Energy obtained from renewable sources is an important element of the sustainable development strategy of the European Union and its member states. The aim of this research is, therefore, to assess the potential and use of renewable energy sources and their effectiveness from the regional perspective in Poland. The research covered the years 2012 and 2018. The diversification of production and potential of renewable energy sources was defined on the basis of biogas and biomass. Calculations made using the data envelopment analysis (DEA) method showed that, in 2012, only three voivodeships achieved the highest efficiency in terms of the use of biogas and biomass resources; in 2018, this number increased to four. Comparing the effective units in 2012 and 2018, it can be seen that their efficiency frontier moved upwards by 56% in terms of biogas and 21% in terms of to biomass. Despite a large relative increase in the production of heat from biogas by 99% compared to the production of heat from biomass by 38%, the efficiency frontier for biogas did not change considerably. It was found that the resources of solid biomass are used far more intensively than the resources of biogas. However, in the case of biogas, a significant increase in the utilization of the production potential was observed: from 3.3% in 2012 to 6.4% in 2018, whereas in the same years, the utilization of solid biomass production potential remained at the same level (15.3% in 2012, 15.4% in 2018). It was also observed that, at the level of voivodeships, the utilization of biogas and biomass production potential is negatively correlated with the size of this potential. The combined potential of solid biomass and biogas can cover the demand of each of the studied regions in Poland in terms of thermal energy. The coverage ranges from 104% to 1402%. The results show that when comparing biomass and biogas, the production of both electricity and heat was dominated by solid biomass. Its high share occurred especially in voivodeships characterized by a high share of forest area and a low potential for biogas production (Lubuskie Voivodeship, Zachodniopomorskie Voivodeship).

In many countries, energy security is treated as a priority for the coming decades, and at the same time energy production from the vast majority conventional energy sources does not meet environmental protection criteria. Hence, the need to use renewable energy sources (RES), which can largely satisfy energy needs. The aim of the study was to identify possibilities of creating autonomous energy regions (ARE) in Poland, based on renewable energy sources. Attention was paid to the role and significance of the potential of rural areas in this respect, taking into account the possibilities of increasing energy production from these sources in individual regions of Poland. The research was conducted on a regional level (division into voivodships) and on a local level (division into powiats, which form voivodships). When assessing the potential for constructing ARE based on RES, the following energy sources were taken into account: water, wind, sun, biogas and biomass. It was found that the highest RES potential versus energy consumption can be obtained in powiats where the share of arable land and forests exceeds 80%. The research showed that in most regions of Poland (powiats, voivodships), there is a large potential for obtaining additional energy from RES, which would cover over 73% of the country’s demand for electricity. This could be the basis for building energy independence on a local scale. The results of the study indicated that as many as seven regions would become self-sufficient in terms of electricity demand.

Increasing biogas production in the Three Seas Initiative countries (3SI) is a good way to reduce greenhouse gas emissions and to increase energy self-sufficiency by replacing some of the fossil energy sources. An assessment of the biogas production potential carried out for the 3SI at the NUTS 1 and NUTS 2 level shows that the potential of this energy carrier was stable for the period (from 2010–2021). The results showed that it can cover from approximately 10% (Hungary, Slovakia) to more than 34% (Estonia, Slovenia) of natural gas consumption; moreover, there is strong variation in the value of potential at the regional level (NUTS 2) in most of the countries studied. The biogas production forecast was carried out with the ARIMA model using four regressors, which are GDP, biogas potential utilisation, natural gas consumption and investments in RES (renewable energy sources) infrastructure, including changes in the EU energy policy after 24 February 2022. In the most promising scenario (four regressors), the results obtained for the period from 2022–2030 predict a rapid increase in biogas production in the 3SI countries, from 32.4 ± 11.3% for the Czech Republic to 138.7 ± 27.5% for Estonia (relative to 2021). However, in the case of six countries (Bulgaria, Lithuania, Hungary, Austria, Poland and Romania) the utilisation of 50% of the potential will most likely occur in the fifth decade of the 21st century. The above results differ significantly for those obtained for three regressors, where the highest rise is predicted for Bulgaria at 33.5 ± 16.1% and the lowest for Slovenia, at only 2.8 ± 14.4% (relative to 2021).

Biogas production within cooperatives and energy clusters that include both food businesses and biogas plants seems to be a good way to both improve financial health and increase energy self-sufficiency. The paper assesses the financial health of more than 2100 food businesses operating during the period of 2014–2020; the analysis was based on data from public statistics. The financial analysis carried out using the ROS (Return on Sale) indicator and the SI for the study (saving indicator) showed that the average SI/ROS increased by more than 2.78-fold over the study period. Moreover, for 185 powiats, the observed growth remained above average over a period of one to five years. The application of the Data Envelopment Analysis (DEA) method allowed the relative efficiency of biogas utilization to be calculated at the powiat level (former LAU level 1). It was found that the utilization of biogas potential within cooperatives and energy clusters grouping food businesses is most effective mainly for urban powiats.

Biogas production in Poland and Ukraine seems to be a good way to both reduce greenhouse gas emissions and increase energy self-sufficiency by supplementing conventional energy sources. The aim of the research was to assess the potential of biogas production and the possibility of increasing it at the regional level of both studied countries and was conducted in 2018. The study included an analysis of seasonal heat demand, and the results showed biogas heat surpluses and shortages in each region. The financial side of the investment discussed using the example of the selected administrative unit showed that the construction costs of the biogas plant would be paid back after 7~9 years. The presented results also showed that Polish regions have much higher variation of biogas production potential (0.14~1.09 billion m³) than Ukrainian regions (0.09~0.3 billion m³). The analysis of the possibilities of increasing the potential based on the cultivation of maize in wastelands showed that in this respect, the Ukrainian regions have better opportunities compared to Polish regions. In the case of 20 regions, the maximum use of the potential of biogas should result in an increase in the share of renewable sources in the energy mix to above the level of 25%. Poland and Ukraine have comparable biogas production potentials of ~10 billion m³ annually, which results in a comparable number of biogas plants needed to consume that potential as well as the number of new jobs. The above analyses were also carried out at the LAU level (powiats and raions) where the potential of regional cooperation for four border regions is discussed.