Joining solar panels together that have mismatched Watts

Lloydy

Is it okay to join solar panels in a parallel array that have mismatched Watts (ie a 20W + 10W panel) providing the Maximum Power Voltage (MPV) of each panel is the same?

Any potential problems?

Thanks

icarus

Re: Joining solar panels together that have mismatched Watts

As long as the rated voltages are close ~1/2v there should be no problem in parallel.

T.

BB.

Re: Joining solar panels together that have mismatched Watts

Pretty much you can parallel panels with similar Vmp (withing ~10% or less miss-match).

And you can put in series panels that have their Imp withing ~10%.

If the voltage or current are more than 10% difference, you will lose power/efficiency.

Paralleling panels--once you get more than two panels in parallel--you should put a fuse in series with each panel (or string if more than one panel in series). Placing 3 or more panels in parallel stings can supply short circuit current that exceeds the current rating of the panel in the case one of the panels/wires gets a short circuit.

Probably more of an issue for larger panels (bigger than 10-20 watts).

In general, paralleling lots of small panels is really a pain. Lots of wire connections and mounting hardware. Many times, it is better to get one large 100 watt panel than to parallel 10x 10 watt panels together.

-Bill