After the Chernobyl disaster, he and his wife, Ursula Sladek, initiated a movement in their hometown Schönau im Schwarzwald to become independent of nuclear energy, achieving that goal in 1997.

[6] After ten years of campaigning and raising awareness, they founded the first German green power utility, the Elektrizitätswerke Schönau (EWS), in 1994.

[1][5][7][8] With a system that combined efficiency and power-saving strategies, it became possible to satisfy the power consumption of the community.

[3] He was awarded the 1996 WWF Umweltpreis "Öko-Manager des Jahres" from the German magazine Capital.

[4] In January 2004, the Sladeks were awarded the highest order in Germany, the Federal Cross of Merit, for their involvement with the environment.