Tambunan is the director of National Laboratory for Energy Conversion Technology at BPPT. He received his master degree from TU Delft and PhD from RMIT Australia in mechanical engineering. He has more than 10 years’ experience in design and development of integrated and modern sugar factory, waste-based power plant construction, geothermal power plant turbine development, electricity motor development, charging station development, and assessment on reliability, availability, maintenance and safety of light rail industry in Indonesia. Tambunan is also part of Ikatan Keluarga Besar Nederland (IKANED) presidium. IKANED is a platform for alumnus from The Netherlands residing in Indonesia.