Environmental crises have considerably increased the utilization of renewable energy sources in the electricity grid. The quick rise in photovoltaic (PV) installations has aroused more research interest in efficiency improvement in recent years. Now, even one percent more gain is of crucial importance for sustainable energy development. Here will be shown the significant impact of wind speed on the total production of electricity.
We will consider how the wind might impact your solar panels' capacity to produce electricity or whether your solar panels could be damaged.
How Does the Wind Affect Solar Panels?
Solar panels are electronic devices and, like most electronic devices, generate heat when the PV panel absorbs solar irradiance. A minor part of it is converted into electrical energy, and the rest is converted into heat energy. Fundamentally, heat causes electrical resistance, reducing efficiency, but when the panels are cooler, they are more efficient.
Typically, a temperature increases of 1 °C causes between a 0.14% and 0.47% reduction in relative efficiency, depending on the type of PV panel installed. You can refer to Figure 1 to find AE solar Coefficient.
Figure 1: The Temperature Ratings of AE510ME-T150BD
The experimental results showed that wind flow can improve heat convection on the surface of the PV panel. Hence, an operating temperature decrease; especially during the peak sun hour, will increase PV productivity. Therefore, when the operating temperature of the PV panel decreases, the voltage generated will increase with the output power.
For instance, a recent study in Westmill Solar Park, Oxfordshire showed that in the northern hemisphere, PV arrays are south-facing. Consequently, southerly winds will increase solar output by 20%–43% and the solar panel will generate more electricity when a greater proportion of the panel surface is exposed to southerly winds.
Is Solar Radiation Affected by The Wind?
The wind is the result of the heating and cooling of the Earth, which relates to the influence of the sun’s heat on the air and surface of the planet. Wind speed has little influence on solar radiation, which is directly proportional to the atmospheric temperature while it is inversely proportional to the relative humidity. Consequently, the wind does not increase solar irradiance effectively. In other words, appropriate wind can increase just PV efficiency.
What is wind load and how does it affect the solar PV modules?
The wind load is defined as the exerted load which flows on the building (or even the solar PV modules).
This effect is divided into the loading caused by the wind pressure and the wind suction. The first influences the wind-facing side of the building and the second on the side opposite to the wind.
What wind speed are solar panel installations rated for?
Solar panels from manufacturers are rigorously tested to ensure they are engineered to withstand wind forces that push down on the panel from above and push up from the gap underneath the panel.
The PV wind load rating is especially important to determine how the panel can hold up in an extreme storm. The wind load is directly related to wind speed (Figure2) and measured in pascals(N/m2), which is a unit of pressure measurement. Most AE solar panels are manufactured to withstand up to 2,400 pascals, as shown in Figure3.
Figure 2: Wind Load vs Wind speed
(Source Wind Load vs Wind speed, The engineering toolbox)
Accordingly, the wind load should be calculated to ensure that your solar panels are securely mounted. Also, the mounting structure strength to handle both the weight of the array and the potential wind forces is significant. Generally, manufacturers provide manual instructions that must be considered for safe installation.
Figure 3. Mechanical and design specification of AE510ME-T150BD
How do you protect solar panels from the wind?
Knowing the wind conditions and direction can assist when installing the panels to reduce wind exposure. Wind detectors to assess wind conditions will help. Moreover, wind deflectors when properly installed, can add more wind downforce over the panels, reducing lift, cooling the panels down, and adding efficiency.
Author: A.M. Rayyan
References:
- https://www.hindawi.com/journals/ijp/2019/8369231/#:~:text=It%20is%20due%20to%20the,radiation%20increases%20the%20air%20temperature
- https://www.solar.com/learn/can-my-solar-panels-withstand-a-hurricane/#:~:text=Most%20solar%20panels%20are%20manufactured,to%20their%20different%20solar%20laws
- https://www.sciencedirect.com/science/article/abs/pii/S0038092X20303303?dgcid=author
- https://www.solar.com/learn/how-do-wind-and-humidity-affect-solar-panel-efficiency/