Solar panel question

Thanks for the replies.
Even with a background in electronics solar, for some reason, confuses me. Maybe I'm just over thinking it. I know everything I read prior to finally buying a system, and that was a lot, said shade will lower the output. And when I tested mine before I installed it it proved true, voltage stayed fairly constant but amperage dropped considerably. Maybe I just mis-understood what was being said in the other post about bypass diodes preventing loss of power if a panel is only partly shaded. I know that's not what I saw with mine.

Just about all panels are crystaline panels, either mono or poly, and will react the same way to shade. A tiny bit of shade causes a huge drop in output. Panels that are amorphous design are different. Shade and power are fairly linear. However, they're only about half as efficient and thus twice as large for a given watt rating.

HI,

I have a e-meter on my motorhome, and it shows that I use about 35 AH daily, just to run the refrigerator, CO and propane detectors. That is about what my 120 watt panel will put out in a day.

CHances are that if you had another 100 - 150 watt panel, you will see the battery is full on a daily basis, and not take time to watch how much the amperage goes up and down as each cloud goes by.

http://rvsolarelectric.com/ is a local RV supply place in Scottsdale AZ, and that is where I bought my pair of 45 watt solar panels back in 1994. Then it was a good price to spend $750 for the kit, with instructions, wire, and mounts.

Now you can mail order panels from many places, like this one. SunElec.com and get them for around $1 per rated watt. So installing a second panel is not that expensive anymore.

Fred.

With 2 parallel panels and one not in the shade you'll get the expected output from that panel.

Read Handy Bob's information especially about Q installers - don't consider shadows as they will return to buy more panels - sounds like what you posted.

Keith,
Kyocera is about as good as it gets, their frames are very strong. Your question pertains to the way solar panels work in general. It is my understanding that all of the individuals panels that make up the entire panel must be in the sun for maximum output. If some of the small panels are shaded, they actually act like a sponge and take away from the output of the rest. I installed my panels 6 inches off of the rood surface so that nothing on the coach roof could shade the panels.