SEBEpv – New digital surface model based method for estimating the ground reflected irradiance in an urban environment

• Published in: Solar energy Vol. 199; pp. 400 - 410
• Main Authors: Revesz, Michael, Zamini, Shokufeh, Oswald, Sandro M., Trimmel, Heidelinde, Weihs, Philipp
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 15.03.2020; Pergamon Press Inc
• Subjects: Algorithms; Alternative energy sources; Angular resolution; Bias; Building envelopes; Canyons; Climatology; Computer simulation; Digital surface model; Environment models; Facades; Fluxes; Irradiance; Irradiation; Modelling; Photovoltaic; Photovoltaic cells; Photovoltaics; Radiation measurement; Reflected radiation; Renewable energy; Roofs; Shading; Solar energy; Solar radiation; Street canyons; Thermal comfort; Three dimensional models; Urban environment; Urban environments; Reflected radiation; Photovoltaic; Modelling; Urban environment; Digital surface model; Solar radiation
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2020.01.075

[Display omitted] •New tool SEBEpv for estimating solar irradiance on building facades was developed.•SEBEpv was optimised for the ground-reflected irradiance in an urban environment.•Estimation of the ground-reflected irradiance was significantly improved.•SEBEpv is based on digital surface model (DSM) data for predictions in 3D space. Knowing the solar radiation fluxes inside an urban canyon is of interest for different purposes: e.g. urban climatology and studies of human thermal comfort and gaining relevance for future renewable energy generation in an urban environment using photovoltaic systems. For the latter, mainly rooftops are of interest, but studies started to extend towards the solar resources on building facades. However, the reflected solar radiation from the ground is either neglected or estimated using simplifications that lead to overestimation. SEBEpv (Solar Energy on Building Envelope – photovoltaic) is a new tool attempting to provide better estimates for the radiation reflected from the ground onto facades. It is primarily intended for the urban environment where the ground-view is very limited. SEBEpv delivers 3D results based on digital surface models of the environment. Furthermore, an optional PV model was added in order to address the simplified of estimation of reflected radiation when modelling photovoltaic (PV) yields. SEBEpv delivers quite good estimates for the solar radiation compared to the measurements. The simulated irradiance shows an RMSE of 28.7 W/m2 compared to the measured irradiance and has a bias close to zero. This is about half the RMSE shown by the predecessor tool SEBE. The measured total irradiation over two years shows a bias of about 7%, which is likely to be a result of the limited angular resolution of the shading algorithm. Overall, SEBEpv seems to be a promising tool, accounting for reflected radiation in urban environments.