John Charalambidis worked from 1990 to 2002 at the Center for Renewable Energy Sources in the Rational Use of Energy department and in the Energy Policy department.

From 2002 until today, he is working at the Regulatory Authority for Energy, Waste & Water with the main objective of evaluating applications for RES projects. From 2002 to 2013 in the Decision Processing and Documentation unit as coordinator of the licensing process and evaluation of applications for Renewable Energy Projects. From 2013 to 2017 coordinator of the Working Group for monitoring the Licensing of RES projects, from 2018 to 2021 Head of the Licensing Process & Record Keeping Department and from 2021 Head of Renewable Energy Sources and Storage Directorate with the main objective of the licensing of RES projects and Storage, as well as their monitoring.