March 2002: Energo NV first positions itself as a biomass specialist in the renewable energy sector and a developer of combined heat and power (CHP) projects.

February 2006: Theolia becomes majority shareholder in Energo. Energo is renamed Theolia Benelux.

November 2006: Theolia Benelux takes 51% stake in Polargen,
a Benelux-based developer and operator of CHP plants in the industrial greenhouse sector.

June 2007: Having taken the decision to separate its non-wind assets, Theolia lists its CHP assets on Alternext Paris, renaming the company Thenergo.

September 2007: Thenergo acquires Leysen, a Belgian waste management group.

November 2007: Thenergo acquires the remaining minority share (49%) of Polargen via a share swap.

December 2007: Thenergo acquires a majority stake in ENRO, re-branded tse AG (Thenergo sustainable energies AG), a German biomass CHP developer and operator and co-owner of the companies distributing heat to industrial and residential clients.

April 2008: Agri-entrepreneurs Boerenbond, through its Agri Investment Fund (AIF), makes an investment of €10 million in Thenergo, marking the beginning of an important industrial and strategic partnership.

August 2008: Thenergo transferred its listing from Alternext Paris to Euronext Brussels and Paris.

October 2008: the fomer Leysen shareholders invested € 2 million in Thenergo and hold 21.7 % of the Thenergo shares.

April 2009: ParticipatieMaatschappij invests € 10 million in Thenergo with a mandatory convertible obligation.