Andrees Gentzsch was born on 12 November 1964 in The Hague/The Netherlands. After secondary school and civilian service in Wiesbaden, he studied law at the Westfälische Wilhelms Universität in Münster and at the Université du Droit et de la Santé in Lille/France. Following the state examination in law in 1990, he completed his legal traineeship at the Appeal Court of Bremen before passing the second state examination in law in 1994.
Andrees Gentzsch then began his professional career as a lawyer in the legal department of BEB Erdgas und Erdöl GmbH, Hannover, rising to Head of the Legal Affairs division. In 2004, he moved to the German Electricity Industry Association (VDEW) in Berlin and headed the Legal Affairs and Environment divisions as well as Central Services and Human Resources.
In 2007, in the newly formed BDEW, German Association of Energy and Water Industries, Andrees Gentzsch was appointed head of the Legal Affairs division as well as the Human Resources and Finance divisions. In April 2009 he was appointed a member of the Management Board. On 1 December 2016 he was appointed a member of the General Executive Management Board of BDEW and since then has been responsible for the Energy Networks, Regulations and Legal Affairs division.
Andrees Gentzsch is married and the father of two children.