Lazy Daze Owners' Group

Lazy Daze Forums => Lazy Daze Renovations & Improvements => Topic started by: Marciebp on December 12, 2016, 09:41:59 pm

Title: Solar Panel
Post by: Marciebp on December 12, 2016, 09:41:59 pm
A friend has a solar panel for me, if I would like it.  It just sounds enormous and maybe over kill.  Any thoughts?  It's 340 watts and 78.5 x 39.4.  We have a RK.
Title: Re: Solar Panel
Post by: Larry W on December 13, 2016, 02:21:55 am
A friend has a solar panel for me, if I would like it.  It just sounds enormous and maybe over kill.  Any thoughts?  It's 340 watts and 78.5 x 39.4.  We have a RK.
Well, the answer is for someone to get up on the roof, with a tape measure, and see if the space is available.
Every LD's roof is a little different. RKs are somewhat rare.

Larry
Title: Re: Solar Panel
Post by: Kent Heckethorn on December 13, 2016, 02:36:50 am

"...A friend has a solar panel for me, if I would like it.  It just sounds enormous and maybe over kill..."


Marcie,

Solar panel overkill on a Lazy Daze? Is there such a thing?

You be the judge...

https://youtu.be/SJaSWG4juF8

https://youtu.be/fw1ISW6geqY

Think she's trying to operate a particle accelerator?

Just sayin!

Kent
Title: Re: Solar Panel
Post by: Marciebp on December 13, 2016, 03:12:48 am
Now that's hilarious
Title: Re: Solar Panel
Post by: Kent Heckethorn on December 13, 2016, 03:19:30 am
She seems pleased, though. Very creative.

I just wonder how the panels enjoy freeway speeds.

Kent
Title: Re: Solar Panel
Post by: Steve on December 13, 2016, 10:04:32 am
A friend has a solar panel for me, if I would like it.  It just sounds enormous and maybe over kill.  Any thoughts?  It's 340 watts and 78.5 x 39.4.  We have a RK.

It is likely a commercial panel, and will require a top-notch solar controller rated for the voltage and power.  In general, more smaller panels are better for performance (and roof-fit) in conditions other than open desert, to avoid shading issues.

Steve
Title: Re: Solar Panel
Post by: Joan on December 13, 2016, 10:32:00 am
"It is likely a commercial panel, and will require a top-notch solar controller rated for the voltage and power."
----
Matching a solar charge controller, a multi-stage converter, and the appropriate battery set-up to this 340V panel were my first thoughts when I read the initial post.

A solar "system" is not just a panel or panels; even if there's space for the panel, a well-functioning system requires components that work together efficiently and the set-up needs to be planned out, matched, and wired together by someone who knows what he or she is doing. "Free" often isn't.

As ever, YMMV.

Joan

Title: Re: Solar Panel
Post by: Eric Greenwell on December 15, 2016, 07:24:28 pm
What's the panel voltage? If it's, say, 60 volts, the wiring to the regulator near the battery only has to handle 6 amps, easy to to do with 12 AWG wire. For that voltage panel, I'd suggest a MPPT charge regulator with a 70+ volt rating - very available. I think the biggest issue is mounting it.
Title: Re: Solar Panel
Post by: Marciebp on December 20, 2016, 01:12:20 am
Eric,
The panel - 43 volts. 
Title: Re: Solar Panel
Post by: Larry W on December 20, 2016, 03:00:10 am
Eric,
The panel - 43 volts.

Victron makes  a controller that will work.
https://www.victronenergy.com/upload/documents/Datasheet-BlueSolar-charge-controller-MPPT-100-30-&-100-50-EN.pdf
Victron BlueSolar Charge Controller MPPT 100/30 - 30A at 12/24 Volts (http://baymarinesupply.com/store/victron-blue-solar-mppt-charge-controller-100v-30amps.html)

The downside of having a panel with an odd voltage is if you ever want to add more panels, it will need to have the same voltage output, for best efficiency.

Panels are cheap today, compared to the prices of just a few years ago.
You might be better served buying panels that properly sized for the roof's real estate and of a more common output voltage.

Larry
Title: Re: Solar Panel
Post by: RonB on December 20, 2016, 03:28:09 am
Hi Larry. That sure is a nice controller. Shows how much MPPT controllers have improved. I bought mine in 1999 when most people had never heard of one. Mine was made by a company in Encinitas and cost more than this one. I don't think Marcie would need to add any more panels than just this one panel.
  I've only got about 130 watts, but I don't have the weight capacity for more batteries. RonB
Title: Re: Solar Panel
Post by: Eric Greenwell on December 21, 2016, 09:17:56 am

The downside of having a panel with an odd voltage is if you ever want to add more panels, it will need to have the same voltage output, for best efficiency.


340 watts might be enough, eh?    ;D

And since it's free, only the labor of installing it is lost if he decides he needs to replace it with more panels, as the controller would still do the job.
Title: Re: Solar Panel
Post by: Larry W on December 21, 2016, 12:28:28 pm
340 watts might be enough, eh?    ;D

And since it's free, only the labor of installing it is lost if he decides he needs to replace it with more panels, as the controller would still do the job.

For many, no. Fulling timing in the winter can require much more solar, if you are a heavy user.
I was just pointing out this disadvantage. It hasn't been established if the panel will even fit the roof.

Larry
Title: Re: Solar Panel
Post by: Marciebp on December 21, 2016, 02:18:21 pm
Sorry Larry, I meant to establish that it does fit. The panel goes to the edge on the 40.4 side. 
Title: Re: Solar Panel
Post by: Larry W on December 21, 2016, 04:58:32 pm
I meant to establish that it does fit. The panel goes to the edge on the 40.4 side.
Panels mounted close to the edge of the roof are vulnerable to tree branches.
A panel can be ripped off if a branch gets under the panel, while the rig is moving, such as in an overgrown campground.
Consider armoring the exposed side and leading edge as shown here,
IM007142 (Small) | lw5315us | Flickr (https://www.flickr.com/photos/lwade/1415589055/in/album-72157602104742393/)

Panels need air space under them, for cooling. The hotter the panel, the lower the output efficiency.

Larry