Did you ever wonder whether the wind could affect your solar panel’s ability to generate electricity? Or whether your solar panels could be blown off the roof, and is there anything you can do to protect them from the wind?
Wind blowing over your solar panels cools them, and this adds to the efficiency of the output and, in some instances, can significantly improve your productivity. The mounting systems used to secure your panels will ensure they stay secure even during stormy weather.
Wind may not be something you have considered, so let’s look at the wind and it relates to your solar panels:
- Wind affects solar panels
- Wind effect on solar radiation
- Wind speeds on solar panels
- Detect wind and protect your solar array
Understanding the effects of the wind on your solar PV system and how it can positively and negatively influence their performance is critical to their installation and performance.
How Does The Wind Affect Solar Panels?
Solar panels are electronic devices and, like most electronic devices, are most efficient when operating at cooler temperatures. This is why solar panels typically are as efficient in warmer climates as in moderate to temperate ones.
The electronics generate heat, and heat causes electrical resistance, reducing efficiency, but when the panels are cooler, they are more efficient with power generation.
As the wind blows over the panels and around them, the temperature inside the panels and on the surface is reduced, increasing the voltage generated. So if you thought that your PV system would be less efficient because of wind, think again!
Is Solar Radiation Affected By The Wind?
The sun’s radiation is affected by the atmospheric temperature and humidity, while wind speed was found to have little effect (if any) on solar radiation.
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. Factors like clouds, rain, and humidity affect the air temperature, which has a more significant influence on solar radiation than the wind itself.
How Much Wind Force Do Solar Panels Experience?
Wind force exerted on solar panels will vary based on average wind conditions, and these will be considered. Still, in many cases where the wind has created lift under the panels, it is often the roof itself that is damaged and not the panels.
Solar panels will experience wind force that pushes down on the panel from above and pushes up from the gap underneath the panel between the panel and the roof. This can create turbulence against the ballasts and weights designed to resist the wind.
The PV industry has set codes and standards to ensure that solar panel installations meet the required standards for that area and are not subject to excessive ballast pressure exerted on the panels by the wind.
Panels are usually mounted at least 11″ from the roof edge to reduce and prevent excessive wind loading.
During severe storms like hurricanes and tornados, it is more often the roof itself that is ripped off, taking the solar panels with it, and very seldom do the panels themselves come loose from the mounting racks.
What Wind Speed Are Solar Panel Installations Rated For?
The standard rating for wind speed on installed solar panels is 140mph, and in areas prone to hurricanes and tornadoes like Florida and Ohio, solar panels are rated to withstand winds of 170mph.
To achieve this, the mounting systems and supporting roof structures may need to be reinforced to handle both the weight of the array and the potential wind forces that the array will be exposed to during the annual weather cycles.
Solar panels are very resilient to severe weather, and even severe hail often doesn’t damage them. A severe hailstorm at the National Renewable Energy Laboratory in Golden, Colorado, only damaged one panel out of 3000 installed on a large array.
Why The Mounting System Is The Main Consideration For Wind Resistance
Ground mounting systems can withstand greater wind force, while a solid roof and mounting system will perform well under all manner of windy conditions.
The type of mounting system, materials used, and installation quality are the main factors when considering the impact of wind on your solar installation. If you have a superior mounting system that is poorly installed, you run the risk of wind damage.
Truth be told, before you install your panels, check your roof for wind damage as this will indicate the roof quality and its resistance to the wind, and make sure your roof is in top condition before installing a solar PV system.
How A Southerly Wind Can Increase Efficiency Significantly
A recent study in the UK showed that southerly wind increased solar output by 20%-43%!
This was because solar parks and installations usually face South in the Northern Hemisphere, with the panels pointed skyward. This is to maximize solar exposure throughout the day.
Heat is created between solar radiation and electricity generation, causing efficiency to drop. When a southerly wind blew over the panels, the cooling effect was more significant on the southern side of the panels, thus increasing efficiency.
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, and using wind detectors and wind deflectors to assess wind conditions will help.
Wind deflectors, when properly installed, can add more wind downforce over the panels, reduce lift, cool the panels down, and add to efficiency. Wind detectors will give you data around wind speed, but because solar panels are outside, shielding them from the wind is virtually impossible.
Deflectors are designed to minimize turbulence and create smooth airflow over and around the panels reducing lift and improving downforce. Deflectors would be advisable if you live in an area known for strong winds.
The best defense against the wind aside from the array direction and deflectors (if needed) is a suitable and durable mounting rack and materials and a properly installed system.