The monograph deals with the issue of the landfill gas generation and its use in a combined heat and power system (CHP). This book focuses on the verification of the influence of a number of wells on the operation of the cogeneration unit. The utilization of landfill gas has several important advantages. In particular, the energy use of the byproduct of landfill and the recovery of waste. In addition, the combustion of landfill gas eliminates the negative environmental impacts resulting from free discharge of formed gas up to the air. The monograph highlights the simulating of the landfill gas generation and provides a comparison of the simulation results with the measurements carried out in the landfill Úholičky. The monograph describes a proposal of the utilization of the recultivated area in the Úholičky landfill, the economic evaluation of the proposal, which includes the budget of the particular items of the Photovoltaic Power Plant (FVE) of the landfill site, and the estimated revenues and payback period of the investment for the proposed output. The data contained in the monograph indicated that landfilling is the most common method of waste treatment in Slovakia.