Abstract
PV panels are vastly used for sustainable electricity generation, while they can also help the environment by improving buildings’ energy consumption. The best placement for PV panels installation in buildings with flat roofs is the roof. When placed on a building's roof, PV panels affect the building's energy loads by shading the roof surface. However, the shading effect of PV panels could be different depending on the roof's thermal properties and surface materials. The combined effect of shading caused by PV panels and cool materials could significantly change the roof surface temperature, and the building energy demand. In light of the lack of studies considering this combined effect, the present study aims to evaluate the energy-saving effects of different roof materials covered with solar PV panels for a typical residential building in four cities with different climate conditions in Iran. Applying a simulation tool, Ladybug Tools have been utilized for determining the building energy loads and PV panels' power generation. The obtained results indicate that PV panels significantly affect the cooling load of the building, especially during peak times. The hottest city, Bandar-Abbas, benefits the most, with a maximum saved energy ratio (SER) of 3.4%, while the coldest city, Ardabil, has the least SER, 0.5%. Additionally, in cold and moderate climates, the highest SER occurs for the lowest R-value and solar absorption roof, while for hot climates, the highest SER occurs for the roofs with the highest R-value and the lowest solar absorption. Overall, the shading effect of PV panels becomes more significant when solar absorption is high, and the roof R-value is low. Despite the decrease in cooling energy load, PV panels might increase the heating load. Depending on the climate, this contradictory effect of the roof's thermal properties and PV panels shading should be considered in the design process of buildings.
Highlights
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Cities with hot-humid and cold climates have the highest and the lowest SER, respectively.
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PV shading is more significant on roofs with high solar absorption and low R-value.
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The effect of PV panels on heating load varies based on climate.
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Data availability
The datasets generated during and analyzed during the current study are available from the corresponding author upon reasonable request.
Abbreviations
- BIPV:
-
Building Integrated Photo Voltaic
- PV:
-
Photovoltaic
- R- value:
-
Thermal resistance
- S :
-
Solar absorption
- SER:
-
Saved Energy Ratio
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Vakilinezhad, R., Ziaee, N. Assessing the combined effect of PV panels’ shading and cool materials on building energy loads in different climates. Environ Dev Sustain 26, 16201–16221 (2024). https://doi.org/10.1007/s10668-023-03293-y
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DOI: https://doi.org/10.1007/s10668-023-03293-y