Solar at its Best

RoyB,
From your previous posts it looks like you need to replace about 100Ah a day. Easily doable with modest solar (~300 watts) and then no more worries about gen run times.

How can you tell they are 12V panels? It looks like to me that the two panels put together are wider than the height. Two 12V 140 watt panels side by side would be about 6" narrower than the overall height making it a 280 watt system. Two 24V 235 watt panels side by side would be about 15" wider than the overall height making it around a 470 watt system? Just an observation but I'm sure I messed up on my math somewhere.

No doubt about it... that's pretty cool!

Living off your panels?

Depends on your parasitic draw. My old rig has virtually zero, so I stand to gain a lot from just 120W. Of course... this is all predicated on your location. There's a reason Sheble Aviation has it's flight school in Bullhead, AZ. They can keep their Cessna trainers in the air just about 365 days a year. Note they didn't choose a location in Washington state.

I think systems like this are good for those who have run out of roof real estate. Otherwise, I'd prefer the panels flat on the roof. They are less visible and thus less of a target for thieves that way.

And if you can't completely live off the panels... but you can shave off an hour of generator time in your campsite next door to MINE...

then I'm good with your 120W solar system.

Nice set up!

We could live off our 230w panel even with only morning sun.

Hi RJ,

There are commercial tracking units available, but they are costly (as in more than the cost of extra panels), so it just doesn't make economic sense.

RJ - I thought I could add too haha... Unfortunately they measure their solar panels at the SUN output. Like probably at the 18VDC level... if this is 18VDC panel and produces around 6.6AMPS then it would be called a 120WATT PANEL.

By the time the solar controllers get the 18V down to what we can use which is 12VDC then you have something alot less than 120WATTs of usable power. More like 12.3VDC at 6AMPs is only 74WATTS... So where did the 46WATTS sneak off too...

At least that is what I understand about how it works...

Roy Ken

Quote:
What can you do with just over 100WATTS of free power... You sure can't live off the panels alone.
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Jealousy will get you nowhere either !
100 watts ?? If I can add, its well over 200 watts !

Maybe you can't but many can, including me.
But you need sun all day. So keep in mind that most of these elaborate solar setups are mainly for about 5 months of camping in the desert in the winter time.

These are 130 watt panels. And his friend told me he isn't interested
in going commercial w/ this. But he did build one for this friend, but operated manually,
I missed getting a pic of it laying flat, but the panels looked to lay about 6 inches above the roof. If I was to criticize it (jealously will get me nowhere) I would be concerned about travel speeds.

It looks like maybe the 100W or 120W size panels...

He probably only gets around 10-12AMPS of usable power out of the two solar panels. Having the tracking just make it last longer than the usual 5-6 hours of suntime.

What can you do with just over 100WATTS of free power... You sure can't live off the panels alone. Best to store the power in batteries for future use. 100WATTS won't totally recharge your batteries especially if you are using them at the same time... 100WATTS is a great trickle charge however to keep the batteries topped off if they are already charged..

I'm just now getting interested in the solar panels but from what I already know about camping of the power grid and what it takes to keep the battery banks charged it seems if you go SOLAR you have to go BIG... You just can't get the high DC CURRENT you need with just a couple of panels to replace what the generator can get by running your on-board smart converter/charger.

I'm working to start out with two 120WATT panels on my off-road POPUP setup. It just makes good sense to tap into the free power from sun... This will add to my battery banks when I am not allowed to run my generators except during certain hours at a lot of places we go to here on the east side of the US. Got to help out but with my hugh battery drain running all of our toys in the one day/night run off the batteries I don't see how I can get away from having to run the 2KW generator at least three hours a day. The solar panels alone just can't keep up with we pull out of the batteries each day/night run.

My observations anyway... haha

Roy Ken

Wonder how many watts each panel is and brand?
Looks pretty neat. Thanks.
He should sell a "plan" on how he built it.