Siersdorfer joined Siemens in 1987 and assumed his current role at Siemens Energy in 2020 following the company’s spinoff from Siemens. He leads a team of around 3,000 people. In 2022, Siemens Energy launched the Alliance for Industry Decarbonization with the International Renewable Energy Agency, bringing together more than 50 international companies to decarbonize heavily-emitting sectors.