Prediction of the energy self-sufficiency rate of major new renewable energy types based on zero-energy building certification cases in South Korea

Abstract

There is an increasing interest in new renewable energy sources for achieving net zero emis-sions. Consequently, the construction industry has mandated zero-energy building certification (ZEB), through the usage of new renewable energy. However, because of the variations in the energy self-sufficiency rate (ESR) among the new renewable energy types, incorrect ESR prediction at the design stage may lead to problems. Hence, in this study, the ESR and construction cost are analyzed for each new renewable energy capacity to predict the ESR of photovoltaic (PV), building integrated photovoltaic (BIPV), geothermal, and fuel cell systems. Passive and active technology elements of the ZEB cases in Korea are analyzed, and by establishing a standard model with the average value of each case, the ESR is calculated for each new renewable energy capacity, and the calculation formulas are derived. The results indicate that for the PV and BIPV systems, the rate of ESR increases with the capacity (kWp) and is constant at 0.54% and 0.34%, respectively. However, for the geothermal system and fuel cells, the average ESR is 0.016% and 1.46%, respectively, but as the rate of ESR increase with the capacity (kW) gradually decreases, the calculation formulas are derived with a log graph.