This dissertation focuses on selected aspects of network congestion arising in liberalized electricity markets and their management methods with a special weight placed on the integration of increased renewable generation in Europe and Germany. In a first step, the theoretical concepts of congestion management are introduced complemented by a review of current management regimes in selected countries. In the second step, the European approach of managing congestion on international as well as national transmission links is analyzed and the benefits of an integrated congestion management regime are quantified. It is concluded that benefits can be achieved by a closer cooperation of national transmission system operators (TSOs). Thirdly, the German congestion management regime is investigated and the impact of higher renewable generation up to 2020 on congestion management cost is determined. It is shown that a homogeneous and jointly development of generation and transmission infrastructure is a prerequisite for the application of congestion alleviation methods and once they diverge congestion management cost tend to increase substantially. Lastly, the impact of intermittent and uncertain wind generation on electricity markets is analyzed. A stochastic electricity market model is described, which replicates the daily subsequent clearing of reserve, dayahead, and intraday market typical for European countries, and numerical results are presented.