The paper investigates the competitiveness of the Polish hard coal mining sector as a fuel source for heat and power generation. The main objective of the study is to make a quantitative assessment of the impact of the price relationship between domestic and imported steam coal on the consumption of domestic fine coal in the Polish heat and power generation sector. For this purpose, a long-term mathematical model of the Polish steam coal market is employed and scenarios that mimic the relationship between domestic and imported steam coal prices is developed. The following results are analysed: the volume of total domestic steam coal consumption under the scenarios analysed, the absolute difference in domestic steam coal consumption under the scenarios analysed in comparison with the scenario 0%, the total imported and domestic steam coal consumption in the period analysed. In addition, the results were depicted in cartograms in order to present the distribution of domestic and imported coal consumption in the various regions of Poland. The results of the study indicate that the supply of steam coal in Poland can be completely covered by domestic mines when the price of domestic coal is from –40% to –20% lower than that of imported coal. For the remaining scenarios, the consumption of imported coal increases and reaches its highest value in the scenario +40%, in which imported coal covered of 71% of total steam coal consumption in Poland over the period. The conclusions presented in this paper provide valuable findings and policy insights into the competitiveness of domestic mines and management of domestic production both in Poland and other countries in which power generation systems are mostly dominated by coal.