Apart from basic knowledge and practical application of electrical engineering and energy technology, Prof. Heier offers lectures in the field of renewable energies such as Nutzung der Windenergie (Use of Wind Energy), Regelung und Netzintegration von Windkraftanlagen (Control and Grid Integration of Wind Energy Converters), Regelung Elektrischer Energieversorgungseinheiten (Control of Electrical Energy Supply Units) and seminars like Windkrafttechnik (Wind Power Technology) as well as Netzintegration dezentraler Einspeisesysteme (Grid Integration of Decentralized Supply Systems).
Furthermore, Prof. Heier keeps close contact to many universities, research institutes, utilities and manufacturers in various developed and developing countries. He also supervises scientists with their PhD and students with their work and practical training in different foreign institutes. He was the representative of the University of Kassel in the European Academy of Wind Energy and cooperation representative for the University of Fes (Morocco). In cooperation with the University of Ilmenau and the University of Graz he introduced a Master Study in Renewable Energies at the Damascus University and furthermore, he has developed technical training centres at the Universities of Homs and Lattakia for using solar energy in Syria within two EU-Tempus projects.
Prof. Heier participated as a member in national and international bodies as well as in internal and external board and committee meetings. As an German expert he represented German interests a lot of times at the Internationalen Energieagentur (IEA) and the European Commission. As appointed member he took part in the German Engineer Association expert commitee renewable Energy (VDI-Fachausschuss Regenerative Energien) up to March 2012 and was elected vice-president to the International expert commitee of Germanischer Lloyd "Zertifizierung und wiederkehrende Pruefung von Windkraftanlagen (Certification and periodical Inspection of Wind Energy Convertrers) up to the end of 2010. He was chairman of many meetings of VDI-conferences and, from September 2003 to December 2009 also chairman of the Scientific Committee of the Bundesverband Windenergie (German Wind Energy Association).