This paper presents the energy and economic analysis of hybrid cogeneration power plant located in Poland, that consist of a hard coal co-generation unit, water boilers, and gas engines. The sensitivity analysis is performed to study the effect of a significant change occurred in the energy market since the beginning of 2018. Emissions purchase costs increased in EU Countries of about similar to 200% and fossil fuels costs of similar to 15%, which is reflected in electric and thermal energy price. To understand the level of the impact, detailed analysis with optional scenarios of further price increase is performed. The detailed analysis is performed by using a dedicated mathematical model of the installation, with respect to the real operation parameters, technology obstructions and macroeconomic situation. The study examined five different scenarios, which consider the price increase of CO2 emission allowances and fuels. The input heating power profile was chosen for turnover seasons, to reflect production units operate out of nominal parameters at lower efficiencies. The performed analysis reveals the weakness of hard coal technologies on the changing energy market, especially on the CO2 allowances price increase.