeless shelters. 

Reflective roof surfaces not only have an impact on individual buildings, but deploying them across a whole community can have a net effect on reducing local ambient temperatures. Further, the deployment of reflective materials creates sustainable job and skills opportunities for low skilled workers in both rural and urban contexts.

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Get involved


If you’re interested in applying to the Million Cool Roofs Challenge, or subscribing to general updates about the Challenge, complete the ‘Register Your Interest’ form via the button below and we’ll be in touch with further details.