Think of your vehicle windshield, which also has an upward tilt. How would it be if it wasn't cleaned for a week? A month? After three months? The dirt layer would be significant. Silfab, a top solar panel manufacturer, recommends cleaning panels at least 2-4 times a year.

Again think of your vehicle, how clean is it after it rains? The rains in SoCal are just not strong or long enough to get the dirt layer off.

Pressure washing may be convenient and expedient, but it is not recommended for anything that has a coated surface, including solar panels, because the force of the pressure can degrade the coating.

Yes. Birds flying around panels, and bird droppings, is usually a tell-tale sign that they are nesting underneath the panels, or at least spending time there. Unfortunately, solar panels provide the perfect protection for defenseless birds such as pigeons, because the 3-6 inches between the roof and panels is large enough for them to fit into, but small enough to deter birds of prey. Due to this, we recommend installing our mesh screens.​

Similar to vehicle paint, solar panels have a coating called ARC, or Anti Reflective Coating, which provides a layer of protection from the elements. Because of this coating, solar panels should not be cleaned the same way as regular glass, they should be cleaned with the same care as vehicle paint, which also has a coating. Read more on brushes.

The common mistake in deciding whether or not to clean solar panels, is to base that decision solely on efficiency. One might conclude that since efficiency has not degraded much, cleaning is not really needed. It happens to be though, that efficiency is just 1 out of 4 key reasons to regularly clean panels. I often compare cleaning solar panels with cleaning vehicles. Read more on cleaning regularly.

If you search whether it is safe to walk or sit on solar panels, you might see conflicting answers. The Google AI says don't do it, whereas other search results say it is ok, provided you're light or careful enough. Then we see various Youtube videos of companies cleaning panels or installing mesh screens, who sit on the panels throughout the installation (see below picture). So what is the truth? Read more on solar panels.

Of course, just like one can clean their own vehicle. The key difference though, is that cleaning panels require climbing onto the roof while cleaning on a roof angle, which is inherently dangerous. Another key difference is that when cleaning a vehicle, most of the vehicle surface is within reach without the need for any tools. Read more on self-cleaning.

A valid concern for those with roof tiles is, whenever someone goes onto the roof, will they crack any tiles while walking on them? The short answer is, it depends. An older tile would be more susceptible to cracking than a newer one, including any previous stress that could have resulted in micro-cracks. At the same time, how one walks on the tile makes a big difference. Read more on tile roofs.