Please bolt the panel down, if wind picks it up and blows it off the roof it could easily kill someone.
thus the difference between the air speeds over the panel and under the panel in this case equals to the wind speed. To compare - Cessna wing loading is 15lb per square foot and it is generated at the minimum no-stall speed required by the FAA for general aviation of something around 70 miles/hour, and in that situation the speed difference between over the wing and under the wing is obviously significantly less than the 70 miles/per hour that wing moves through the air with. Thus it is pretty possible (to be sure one can just plug the numbers into any aerodynamics calculator on the web) that this panel at 8 square feet would generate multiple tens or even like 100lb+ lifting force at storm/hurricane winds of like 70 miles/hour and may pretty easy lift itself at the 30-40 miles per hour wind (which do happen on occasion in SF/BayArea). This is basically the same basic aerodynamics (Bernoulli speed difference) that tears buildings' roofs off in hurricanes.
Most obvious problem aircraft can fly upside down.
"{The upper flow is faster and from Bernoulli's equation the pressure is lower. The difference in pressure across the airfoil produces the lift.} As we have seen in Experiment #1, this part of the theory is correct."
Re-read my original comment - it is pretty much stating the same as the cited text above.
The link you posted refutes the "Equal Transit" Theory which is deriving the speed difference from the wing asymmetrical shape using very simple approach. Which has nothing to do with my original comment as i was applying the [correct according to Bernoulli law and your link] theory of pressure difference generated by airflow speed difference to airfoils without regard to whether they assymetrical (Cessna wing) or symmetrical (solar panel).
"The symmetric airfoil in our experiment generates plenty of lift and its upper surface is the same length as the lower surface. Think of a paper airplane. Its airfoil is a flat plate --> top and bottom exactly the same length and shape and yet they fly just fine."
Wings are angled into the wind. The curved shape primarily minimizes drag rather than generating lift.
As to hurricanes most roofs are sloped. Yes, faster moving air has lower pressure, but if you run the equation it's a fairly weak effect. So, it has little to do with stall speed.
So, you can work out max wind via historical data, but 85MPH is not going to be enough to move it over that lip. The skin effect around a building drastically reduces the forces involved.
So, saying any if the actual significant reasons to bolt it does haze zero influence on my objection.
And I am being serious here, if you notice to car rotated and got slightly lifted but not flipped into the air or moved very far. But most importantly, the wind is much stronger a few feet in the air vs 1 inch from the ground.
That's a when not if scenario waiting to happen.
But sure, bolt it down. Minimal effort vs minimal risk is something people do all the time. My point is the actual risk is very close to zero.
Yes, in a slightly different situation this would be an issue. But, wind is not magic fairy dust that can lift arbitrary loads.
Just stop with the flawed logic.
My point is the specific bad thing described is unlikely to happen. And sure I got a lot of knee jerk reactions but nobody actually did any kind of meaningful calculation demonstrating an issue.
Your sole argument is, historical wind speeds won't lift it. That is not realistic, naive and outright dangerous thing for which people actually get badly hurt or die.
But, I don't see you slowing down in this thread, so I doubt safety concerns will reach you.
Followed by a knee jerk reaction without any facts backing it up...
> That is not realistic, naive and outright dangerous thing for which people actually get badly hurt or die.
PS: Potted plants are often placed on the top of flat roofs with a lip and don't get tossed off it by the wind. The reason has to do with how the wind is deflected over the building and the obstructions around it. Often pushing them in opposite directions from the wind because of a giant counter rotating vortex of air. But, be happy with your inaccurate and over simplified model of how the world works.