The tech has on house size panels, less so on road/marine panels.Bit of both...those leaves were never going to just stay there...
I hoped the tech would have moved along by now. I know when I had solar fitted at home shade was an issue
The issue is that any array of panels will be influenced by the worst area of the panel, it will drag the rest of the array down, because they are all electrically connected.
For houses you can avoid this if you have shade by going for micro inverters - then each panel is independent and if one is shaded it doesn't drag down the others.
The other way is to have a controller that is smarter about MPPT. The problem is MPPT (Maximum Power Point Tracking) which tries to vary the current/voltage to give the highest power output for the conditions - once it finds the peak it tracks it - hence the name. But if part of the array gets shaded many MPPT controllers will just blindly follow that peak as the power dives. Some can be enabled to search for a new peak every few minutes - in ideal conditions this loses a bit of power as it does the search but in the real world it can often find a better peak to track. I've got this in the house array, but not sure I've ever seen one in portable system.
But yes, intuitively you'd expect to lose an amount of power equal to the amount of shade but in reality you lose a substantial amount from the panel in shade and all the ones in the same circuit.
