Approaching problems with global warming due to the use of fossil fuels, means that new system solutions have to be investigated. This report investigates the possibility to expand an existing photovoltaic system with a wind turbine generator to simplify the expansion of renewable energy sources. Through an extensive literature study and simulation in SIMULINK the result has been developed and tested. It shows that it is possible to connect a wind turbine generator to the same inverter as the PV-modules if no MPPT algorithm for the PV-modules is integrated. To protect the inverter a dump load has to be connected. Because of the complexity a DC-coupled system brings, AC-coupling is advised when expanding PV-modules with a WTG. The optimal wind turbine is considered to be a permanent magnet synchronous generator connected to the AC-bus through a full-effect inverter. The turbine should be chosen according to the intended location based on wind conditions and desired energy production.