Net zero proximity index and techno-economic analysis of BIPV for zero energy and zero emission buildings

초록

The objective of this study was to develop a universal building assessment framework analyzing the techno-economic feasibility of a building as a zero-energy and zero emission building (ZEB). The study was conducted on a university building located in Seoul to evaluate the feasibility of converting it into ZEBs of three different standards by the US Department of Energy (DOE) and Energy Performance of Buildings Directive (EPBD) of EU. Energy performance index (EPI) and site energy utilization intensity (EUI) were employed to calculate the renewable energy fraction (RE) which shows the feasibility of achieving ZEB status. However, there are numerous ZEB definitions and their regulated portion of site EUI widely vary, making it difficult to know upon what ZEB standard the building is being assessed. Therefore, the net zero proximity index (NZPI) was newly proposed to benchmark various ZEB standards against the true meaning of zero-energy building. Additionally, the levelized cost of electricity (LCOE) of building-integrated photovoltaics (BIPV) of ZEB was calculated for the economic evaluation. Multiple cases involving various combinations of BIPVs over a wide price range presented high initial investment costs mainly due to wall and window BIPVs. The LCOE of the BIPV system was between 0.117 and 0.348 $/kWh.Insomecases,whereachievingZEBstatusrequiresadditionalground-mountedphotovoltaics(PV)nearby,LCOEincreasedbyafactorof1.5-7.Consideringthatutility-scalestandalonesolarPVisexpectedtoreach0.036$/kWh by 2027, higher efficiency, reliability, and lower costs, along with improved transparency for window BIPV will be essential for economically viable ZEBs.

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