Reinforced Front Solar Panel Cracking - check yours!

[gklott]

We thought we had solved the front solar panel failure mechanism when we reinforced our front solar panel 10 months ago. Turns out that was not an adequate solution.

Hard to believe, but we were washing our trailer, including the roof.

We discovered that our front solar panel glass has shattered all around the edge at the frame. See attached. We wash our solar panels before departing on our trips, and this cracking was not present during our July/August trip. We just returned from another trip to visit family in Florida.

Suspect that the wind and resulting vibration is just too much for any solar panel mounted so close to the trailer's leading edge. That's why GoPower specifies that you must mount these panels at least 3 ft. back from the front roof edge.

Since a similar reinforcement is part of the ETI recommended fix, we recommend that anyone with a 19E or 21NE and a front mounted solar panel check their panel's glass for similar cracking.

We are removing our front panel today. We don't feel safe traveling with this new finding. We've contacted ETI. They have been helpful with our daughter's 21NE front solar panel failure. We hope ETI will respond similarly with our issue and recommended way forward soon.

73/gus

[Centex]

Well, darn, Gus, but thanks for sharing this important update.

Are you suspecting that there's a very low-pressure area created close-behind the front of the trailer with the result that the 'uplift-force' on the 'field' of the panel is causing the glass to deflect to its breaking point in spite of the (now) rigid frame?

Seems the point of failure has been moved from the frame to the next weakest link in the system.

[MVA]

Fortunately, the solar panel glass is now the weak point and not the trailer roof.

Stress fields unfortunately do not go away; they are just transferred and dispersed. Appears that the mounts are very rigid (that is good!) but the aerodynamic conditions of the front mounted panel are causing flexing of the panel glass with the stress maximum at the glass edges. This is an unfortunately an example of how dynamic conditions are not equivalent to static conditions. I am not sure if ETI understands this difference.

[Centex]

IF the force causing the damaging stress is indeed due to an aerodynamic phenomenon such as a 'low pressure area' it might be possible to make that force and related stress 'go away' by use of 'spoilers' to alter the aerodynamics. Not necessarily easy to design, fabricate, or intuitively predict the outcome.

'Tis a challenge indeed given other things on the roof which preclude simple relocation of the panel out of the area of aerodynamic-related forces which are 'PV-panel unfriendly'.

[gklott]

Originally Posted by Centex

Well, darn, Gus, but thanks for sharing this important update.

On the positive side of this discovery, we now have a clean front roof that was under the front solar panel! Plus, we prevented another crisis when taking our next trip.

Originally Posted by Centex

Are you suspecting that there's a very low-pressure area created close-behind the front of the trailer with the result that the 'uplift-force' on the 'field' of the panel is causing the glass to deflect to its breaking point in spite of the (now) rigid frame? Seems the point of failure has been moved from the frame to the next weakest link in the system.

I doubt we will know the real cause. It is probably everything - vibration, pressure, flexing,... The cracking around the entire perimeter was about an 1" to 1-1/2" into the glass.

We've contemplated how to replace this panel, but there is no room up front. As shown, to locate any panel at least 36" from the front edge, the placement starts right at the plumbing vent. A panel would cover the Maxxfan and the bathroom vent fan.

We have our rear panel for charging while driving. We also have a Lensun 200W portable. Those will do for now.

73/gus

[Centex]

Originally Posted by gklott

On the positive side of this discovery, we now have a clean front roof that was under the front solar panel! Plus, we prevented another crisis when taking our next trip.

Gotta love the person who can turn lemons into lemonade, kudos for the attitude!

[MyronL]

I had put a camera attached to the AC and drove a few miles before attaching my 190 solar panel up on the rear. The vibrations recorded there were a significant surprise. Think now I will add a strip of cushion to my angle frames.

https://youtu.be/X8tyU-2wqqo

[Perry Butler]

There is tremendous wind in the first three feet of the roof. While adding an angle will help there is still a span of 59" to vibrate.

Opinion:

I would either:

• remove the panel to sell or store for future use
  
  
• use two brackets front and two rear to shorten the span to 20" between brackets. The brackets would be attached using at least 10 square inches of VHB tape.

I would bolt, not tape, the brackets to the panel (you may have to drill a hole). Properly prepare your roof before attaching.

Enjoy,

Perry

[dstreight]

All very interesting and pertinent data! Keeping an eye on my front and back roof top solar array on our 15A!

[gklott]

ETI responded to our email. They agreed to repair everything, and we should receive the new fix shortly. ETI customer service remains excellent on all the items we've had to deal with.

73/gus

[Centex]

That's excellent news, Gus, thanks for sharing!

Taking that to mean you're going to be reinstalling a front panel, we'll be interested to follow that and any differences in the detailing.

[Dave Walter]

Seems to me that a flexible panel attached directly to the front portion of the roof may perform better than the elevated rigid panels.

[sjnuss]

Hi Gus.

Did they happen to mention anything about the "fix" they were supposed to develop for the front panel issue?

Steve