The physicist and systems analyst began his professional career in elementary particle physics and numerical physics.
Initial studies on climate change then led to a switch to applied environmental research.
As early as the 1990s, he wrote scenarios for 100 percent supply with renewable energies.
For more than 40 years he worked in various institutions in the field of energy, resources and the environment – at national and international level in various functions – dealing with politics, administration, associations, science and companies.
In addition, he has co-founded or been involved in various companies (e.g. Naturstrom) and organizations (e.g EUROSOLAR, WCRE).