Jacek Kostrzewa has more than 30 years of sustainable energy experience with a focus on Central and Eastern Europe. Over the course of his career, he has managed more than a dozen international technical assistance programs, with particular emphasis on building the residential energy efficiency sector across the region. His leadership has spanned large-scale program design and implementation, donor-funded technical assistance, and capacity-building for governments and financial institutions.

Jacek holds an M.Sc. in Environmental Engineering from the Technical University of Warsaw, Poland, and an M.B.A. from the Romanian–American Business School of the University of Washington and the Academy of Economic Studies in Bucharest, Romania. He is fluent in English, Polish, and German, and also speaks French, Romanian, and Russian.