Abstract. Next years will be very important for the development of the Polish energy system. Substantial part of the existing capacities are obsolete and need to be replaced or at least deeply modernised to fulfil expected emissions regulations. A hybrid of TIMES-PL and TIMES-MACRO energy-economic models was used to analyse the possible changes in the power generation mix and economic impact of different scenarios that combine the climate and air pollution regulations. The results show that to maintain the CO 2 emission reduction trend a combination of measures is needed including the use of renewables, nuclear, natural gas and clean coal technologies. However, such transition in the energy sector will lead to a cumulative GDP loss in the near future once the possible GDP gains could happen after 2045 in which the economic, technical and legislative conditions are very difficult to foresee.