Zdanowski led Edelman's energy practice for almost three years, where his responsibilities included providing counsel to energy sector businesses, his LinkedIn profile states.
A spokeswoman for Edelman told PRWeek that Zdanowski's former client portfolio would be managed by members of the agency's 80-strong corporate reputation team.
He starts today (22 May) at Madano, handling PR for clients focused on renewables, nuclear power and "innovative" energy technologies, a statement from the agency said.
Zdanowski said: "As new energy technologies shape and disrupt the market, the communications required to support these changes will be as important as the initiatives themselves."
He will lead a team of seven and will report to the agency's managing partner Michael Evans.
Before joining Edelman in 2014, Zdanowski was director at PR firm BGR Gabara, where he advised international clients including governments and multinational corporations.
Prior to this he was a director at Hill+Knowlton Strategies, advising energy clients in Russia and Kazakhstan.