Stefan Kessler primarily focuses on climate protection, energy technology, energy concepts and energy policy programmes, impact analyses, implementation issues, development cooperation and technology transfer. He has extensive international experience.

In 1987, he graduated as a Mechanical Engineer with the main focus Energy Systems from the ETH Zurich (CH). Subsequently, he managed pioneer projects for Alpha Real AG in the areas wind energy and photovoltaic systems. From 1992 to 1994, he completed postgraduate studies in Development and Cooperation (NADEL) at the ETH Zurich. During that period, he suspended his studies for 16 months to do fieldwork for HELVETAS and Swisscontact in the areas photovoltaic pumps and systems in Lesotho and Indonesia.