Nowadays with commercialization of cogeneration business, expansion of electricity production and profit maximization are the main optimization criteria for power plants. That is why, the number of combined heat and power (CHP) plants in Europe change their current operation modes to different ones – operation in cycling mode with shut down or load reduction of generating units at night time. This research provides the investigation of changes in Riga CHP-2 plant operation modes, as the result of opening of Latvian price area in Nord Pool Spot (NPS) power exchange. Combined cycle gas turbine (CCGT) units of Riga CHP-2 plant were chosen as investigation objects. Negative and positive aspects of cycling operation of Riga CHP-2 plant were explored under conditions of open electricity market. Finally, some measures for modernisation and upgrade of Riga CHP-2 were recommended to improve efficiency of cycling operation and flexibility.