###### Contents  
* 1 Introduction
* 2 In recent years, fluctuations in the European and global economy, caused by several factors that were not previously predictable, have been observed. These included the COVID-19 pandemic with subsequent economic fluctuations during consecutive epidemic waves and preventive measures in the form of lockdowns, and Russia's invasion of Ukraine, which had a dramatic impact on the European economy. These events primarily resulted in the breaking of supply chains and the introduction of an embargo on many products (including fossil fuels), which translated into a rapid increase in their prices and, in extreme cases, the lack of their availability.  
Poland, despite one of the largest hard-coal deposits (total proved reserves at end of 2020) in Europe (22.53 billion Mg) [1], has become its importer since 2017 (Figure 1). This was caused by increasingly difficult exploitation conditions (deep underground mines with many natural hazards), gradual withdrawal from hard coal in the energy industry and the availability of cheap raw material, mainly from Russia. The diagram of the couplings that occurred in the above-mentioned range is presented in Figure 2.  
The import of hard coal from Russia to Poland decreased from 12.9 million Mg in 2018 to 9.1 million Mg in 2020. According to the data of the Industrial Development Agency (ARP), 8% of the volume of coal imported from Russia in 2020 was used for the production of electricity, mainly in combined heat and power plants, which need coal of better quality that is difficult to produce from Polish deposits. When translating these shares into the upcoming years, it can be assumed that there will be a gap of about 1 million Mg of hard coal, which will have to be replaced in the upcoming years in the production of electricity. One of the solutions is to replace this volume with the rapidly developing renewable energy sources (RES) in Poland, especially PV sources.  
Figure 1: Export and import of hard coal in Poland.  
Figure 2: The impact of low prices and availability of coal on the increase in its import to Poland.  
According to data from Energy Market Agency (ARE) [2], at the end of June 2022 (Figure 3) the total installed capacity in PV amounted to 10.36 GWp (an increase year by year over 93%) and in wind energy 7.48 GWp (an increase every year by 11.7%). In the period of January 2019-June 2022, photovoltaics recorded the largest increase in installed capacity among all electricity generation technologies in Poland (by over 1600%).  
Significant increases in installed capacity were also observed in the case of natural gas thermal power plants (+44%) and wind farms (+28%). Conventional coal-fired power plants increased their capacity by 6%, while the installed capacity in those that use lignite, decreased by 4% (closure of power units at the Patnow power plant).  
In 2020, domestic electricity consumption was lower than in 2019, due to the COVID-19 pandemic and the preventive measures imposed by lockdown [3]. In the following year, an increase in demand for electricity along with an increase in its production in the country was observed--and 819 GWh was imported at the end of 2021 (Table 1). A comparative analysis of the first 6 months of 2022 with the previous year shows a slight increase (1.21%) in electricity consumption with a significant increase in production (7.25%), which translated into a positive balance of intersystem (international) exchange at the level of 1 708 GWh. The large increase in the volume of energy production from renewable sources (mainly PV and wind) by almost 55% is also worth noting. Maintaining the upward trend from the first 6 months, domestic energy consumption should not exceed 177 TWh with a positive international exchange balance.  
The aim of the research is to assess the impact of RES development in Poland on changing the energy generation profile and reducing CO\({}_{2}\) emissions by determining which conventional energy sources will be replaced.  
Figure 3: Installed electric power in Poland by fuel.