Beginner solar / shed lighting

[Michael Aos]

I picked up a couple of Coleman 100W solar panels on sale / clearance at Sam's Club.

I'd like to set them up to power some dusk-to-dawn and maybe some motion-sensor lights on the sheds. Probably an interior light while I'm at it.

Any suggestions on specific batteries? DC lighting? I don't know if I even want to run an inverter 24/7.
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[RNeumann]

I’d skip the inverter and go with 12v DC lights to match the panels. The key is to find lights that use the least amount of power per lumen- typically LED is best. The cost analysis would have you buying lead acid batteries for this application. The other options for a fixed “non critical” application are simply higher in cost per life cycle.

To size the battery bank you will need to decide how long you want the lights on and how much power the panels make when you factor angle, sun vs shade and clouds, hours of daylight on the shortest day etc.

 

[Oaktree]

+1 on the 12v lights. I did something similar with a shed too far from the house to make running 110 practical. I just used an old car battery and some of those cheapie LED "driving lights" you can get at Walmart or any chain auto parts store. I'm just using it for interior lighting that's only used occasionally. Lights I'm using aren't bright enough to do any work by, but are fine if I just want to find something after dark which is all I wanted in the first place.
Never measured current drain, but I'd imagine a car battery would run LED lights overnight, your panel is bigger than the one I use, should be sufficient to recharge.

5 years later and the battery is still holding up (and it was one that I'd replaced in my wife's car).

 

[TnAndy]

Motion lights and an interior light won't draw much at all if LED.....you'll just need a single deep discharge battery plus some kind of charge controller. I use one to keep a battery on a piece of equipment trickle charged with a 40w panel. A $15-30 cheap one will do all you need, just make sure it shows battery condition (mine has 3 red led's to show state of charge on the battery)

Two 100w panels will produce 150-175w peak power, if you can mount them where they get good sun, say around a 40-45 degree angle, you'll produce 500-700 or so watt hrs/day on sunny days. Assuming your lights draw 20watts total, and burn 4 hours in the night (going to be hard to say on motion light), you're only using 80 watt/hrs per day, so you should have plenty of reserve to carry you thru cloudy days.

 

[Industrial Toys]

There are a bundle of cheap chinese solar controllers on E-Bay. I will probably buy one for a panel I have, for a shack up at our pond. I would probably put clockwork style timers on lights, just to prevent them from being left on.

 

[Alan W.]

There are a bundle of cheap chinese solar controllers on E-Bay. I will probably buy one for a panel I have, for a shack up at our pond. I would probably put clockwork style timers on lights, just to prevent them from being left on.

Be careful of the charge controller. I bought one that came with good reviews? It worked good for awhile, now it will only put about 8 volts to the battery no matter how much the panel is putting to it. But admittedly while it was working it was a sweet setup for my fence charger.