EP 2,3-12 is a part of EUROPOWER, an innovative low-carbon transition model for the European electricity and heat systems up to 2050. The EP 2,3-12 model enables an exploration of the transition pathways by varying certain key parameters, such as energy demand, fuel mix, and electric/heat load. Additionally, the model provides an overview of the expected system-wide costs and carbon emissions associated with static and dynamic features and decisions. The EP 2,3-12 model is capable of analyzing the impacts of policy measures, such as renewable share targets and emission allowances, as well as energy demand flexibility options. EP 2,3-12 provides insight into the directional changes required for a successful low-carbon energy transition in Europe.