# Experimental Investigation of Wind Loads on Roof-Mounted Solar Arrays

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## Abstract

**:**

## 1. Introduction

## 2. Wind Tunnel Tests Experimental Setup and Measurements

#### 2.1. Model and Instrumentations

^{2}. The five rows of arrays were symmetrically mounted on the roof, with a row space of 1.0 m and setbacks of 2.16 m from the edge of the roof. To investigate the influence of the tilt angle and parapet on the arrays’ wind loads, two module tilt angles (5° and 10°) and four parapet heights (0 m, 0.9 m, 1.2 m, 1.5 m) were set in the wind tunnel tests.

#### 2.2. Terrain Simulation

## 3. Data Processing

## 4. Results and Discussion

#### 4.1. 0° and 180° Wind Directions

#### 4.1.1. Effect of Parapet Height

#### 4.1.2. Effect of Tilt Angle

#### 4.2. 90° and 270° Wind Directions

#### 4.2.1. Effect of Parapet Height

#### 4.2.2. Effect of Tilt Angle

#### 4.3. Oblique Wind Direction

## 5. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 1.**(

**a**) The facade diagram of low-rise building with parapet, and (

**b**) photographs of model arrays mounted on the roof, showing the upstream terrain.

**Figure 2.**Layout of roof-mounted arrays with row numbers, wind direction and pressure taps, # is the unit of Row.

**Figure 4.**(

**a**) Mean velocity and (

**b**) turbulence intensity profiles of measured terrain and open terrain given in GB 50009-2012. Data points are experimental measures, whereas the solid lines are GB profiles with $\alpha $ = 0.12.

**Figure 5.**Contour plot of net pressure $\Delta {C}_{p}$ on module surface at (

**a**) 0° and (

**b**) 180° azimuth with tilt angle of 10° and parapet height of 0 m.

**Figure 6.**(

**a**) Mean (${C}_{p,mean}$) and (

**b**) standard deviation (${C}_{p,RMS}$) of area-averaged pressure coefficients for units in five rows for wind direction of 0° with tilt angle of 10° and parapet height of 0 m.

**Figure 7.**(

**a**) Skewness and (

**b**) kurtosis of area-averaged pressure coefficients for units in five rows for wind direction of 0° with tilt angle of 10° and parapet height of 0 m.

**Figure 8.**(

**a**) Maximum (${C}_{pi,\mathrm{max}}$) and (

**b**) minimum (${C}_{pi,\mathrm{min}}$) peak pressure coefficients for units in five rows for wind direction of 0° with tilt angle of 10° and parapet height of 0 m.

**Figure 9.**(

**a**) Positive (${g}^{+}$) and (

**b**) negative (${g}^{-}$) peak factors for units in five rows for wind direction of 0° with tilt angle of 10° and parapet height of 0 m.

**Figure 10.**(

**a**) Mean (${C}_{p,mean}$) and (

**b**) standard deviation (${C}_{p,RMS}$) of area-averaged pressure coefficients for units in five rows for wind direction of 180° with tilt angle of 10° and parapet height of 0 m.

**Figure 11.**(

**a**) Skewness and (

**b**) kurtosis of area-averaged pressure coefficients for units in five rows for wind direction of 180° with tilt angle of 10° and parapet height of 0 m.

**Figure 12.**(

**a**) Maximum (${C}_{pi,\mathrm{max}}$) and (

**b**) minimum (${C}_{pi,\mathrm{min}}$) peak pressure coefficients for units in five rows for wind direction of 180° with tilt angle of 10° and parapet height of 0 m.

**Figure 13.**(

**a**) Positive (${g}^{+}$) and (

**b**) negative (${g}^{-}$) peak factors for units in five rows for wind direction of 180° with tilt angle of 10° and parapet height of 0 m.

**Figure 14.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum peak pressure coefficient (${C}_{pi,\mathrm{max}}$), (

**d**) minimum peak pressure coefficient (${C}_{pi,\mathrm{min}}$), (

**e**) positive peak factor (${g}^{+}$), (

**f**) negative peak factor (${g}^{-}$) within a row of 11 panels for wind direction of 0° with tilt angle of 10° and parapet height ($h$) of 0 m, 0.9 m, 1.2 m and 1.5 m.

**Figure 15.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum peak pressure coefficient (${C}_{pi,\mathrm{max}}$), (

**d**) minimum peak pressure coefficient (${C}_{pi,\mathrm{min}}$), (

**e**) positive peak factor (${g}^{+}$), (

**f**) negative peak factor (${g}^{-}$) within a row of 11 panels for wind direction of 180° with tilt angle of 10° and parapet height ($h$) of 0 m, 0.9 m, 1.2 m and 1.5 m.

**Figure 16.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum (${C}_{pi,\mathrm{max}}$) and (

**d**) minimum (${C}_{pi,\mathrm{min}}$) peak pressure coefficients for units in five rows for wind direction of 0° with tilt angle of 5° and parapet height of 0 m.

**Figure 17.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum (${C}_{pi,\mathrm{max}}$) and (

**d**) minimum (${C}_{pi,\mathrm{min}}$) peak pressure coefficients for units in five rows for wind direction of 180° with tilt angle of 5° and parapet height of 0 m.

**Figure 18.**Contour plot of net pressure $\Delta {C}_{p}$ on module surface at (

**a**) 90° and (

**b**) 270° wind direction with tilt angle of 10° and parapet height of 0 m.

**Figure 19.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum (${C}_{p,RMS}$) and (

**d**) minimum (${C}_{pi,\mathrm{min}}$) peak pressure coefficients for units in five rows for wind direction of 90° with tilt angle of 10° and parapet height of 0 m.

**Figure 20.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum (${C}_{pi,\mathrm{max}}$) and (

**d**) minimum (${C}_{pi,\mathrm{min}}$) peak pressure coefficients for units in five rows for wind direction of 270° with tilt angle of 10° and parapet height of 0 m.

**Figure 21.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum peak pressure coefficient (${C}_{pi,\mathrm{max}}$), (

**d**) minimum peak pressure coefficient (${C}_{pi,\mathrm{min}}$) of a row of 11 panels for wind direction of 90° with tilt angle of 10° and parapet height ($h$) of 0 m, 0.9 m, 1.2 m and 1.5 m.

**Figure 22.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum peak pressure coefficient (${C}_{pi,\mathrm{max}}$), (

**d**) minimum peak pressure coefficient (${C}_{pi,\mathrm{min}}$) of a row of 11 panels for wind direction of 270° with tilt angle of 10° and parapet height ($h$) of 0 m, 0.9 m, 1.2 m and 1.5 m.

**Figure 23.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum (${C}_{pi,\mathrm{max}}$) and (

**d**) minimum (${C}_{pi,\mathrm{min}}$) peak pressure coefficients for units in five rows for wind direction of 90° with tilt angle of 5° and parapet height of 0 m.

**Figure 24.**Contour plot of net pressure $\Delta {C}_{p}$ on module surface at 45° wind direction with tilt angle of 10° and parapet height of 0 m.

**Figure 25.**(

**a**) Mean (${C}_{p,mean}$), (

**b**) standard deviation (${C}_{p,RMS}$), (

**c**) maximum (${C}_{pi,\mathrm{max}}$) and (

**d**) minimum (${C}_{pi,\mathrm{min}}$) peak pressure coefficients for units in five rows for wind direction of 45° with tilt angle of 10° and parapet height of 0 m.

**Figure 26.**Critical wind directions for the maximum and minimum peak pressure coefficients at measured locations for arrays with tilt angle of 10° and parapet height of 0 m.

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**MDPI and ACS Style**

Yao, J.; Tu, Z.; Wang, D.; Shen, G.; Lou, W.
Experimental Investigation of Wind Loads on Roof-Mounted Solar Arrays. *Sustainability* **2022**, *14*, 8477.
https://doi.org/10.3390/su14148477

**AMA Style**

Yao J, Tu Z, Wang D, Shen G, Lou W.
Experimental Investigation of Wind Loads on Roof-Mounted Solar Arrays. *Sustainability*. 2022; 14(14):8477.
https://doi.org/10.3390/su14148477

**Chicago/Turabian Style**

Yao, Jianfeng, Zhibin Tu, Dong Wang, Guohui Shen, and Wenjuan Lou.
2022. "Experimental Investigation of Wind Loads on Roof-Mounted Solar Arrays" *Sustainability* 14, no. 14: 8477.
https://doi.org/10.3390/su14148477