Electricity production in Poland is stable and ranges from 160–170 TWH a year. The share of renewable energy sources (RES) is increasing. Poland increased its share from 6.9% in 2010 to 12.7% in 2019 and 16.1% in 2020. The share of hard and brown coal decreased in Poland from 87.8% in 2010 to 73.5% in 2019. Wind energy (9.2%) and natural gas (9.2%) are the most important sources of RES in electricity production. The purpose of this research is to discover the changes in renewable energy production, and the impact on electricity production in Poland. Our research showed the extent of development of RES in Poland and other countries of the European Union. The share of renewable energy sources in electricity production increased as the effect of energy policy of the European Union. We also evaluated the impact of the COVID-19 crisis on the renewable energy market and electricity production in Poland, and other countries of the European Union. Because of the shortage of data, we presented changes at the beginning of the COVID-19 crisis in 2019–2020. First, we described the sustainable development and energy policy of the European Union. Then, we described and used methods, including regression analysis, as the most important method. We also found that the power capacity in Poland increased, with the increases coming from solar radiation (11,984%), wind energy (437.8%) and biomass installations (324.7%) in 2010–2020. The biggest electricity producers in the EU are France and Germany. These countries also use nuclear energy, which helps to meet the increasing demand. To check the impact of power installed from renewable energy carriers we conducted a regression analysis. This method provided a correlation between electricity production from renewable energy sources and investments in renewable energy carriers. We wanted to discover the impact of RES installations, and their impact on electricity production in Poland. The statistical analysis was based on data from 2010–2020. Our research points out that the most important factors shaping electricity production were installations using energy from solar radiation and hydropower installations.