"Good Morning, Sunshine" or should we buy solar panels?

[pasdad1]

Originally Posted by cwk

OK. I am trying to learn here. I can see that there might be a little bit of shading from the A/C units. But, does that (what I think is) little bit of shading going to cause big problems? I admit, I do not understand the technology yet. Would you kindly explain? Thanks!

Panels are made up individual cells all wired in series. Each cell only puts out about 0.5v so a standard "12 volt" panel is typically made of 36 cells wired in series to produce a max open circuit voltage of near 18 volts. Because they are all in series, if even one cell has a shadow, its output drops to near zero, and blocks the voltage from the other cells, dropping the output of the entire panel to near zero. This is why many solar installations have multiple panels all wired in parallel .....this way if a panel output drops to near zero, the other panels without shading continue to produce full output.

[cwk]

Originally Posted by pasdad1

Panels are made up individual cells all wired in series. Each cell only puts out about 0.5v so a standard "12 volt" panel is typically made of 36 cells wired in series to produce a max open circuit voltage of near 18 volts. Because they are all in series, if even one cell has a shadow, its output drops to near zero, and blocks the voltage from the other cells, dropping the output of the entire panel to near zero. This is why many solar installations have multiple panels all wired in parallel .....this way if a panel output drops to near zero, the other panels without shading continue to produce full output.

It sounds like the old Christmas tree light strings from years ago. When one bulb burned out, the entire string went dark.

Thanks for the explanation. It almost seems like multiple, smaller panels in place of single large panels would work better. Time to keep researching.

[shaman52]

Here is how to avoid shading problems. Panels are 1.5 inches above heat pump. Added shading to rear bedroom, cooler temperatures, and help with rain noise in bedroom.

[cwk]

Originally Posted by shaman52

Here is how to avoid shading problems. Panels are 1.5 inches above heat pump. Added shading to rear bedroom, cooler temperatures, and help with rain noise in bedroom.

Very clever!


My concern would be wind getting under the panels and trying to lift them up and rip them out. What precautions did you add to prevent that possibility?

And, does that raise the overall height of the rig where it becomes an issue with bridges, tunnels, and overpasses?

[PJStough]

Originally Posted by cwk

Very clever!


My concern would be wind getting under the panels and trying to lift them up and rip them out. What precautions did you add to prevent that possibility?

And, does that raise the overall height of the rig where it becomes an issue with bridges, tunnels, and overpasses?

We have had two 200 watt panels on our roof for five years, and we added a third last December. We used 2" wide angle aluminum 3M 5200 Fast Cure and one screw per piece, and we have four pieces of angle aluminum per panel, and have never worried, or seen any sign that the panels were coming loose.

Our panels added two or three inches to the height of the motorhome, but still way lower than the air conditioners.

[shaman52]

Installation 3+ years ago with no problems. Never had a loose connection, very strong structurally with triangulalization. Adding 1.5" to RV presents no problem with height. Install was done by Starlight Solar in Yuma AZ. They have done hundreds of these types of installs.

[kustom]

cool thanks

[cwk]

Originally Posted by shaman52

Installation 3+ years ago with no problems. Never had a loose connection, very strong structurally with triangulalization. Adding 1.5" to RV presents no problem with height. Install was done by Starlight Solar in Yuma AZ. They have done hundreds of these types of installs.

Thank all of you for sharing.