Solar panels

[camperguy99]

Don't think the ability of #6 to handle 200 amps is the issue. A small voltage drop between the converter and battery bank will dramatically change the batteries acceptance rate reducing the charge rate. Thus the time required to bring the battery up to full is greatly extended. You also have to make sure the both the positive lead and the ground lead are large wires as well. As little as 0.2V drop in both the pos and neg leads will limit the acceptance rate.

[Bandit]

True, the additional current results in a larger voltage drop and reduced peak charge current. The 75A initial charge rate is real as measured and a significant improvement over the 35A. This does not, however extend the overall charge time. It just changes the shape of the charge curve. As the current drops, so does the voltage drop resulting a higher current at a later point in the charge cycle. Its a sort of self-compensating result. If your metric was time to 80%, then it might be a little slower, but my goal is to be able to fully recharge the batteries during the day. So far it has met this goal. I have a Bluetooth current/voltage monitor and the Renogy solar charge controller has a Bluetooth monitor function. I can predict to the microsecond when my batteries will go dead,Ha Ha. I have dealt with these kind of issues for work for 25 years so i have some small experience in this area

[engrprof]

Originally Posted by m1noel

I added 3 more 100W panels. Total cost for panels and connections was well under $400 for DIY. My dealer wanted $1800. Took me about 45 minutes total. Made a big difference in how much we use the generator when dry camping. Usually only about 20 minutes in the morning when using the coffee pot and microwave.
Mike

How did you know where to mount the brackets for them? We have a 3901 also.

[m1noel]

Originally Posted by engrprof

How did you know where to mount the brackets for them? We have a 3901 also.

I went up on the roof and laid them out where I wanted them, then screwed them down with Dicor under the brackets, then over the screws as per the online instructions for the panels. Very solid.

[taylorbob1]

Search “drill less solar mounts” on the Thor Forum
Many are using that method now
I installed that way and it works great

[HaRVey]

Originally Posted by Long & Winding road

Well maybe your right....and im not expecting too much out of my system.

I dont want to overthink this either. I want to start kinda small (200 watts) and add one or two more panels as I go. Plus Im limited on room for batteries and roof space for pannels.

But dont they say "for every 100 amh battery you need 100 watts of solar" as a general rule? Of coarse they are refering the to "entire" battery knowing that your only need to charge for 50% of that.

AND most are figuring the full 5 hours of sunlight a day where you and me are being more realitic with 3 hours a day to be safe. If every day was sunny and you live in the southern states you should realize 5 hours a day (but around 3 in the winter).

So 100 watt solar x 5 hours = 500 watts and if you figure 50 amh of useable juice then you get back around 41.2 amps per a day with that setup (as a general rule). But in reality Im sure its less.

Im just going to start slow. I dont really need solar .... it just something I want to do.

This is really my test project for when I add solar to my house in 5 to 10 years. I like to be close to net zero at home by the time im ready to retire.

If this is a test project for home solar, there are a quite a few different things to consider if your goal is a "net zero" production-usage.
Many electricity providers limit the size of an system you can install based upon your last year's usage because they want to control/manage overall power distribution. We used more power than usual for the year before and wrote a letter accompaning our application our intend to convert water heater, dryer and stove to electric to justify the oversizing of our system, most of which we did. End result, a 17500kw system (annual production estimate for our 9.8kw array) with ~11000kw usage which has provided net zero since we installed it (last 3 years in SoCal). You will also need either an equally expensive battery bank (or generator) plus a transfer switch in order to use your solar if the grid goes down because they don't want you backfeeding the grid and electrocuting repairmen.
So, I would recommend a 1.5x factor of solar verses usage and size both solar and batteries based on how long you want to go without shore or generator... (which still won't help if the sun isnt shining)

[engrprof]

Originally Posted by m1noel

I went up on the roof and laid them out where I wanted them, then screwed them down with Dicor under the brackets, then over the screws as per the online instructions for the panels. Very solid.

So brackets can be mounted anywhere on the roof? Solar panels can be side-by-side, end-to-end? I thot any screws in the roof had to be placed on the beams? And how does one know where they are? What size/length screws did you use? Did brackets come with the panels or u make them? Do u have a pic of the completed project? Sorry for so many questions.

[HaRVey]

Yes the brackets can be anywhere (try to avoid areas where AC power runs) and the panels in any orientation. The screws just secure the brackets in place but the primary strength if from the Daycor adhesive. Don't use screws longer than needed (~1/2 -3/4). Do try to position panels to minimize shadowing from AC, Satelite, vents, etc. because shadows over one element of a panel can actually kill the whole panel and all panels in series with the one affected. For that reason I like to connect my panels in parallel groups of series wired pairs. (Talk to your panel and controller manufacturer about panel, wire and controller sizing and configuration to meet your needs)

[Long & Winding road]

Originally Posted by HaRVey

If this is a test project for home solar, there are a quite a few different things to consider if your goal is a "net zero" production-usage.
Many electricity providers limit the size of an system you can install based upon your last year's usage because they want to control/manage overall power distribution. We used more power than usual for the year before and wrote a letter accompaning our application our intend to convert water heater, dryer and stove to electric to justify the oversizing of our system, most of which we did. End result, a 17500kw system (annual production estimate for our 9.8kw array) with ~11000kw usage which has provided net zero since we installed it (last 3 years in SoCal). You will also need either an equally expensive battery bank (or generator) plus a transfer switch in order to use your solar if the grid goes down because they don't want you backfeeding the grid and electrocuting repairmen.
So, I would recommend a 1.5x factor of solar verses usage and size both solar and batteries based on how long you want to go without shore or generator... (which still won't help if the sun isnt shining)

Yep, thanks. I would shoot for net zero but still be tied to the grid. I think I would also have a battery bank large enough for two days incase power goes out.

Once Im ready (could be 5+ years from now) I woud contact my power company to see what I need to do in order to connect to the grid. But I plan on installing my own solar panels and battery bank/inverter (Maybe a Tesla power wall?) but Im might need to hire someone for the grid connection to be safe.

One step at a time for me and im in no rush.... just a long term goal before I retire.

[taylorbob1]

Originally Posted by Long & Winding road

Yep, thanks. I would shoot for net zero but still be tied to the grid. I think I would also have a battery bank large enough for two days incase power goes out.

Once Im ready (could be 5+ years from now) I woud contact my power company to see what I need to do in order to connect to the grid. But I plan on installing my own solar panels and battery bank/inverter (Maybe a Tesla power wall?) but Im might need to hire someone for the grid connection to be safe.

One step at a time for me and im in no rush.... just a long term goal before I retire.

The best time to put in a Home Solar System...
Yesterday

In CA, the Utilities charge 30+ cents per KW hour, and 40+cents during peak hours
One cannot afford not to have solar

[Bob Denman]

We're at about 11 cents per KW hour...
The Monthly electric bill for our house is less than fifty bucks.

[Long & Winding road]

Yeah ours is not to bad here in AR. Like $75 - $100 for 6 mo of the year then like $175 - $225 for the hot months. But we try to be effecent.... If I had free power (or money) to burn I would use more.

[taylorbob1]

For both of you it makes no sense to install a home solar system
At $1,000 per panel installed ($250/panel cost), it makes sense in CA because the cost of electric is so high and we get a lot of sunshine.
But many other locations it’s not cost effective

[Long & Winding road]

Im sure your right.... But im thinking by the time I retire (10 - 15 years from now) the prices will be up and I rather pay out of pocket BEFORE I retire then reep the rewards for free power (for the most part).

Yeah... dont make much sense .... thats why I would only do it myself (save the labor cost which is close to half the price?) and have something to tinker with when im old.

Plus who knows what will happen with untility companies and all of the electic cars on the roads by then. Electicity demand will only go up as time goes on .... and if the is supply is low.... well you know what happens to prices.

But right now it dont make any sense at all for me.