Dr. Arnulf Jäger–Waldau is a Scientific Officer and Senior Scientist at the Energy Efficiency and Renewables Unit, Directorate C: Energy, Transport and Climate. He works for the European Commission's Joint Research Centre, since 2001. The assessment of renewable energy technologies, the effectiveness of their implementation, their integration into energy infrastructures and the role of renewable energy for climate change mitigation is part of his work portfolio.

Since 1987 he works in the field of material research for solar cells and holds patents on semiconductor material deposition for thin film solar cells and solar module design.

He has more than 250 publications in peer reviewed journals and conference proceedings ranging from materials research for PV and solar cell development to market studies and policy evaluations for Renewable Energies. He is the author of the European Commission's annual "Photovoltaic Status Report", which is published annually since 2002.

From 2011 to 2014 he was the Technical Chairman of the European Photovoltaic Solar Energy Conference (EUPVSEC) and served as European Co-Chair of the 6th World Conference on Photovoltaic Power Conversion in Kyoto, November 2014 as well as Conference Chairperson of the E-MRS Spring Meeting in 2009 and 2013.

Dr. Jäger-Waldau was a Lead Author for Solar Energy of the Special Report of the IPCC on Renewable Energy and Climate Change Mitigation. He served as a reviewer of the 2012 Global Energy Assessment Report (GEA) p the 5th IPCC Assessment Report (AR5) and the special IPCC report on Global Warming of 1.5 ºC published in 2018.

Since 2013 he is a reviewer of the annual Medium-Term Renewable Energy Market Report of the International Energy Agency.

He serves as Academic Committee Vice Chairman of the Asian Photovoltaic Industry Association (APVIA), member of the International Advisory Board of the Warsaw University Photovoltaic Centre and member of the Scientific Advisory Board of the Solar Research Centre of the Bulgarian Academy of Science. From 2005 to 2013 he was a member of the Executive Committee of the European Materials Research society (E-MRS).