Utilization of renewable energy sources tends to increase due to growing global power demand, reducing cost of renewable technologies, diminishing fossil fuel supplies and increasing awareness of environmental protection. These technologies make it possible to answer the ever-growing power demand in a clean, environmentally friendly way, but also make it possible to introduce electricity to remote, developing regions. One of the main challenges of renewable energy systems is power optimization as the amount of these sources can vary strongly even in a single day. Therefore, the scale of the energy system and the size of its components must be selected to fit the consumption demand even in non-ideal environmental conditions and a controlling system has to be built which can balance the power-fluctuation.
This thesis introduces the topic of hybrid renewable energy systems, summarizes the operation and relevant characteristics of photovoltaic systems, wind turbines, battery technology and microgrids. The goal of the project was to build a model of a wind and solar powered energy system in MATLAB Simulink, which can simulate the behaviour of a system in island mode, in case of various environmental conditions and to employ a power optimization strategy which can control the power generation to match the demand according to these conditions. Simulations of islanded operation mode have significant practical application, as remote off-grid microgrids (e.g. islands, military bases) have no connection to the utility grid because of their location, security or economic issues, thus they always operate islanded. The implemented simulation model is capable of harnessing solar power through Maximum Power Point Tracking and regulating the wind power generation through a blade pitch control mechanism. An introduced battery pack model supplies for the consumption when the power generation is insufficient and can consume the excess power when the generation is more than the demand, thus it stabilizes the power balance. The simulation was tested with real, measured power consumption, wind speed and solar irradiance characteristics.