**5. Conclusions**

In the years 2019–2020, the Polish government offered prosumers a program of cofinancing PV installations called "My Electricity". The amount of the subsidy was up to max. 50% of eligible costs, up to a maximum amount of PLN 5000 (EUR 1111). In the assumed period, more than half of the photovoltaic micro-installations established in Poland received funding under the "My Electricity" program. The total cost of the subsidy program was EUR 251 million. Currently, the program continues as part of the third round from July 2021 with changed conditions, including a reduced maximum grant amount of EUR 667 for installations.

The average power of PV micro-installations with co-financing is 5.72 kWp. Most installations were built in the very industrialised Silesian Province (27,160), the lowest in the Podlaskie Province (4824). In total, installations with a total capacity of 1295 MWp were created under the "My Electricity" program. With the productivity of PV installations at the level of 1025–1104 kWh/kWp/year (differentiated by region), these installations will contribute to the production of approx. 38 TWh of green energy over 30 years.

It is broadly recognised that PV systems can be treated as a source of green energy. The environmental effects of the "My Electricity" program implementation in Poland, measured by the avoided CO2eq emissions based on the IPCC GWP 100a indicator, are highly positive in light of the fact that the Polish power industry is still largely based on fossil fuels. The detailed LCA analysis of the installations allowed for the determination of CO2eq emissions at the average level of 9390.7 kg per system, while the average CO2eq emission per functional unit was 0.056 kg CO2eq/kWh, which corresponds to the Central European conditions of insolation. The particular indicators are influenced by the type of technology and location of the system, as stated in this study. Future analysis should consider the relationship between the size of the system and the CO2eq emissions to show the areas with the greatest effectiveness of support.

According to the analysis, while reducing the carbon footprint of energy units by 92–95%, PV systems built in the "My Electricity" program can contribute to the avoidance of 26–42·106 Mg of greenhouse gas emission in 30 years of life cycle perspective. This, together with the analysed economic aspects, leads to the conclusion that the use of this type of financial instrument is fully justified, in particular in the case of stimulating the development of energy markets with a large share of conventional energy sources.

**Author Contributions:** Conceptualisation, P.O., D.M. and A.Z.; methodology, P.O. and A. ˙ Z.; software, ˙ P.O. and A.Z.; validation, D.M. and M.O.; formal analysis, D.M. and M.O.; investigation, P.O., D.M. ˙ and M.O.; resources, A.Z. and P.O.; data curation, P.O., A. ˙ Z., D.M. and M.O.; writing—original draft ˙ preparation, P.O., A.Z., D.M. and M.O.; writing—review and editing, M.O.; visualisation, P.O. and ˙ A.Z.; supervision, P.O.; project administration, P.O. and M.O. and funding acquisition, P.O., A. ˙ Z., ˙ D.M. and M.O. All authors have read and agreed to the published version of the manuscript.

**Funding:** The publication was co-financed by the subsidies from: the Faculty of Environmental Engineering, Lublin University of Technology, statutory founds FD-20/IS-6/042; the Faculty of Energy and Fuels, AGH University of Science and Technology, No. 16.16.210.476; the Faculty of Environmental and Power Engineering, Cracow University of Technology.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
