Solar panels ?

[MelTx]

  My dog dont know much about solar panels,and I know less than that...I thought there was a posting about my question but I cant find it...The only place I have to put solar panels is in a shady area.Will they still produce power with just the light or do they need full sun...The wind wont blow here in the summer for two months,zero wind....Maybe I could start on solar then.       MelTx

[hamlet]

I dunno, would you put a hydroelectric dam in the Sahara?  The only power I know of that's found in the shade is coal.  Sure, you can measue a few volts from a shady panel, but about all it's good for is running a voltmeter, weakly.

-hamlet

[Chagrin]

Solar panels are far too expensive to put in a shady area.

It might not seem like a lot of light difference but it certainly is.

[Jeff7]

The volts should remain about constant, but the amperage will go WAY down. Full sunlight, my prototype panel put out 2.2V at 3.2 amps. When a cloud passed over - just a regular little cumulus cloud, not some huge cumulonimbus - output was closer to maybe 0.2A if even that.

[BT Humble]

My array is on my shed roof, and in full sun I see about 20A at 24V.  On a cloudy/rainy day, that drops down to 1A or less.  

If you're going to invest in solar panels, it might be worthwhile to invest in a chainsaw too! ;-)

BTH

[ghurd]

Somewhere must have good sun.

Use longer wire to get the panels to the sun.

Most power comes between about 10:00 and 3:00, so don't worry TOO much about the first and last couple hours of sun.

G-

[Jeff7]

Ah, but using longer wire introduces resistance. Low voltage systems need thicker gauge wire. Here are some charts of wire gauges needed for various amperages, at different voltages, and the distances that you can run them.

[richhagen]

It is a tradeoff.  If you have to run 50% longer wire to get out of the shade where you will triple your amps it is probably worth it.  (or get a bigger chainsaw)  Rich Hagen

[ghurd]

Yes.

And remember the peak amps only happens for a few minutes, so even a 10% loss could be aceptable for the short time it will be that high, though I always like larger wire.

Also keep in mind the panel will have a peak power rating around 17 volts, so you will have a little extra voltage to play with.

The right controller can help too. I like Morningstars, they are mosfet controlled and typically have a forward Vdrop of 0.1 or 0.2 volts. Some others have are over 1 volt drop.  I suppose current has a little to do with the drop too.

G-