Three-Year Exploitation Tests of a Photovoltaic Plant in a Zero-Energy Single-Family House under the Polish Conditions

摘要

The subject of the study is the analysis of the energy self-sufficiency of a single-family house, equipped with an on-grid photovoltaic plant and electric heating system. The study is based on 3-year tests of a real plant located in southwestern Poland. The main aim of the research was to determine the conditions for full balancing of the energy produced and returned from the grid in relation to the legal system in Poland. The climate conditions and trends of their changes at the location of the house, as well as the impact of the angle of inclination and orientation of the modules on energy yield were analyzed. The annual and monthly balances of energy produced, fed into the electricity grid and consumed during the period of 2017–2019, were presented. The monthly and annual variability of generated energy was subject to statistical evaluation. The payback time and the value of the avoided CO2 emissions were calculated. The final effect of the research was to determine the energy, economic and ecological profits of the analyzed installation. It was shown that in the "net-metering" system in force in Poland, it is possible to fully cover the energy demand just by using solar energy, and the reimbursement for a photovoltaic plant will take place after approx. 8 or 12 years, depending on the electricity tariff chosen.