Systems for the production of electricity require the previous collection of gas from the organic matter of municipal waste. Collection of landfill gas is done by a degassing system. In the case of the Niš landfill, this system was partially built by installing biothorns for the evacuation of landfill gas into the air. The paper presents the results of testing landfill gases, which include: determination of the volume fraction of methane (CH 4 ), carbon dioxide (CO 2 ), hydrogen sulfide (H 2 S), carbon monoxide (CO) and hydrogen (H 2 ). Measurements were made at the control points at the exit from the biothorn, at the closed and rehabilitated fields S 2 and S 3 , simulated results at the control point of the pilot project of the active system, at the exit from the horizontal and vertical drain, at the active field S4, Niš landfill. Measurements were performed using the electrochemical method, with a GEM TM 2000 Plus gas analyzer, once a month. The LandGEM emission model was used to estimate the energy potential of methane. The paper concluded that the most energy-efficient method for waste disposal is the use of an active degassing system. Using an active landfill gas extraction system, a 1MW power plant can be built.