Energy systems are changing worldwide: new energy policies promote more sustainable energy productions, including Variable Renewable Energy sources (VREs) such as wind or solar. The long-term implications of the variability and relative unpredictability of these non dispatchable energy sources need to be assessed, for example with energy scenarios. Indeed, electricity is not a homogeneous good: its value depends on the time, space and how variable a production is. Long-term energy models are used, VREs integration challenges being a hot topic in energy modelling. An assessment of long-term energy models is necessary to understand how they represent the specific constraints of VREs on the rest of the power system. Therefore a new typology is proposed for comparing both long-term energy models and power sector models. This comparison shows that – despite all the recent modelling efforts – no long-term energy model represents in detail all the impacts of VREs on the power sector. For example, the sequential representation of the electricity storage operation is too precise for many long-term models. Therefore we develop a dedicated new power sector module, EUCAD (European Unit Commitment And Dispatch). The particularity of the work is that it is connected to POLES (Prospective Outlook on Long-term Energy Systems), one of the most technology-detailed long-term energy models. We present the first results of this new detailed electricity module.