Solar panels by the nature of their technology are heavily exposed to the environment and extreme weather conditions.  Often they are placed in open fields and rooftops where they can be exposed to wind, lightning, and hail.  Covering them with a protective cover does not make sense because you will also block the sunlight from striking the Photo Voltaic Cells on the panel, thus making it far less efficient. 

Design

Solar Panels are designed to withstand hail up to a certain size and impact speed.  They are protected by a tempered glass to avoid damage to the solar cells themselves.  A standard panel can withstand hail up to 1 inch in diameter at speeds up to 52 miles per hour!  Solar panel design undergoes rigorous testing to ensure this kind of durability over time.  Many measures are put into place when manufacturing a panel for use.  ISO, UL, IEC/EN, and CSA are just some of the certifications and standards that are used to qualify solar panels.

 

Materials

Different materials have been tested for use to protect solar panels.  Tempered glass, acrylic, and thin film panels are ideal for extreme weather conditions.  Thin film panels can flex and will not crack as easily as other designs.  The energy is distributed evenly across the surface helping to keep the panel intact under impact and pressure extremes. 

Insurance

It is also wise to purchase insurance for your solar system if you know that it will be subjected to extreme weather conditions.  Homeowner's insurance can also cover the expenses related to solar panel damage on your home. 

Testing

Many university tests have been conducted to study the strength and durability of solar panels.  The best solution is to protect the delicate interior of the panel with a clear glass or one of the materials mentioned above.  These tests will fire small steel pellets at the panels to simulate hail storms and other forms of impact.  The outer shell or protective coating of the panel can only withstand hail of a certain size and velocity.  That being said, insurance can be a very handy resource when installing panels in areas that are prone to hail.  Solar panels designed to International standards can withstand hailstones traveling at 50 miles per hour.  Newer materials are being tested that boast they can withstand impacts up to 250 mph! 

Implementation

The terminal velocity of a hailstone with a diameter of 8 centimeters is 110 mph.  Terminal velocity is the free fall speed of an object to the Earth’s gravitational pull with no other acceleration forces at play.  Another factor of forces and engineering is the impact angle of an object.  If an object strikes a surface at a direct 90-degree angle, the impact will have more force.  Solar panels are in most cases installed at an angle to better capture the suns light.  Panels in the northern hemisphere are inclined at an angle pointing towards the equator where the sun’s light is the strongest, and panels in the southern hemisphere are tilted accordingly as well.  Due to this phenomenon of sun light, panels can withstand impact forces quite well. 

In summary, the materials that are used as a protective coating are tested to size up against extreme weather conditions.  Solar panels are a type of equipment that will be heavily exposed to all kinds of outdoor weather conditions.  Protection from extreme temperatures, winds, and impact forces are taken into account when solar panels are manufactured.  The best way to protect your panel is to study the different materials being used to protect them, and consider purchasing insurance in the case that they may be exposed to reoccurring impacts.  You will also want to make sure that the company installing these solar panels knows which panels to select, and such experts can be found at http://bobheinmillersolar.com.

Featured images:

The writer, Nick Quinlan, is currently a student of environmental sciences who uses freelance writing on related subjects to help supplement his income and maintain his education. To learn more about Nick you can visit on Google+.