Dr Hans-Joachim Ziesing served on several advisory boards, e.g. Enquete Commission of the Parliament of Berlin "Energy Policy in Berlin" (1983 to 1985), ad-hoc committee with the Federal Ministry of Research and Technology "Solar based hydrogen economy" (1986 to 1988), Enquete Commission of the Parliament of Schleswig-Holstein (1989 to 1992), Enquete Commission "Sustainable Energy in the Context of Liberalisation and Globalisation" of the 14th German Bundestag  (2000 to 2002), "National Advisory Committee (NAC)" to the International Conference for Renewable Energies 2004 (2003 to 2004), 1989 to 2006 chairman (1989 to 1999) and member of the Berlin "Energy Advisory Board" (Energiebeirat), and since 2007, member of the Berlin "Climate Protection Advisory Board" (Klimaschutzrat). since 2005 Delegate of the Consultative Commission on Industrial Change (CCMI), a body within the European Economic and Social Committee (EESC).

In his scientific career, Dr Hans-Joachim Ziesing has conducted a large number of studies with a wide spectrum of topics. His specific interests include analyses, forecasts and scenarios concerning the energy field, economics of specific energy systems with emphasis on renewable energies and combined heat and power systems, interdependency between economy, energy and environment, analyses of the environmental impacts of different energy strategies, recommendations in the field of energy and environmental policies, climate protection policies, and emissions trading. Finally, Dr Hans-Joachim Ziesing was highly engaged with basic studies on the German National Allocation Plan for the period 2005-2007 and 2008-2012 within the framework of the Emissions Trading Scheme of the European Union. For many years he accompanies the energy and environmental policy with his academic advice. He publishes widely on these subjects and is invited regularly as an expert to participate in and speak at relevant conferences and workshops. In 2005, he was decorated with the Federal Cross of Merit of the Federal Republic of Germany.