Can Solar Panels Withstand Category 5 Hurricane?

The question comes up every now and again about how Solar Panels hold up in a Hurricane.

The short answer is, it depends. There is a lot of discussion about how NJ residents with roof top solar panels did very well during Hurricane Sandy. That was a Category 1 Hurricane however when it reached landfall and quickly downgraded to tropical force winds. You will find that in New Jersey the solar panels held up great.

However, what about Cabo San Lucas, Florida, the Antilles Islands who are prone to Category 5 Hurricanes with sustained winds of 165+ mph?

Research on solar panels results in the actual glass panels can withstand a great amount of external forces. Each manufacturer is a little different and it is important to ask for their specifications if you live in an area prone to powerful Hurricanes. Now, the panel itself itself is important, but what is equally important are the connections of the solar panels to your roof.

Typically, rails are attached to the roof via lag screws, and the panels are attached to the rails. Both of these connections must resist the uplift which is created in hurricane force winds.

An engineer will provide calculations on this uplift, which will determine the type of rail to be used, the spacing of the lag screw connections and the size of the lag screw. It may very well require spacing less then the spacing of your roof rafters or trusses. In that case, blocking is needed between the roof members. It is important the blocking is attached adequately to the rafters or trusses as they all transfer these uplift forces.

Ask the engineer what the required design wind speed in your area is. Here is something interesting as well. Many engineers simply use the uplift formula which is the slope of the roof, and the wind speed that travels over the roof. Solar panels create an additional force due to the fact wind gets trapped underneath the panel. If you live in Naples, FL, and want solar panels, work with the engineer. A safe bet would be to ask the engineer what spacing the connections of the rails require per the building code, and decrease that spacing by 20%. That should give you peace of mind that solar panels are on your roof AFTER a hurricane hits.

Now if your panels work when the grid is off, that raises a whole new set of questions. Ideally, solar panel owners should have the option to switch off the grid and run solely off a backup battery. This is something very worth asking your installer about. If you are tied into a grid that won’t allow you to create electricity from your solar panels, well, you are in the same boat everyone else is without electricity.