The OSeMOSYS project offers open-access energy modeling to a wide audience. Its relative simplicity makes it appealing for academic research and governmental organizations to study the impacts of policy decisions on an energy system in the context of possibly severe greenhouse gases emissions limitations. OSeMOSYS is a tool that enhances the potential for the training of highly qualified professionals. Basic training is possible via the UTOPIA model. This paper proposes an extended version of this model to help non-expert individuals fully grasp its powerful yet easy-to-use capabilities. The step-by-step presentation shall be of great use for professors to embed this material in class and for energy professionals new to the field of energy modeling to learn how to use a techno-economic approach.