sistac Portfolio
Christoph Göller & Julia Römer
Located in: Germany, Pilot: Kenya | Scalability: Global
“Helping health workers preserve lifesaving medicines by providing electricity independent refrigerators”

Based on the IEA World Energy Outlook in 2015, around 1.2 billion people on this planet live without electricity. One to this fact related problem is the lack of appropriate cooling systems or refrigerators. The consequence is that food expires faster and 75% of vaccines in developing regions are damaged due to faulty cooling. Julia Römer had the vision to solve this problem and developed together with her team the “Coolar System”, which runs completely without electricity and doesn´t need any hazardous refrigerants or lubricants. Instead, it works completely with hot water from solar heat and follows the repeating cycle of evaporation, adsorption, drying, and condensation.


The Coolar system can provide the most economical, durable and sustainable solution to preserve lifesaving medicine such as vaccines, improve the opportunities of transportation and facilitate food storage in regions with unreliable or expensive electricity. Several successful field studies are carried out for example in Kenya, India or on Tenerife. The feedback and results of this studies help to develop new and better prototypes and to create a product that have a great impact in remote regions with warm climates.