The tutorial will focus on a recent, “hot” area of circuits and systems: up-to-date power electronics converters and inverters to be used as interface between green energy cells and local or national grid. After establishing the requirements imposed by this application to the electronic circuit, basic capacitor- switched cells, inductor-switched cells, capacitor-inductor-switched cells and capacitor-coupled inductor-switched cells will be formulated. They will serve as the start point in a graph-oriented, systematic general approach to develop and design suitable high-performant electronic circuits answering the application constraints. The available solutions will be classified and reviewed in a comparative way. The challenges and the trade-offs in designing such circuits will be discussed. On-going misunderstandings about switched-capacitor converters and their ill-fated influence on understanding the design of the converters in conjunction with the renewable energy will be elucidated. The tutorial will not stop to presenting the best state-of the art solutions in terms of large dc gain, minimum component cost, minimum EMI pollution and high efficiency in processing the electrical energy, but will give the participants insights and tools for developing power electronic circuits for new challenges that the scientists and designers can expect from future environmental-friendly energy sources used to supply smart grids.