Instructables

Solar Panels in Parallel?

I know that you can wire solar panels together to combine the amps. But I've only ever seen this done with 2 identical panels.

Would there be any problem with wiring up 2 panels with different A values?

More specifically these 2 panels.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=390312612951&ssPageName=STRK:MEWNX:IT#ht_10141wt_1165


http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=320381449459&ssPageName=STRK:MEWNX:IT#ht_10175wt_1165

frollard3 years ago
so long as they output the same voltage in the same amount of light, they have equal potential and should each contribute what amperage they can at that voltage. If there is a discrepency or they are unbalanced, you'll want to add a low drop diode to each differing panel to prevent a reverse voltage on the outputs.
madmanmoe64 (author)  frollard3 years ago
I intentionally got two with the same rated voltage. I'll need some testing to figure out how close the real voltages are when in use, but I'll probably put diodes in anyway,

Thanks
iceng frollard3 years ago
And even then, the panel that has a higher voltage will shut the other 
panel down by reverse biasing the other diode.
Perhaps a load that pulls down one panel can start to use both. 
Now you don't need diode losses,  take them diodes out.
And when a light  small load only uses a part of a panel output, the remainder capacity will shunt over to the other panel and balance due
to the fact a panel acts as a resistor when over voltage is applied.

What I'm saying the panels can be wired parallel no diode.
If they are the almost the same they cannot hurt each other,
and when a load needs the dual current they will supply it together.

A
I'd put a diode anyway, as you can never trust anything to be exactly what it claims it is :).