We play softball on a field owned by a school. A large number (hundreds) of solar panels are being installed, 20’ or so away from and parallel to the foul lines. They’re about 20’ off the ground. As expected, foul balls are landing atop the panels. The first question is obvious.
What are the odds these balls are damaging the panels?
Secondly, when the installation is complete, and the system is up and running, would individual damaged panels be apparent to the operator?
Thx
Solar panels are rated to withstand a certain degree of hail damage. Typically this is 1" hail falling at 50 mph, but higher ratings are available.
So the first question is whether you live in a region with severe hail, where it’s more likely that hail-resistant panels would be installed.
If not, 1" @ 50 mph seems a bit borderline in comparison to a softball. On one hand, the softball is softer and its mass is spread out over a larger area (I know softballs aren’t especially soft as far as balls go, but they’re softer than ice). On the other, it’s more mass than a 1" hailstone. Speeds are probably comparable.
I’d lean toward it not being a problem due to the less concentrated nature of the impact and the fact that the panels will be overdesigned for impact tolerance (they should suffer no damage in a full hailstorm; it isn’t just a one-time impact). But it’s hard to be sure without testing.
I’m not sure what tools the operator has for detecting damage. It would be obvious if there was a lot of damage, but a few impacts here and there might not show up unless they can monitor individual panels.
Thx for info. To the extent this info is relevant, I’m in coastal Southern California. Secondly, they are called “softballs,” but they are anything but soft. They’re hard as a rock.
They’re not literally hard as a rock. They’re pretty hard, but (as @Dr.Strangelove said) softer than hailstones. Also softer than baseballs, for what it’s worth. Though those are also relevant, since the field probably isn’t used exclusively for softball.
Yeah, there’s a big difference between being truly hard as a rock vs. just being fairly hard. The leather covering will spread out a little bit on impact. The ice, much less so, especially at low temperatures.
And even for rocks, the hardness matters. You can throw a decent-sized rock at a tempered-glass car window with no damage. But a tiny piece of ceramic from a broken spark plug will shatter it. The ceramic is just that much harder, so the tiny impact from a sharp point applies much more pressure than an ordinary rock could.
That said, overall impact energy does play a part, and with a large enough mass you can damage the panel no matter how soft it is. But I don’t think a softball would reach that level.
Another factor would possibly be what angle the balls are striking the panels at.
I work for a company that installs and owns large arrays of ground-mounted solar panels (among other things). We are currently building such an array in a field adjacent to a football ground and a golf (pitch and putt) course. As the asset owner, we cannot tolerate the risk of balls entering our facility for a number of reasons, of which damage to the panels is only one. Danger to personnel during construction and security risk and risk of injury associated with people climbing the fence to retrieve balls are also important considerations.
For this reason we have installed high netting along the boundary with the sports facilities.
You also ask whether the operator would become aware of damage to a panel. That really depends on their asset management and maintenance regime. There are two ways such damage can become apparent. The first is through remote monitoring of the output from each inverter, which is compared to the expected output based on incident solar radiation and temperature. An unexpected shortfall in generation could be caused by physical damage, fouling, or shading. Secondly by visual inspection during a maintenance visit (possibly by drone in the case of a large array).