Shading example.png
Project data
Authors H. T. Nguyen
Joshua M. Pearce
Status Designed
Instance of Photovoltaics
Export to Open Know How Manifest
Page data
Type Project
Keywords shading losses, solar photovolatic potential, pv, Photovoltaics, gis, osat, open source, grass
SDGs Sustainable Development Goals SDG07 Affordable and clean energy
SDG11 Sustainable cities and communities
Published by Joshua M. Pearce
Published 2012
License CC BY-SA 4.0
Affiliations MOST
Page views 232
Location data
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Location Michigan, USA

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Recently several algorithms have been developed to calculate the solar photovoltaic (PV) potential on the basis of 2.5D raster data that can capture urban morphology. This study provides a new algorithm that (i) incorporates both terrain and near surface shadowing effects on the beam component; (ii) scales down the diffuse components of global irradiation; and (iii) utilizes free and open source GRASS and the module r.sun in modeling irradiation. This algorithm is semi-automatic and easy to upgrade or correct (no hand drawn areas), open source, detailed and provides rules of thumb for PV system design at the municipal level. The workflow is pilot tested on LiDAR data for 100 buildings in downtown Kingston, Ontario. Shading behavior was considered and suitable roof sections for solar PV installations selected using a multi-criteria objective. At sub-meter resolution and small time steps the effect of occlusion from near object was determined. Annual daily horizontal irradiation values were refined at 0.55m resolution and were shown to be lower than those obtained at 90 m by 30%. The robustness of r.sun as capable of working with different levels of surface complexity has been confirmed. Finally, the trade off of each computation option (spatial resolution, time step and shading effect) has been quantified at the meso scale, to assist planners in developing the appropriate computation protocols for their regions.

H. T. Nguyen and J. M. Pearce, "Incorporating Shading Losses in Solar Photovoltaic Potential Assessment at the Municipal Scale" Solar Energy 86(5), pp. 1245–1260 (2012). DOI Free and open access

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