This paper presents an overview of photovoltaic systems and new technologies that are currently less commercial. Primarily silicion-carbide and graphene which have excellent properties, but they are more difficult to exploit. In the first two chapters, we discussed the operation of solar cells, extraction of the most significant parameters that are describing them and preview of the currently available silicon based solar cells is given. Also, new technologies are described which are currently being investigated to maximize the efficiency of solar cells. Graphene has found its potential applications even here. The third chapter describes energy containers, their current status and projections using graphene. The fourth chapter gave a brief overview of the properties of silicon carbide and graphene and their applications in photovoltaic and other systems. The fifth chapter describes the simulation for each of the three cases; silicon, silicon-carbide and graphene. Simulations have been made in Simplorer 7.0 Student Version, which is limited to 50 working elements. For each material, a certain voltage drop is chosen for IGBT according to their properties, and according to their properties we got efficiency of the inverter. For this converter we can see that graphene is potencially the most efficient. Sixth chapter describes wave forms of MOSFET current and voltage and control signal. As we compare those two cases it gives us conclusion that switching losses of silicon-carbide technology is much more less than silicon technology.