Solar Panel resizing?

[Phantom]

More is always better but I'm quite limited due to space on the roof due to my solar panel, sat dome, TV aerial, skylights, etc. I currently just have a single 120w panel but would like to enable more power usage during the day. I could maybe fit two additional 60 watt panels or smaller either side of a skylight or even fit a larger one in place of the current one? Another thought is to fit a large flexible one onto the front roof curve? I'm just thinking aloud but would appreciate any thoughts?

 

[Deleted member 5042]

I think the general consensus is flexible ones fail sooner and give less output because of their inability to dissipate heat as effectively as a rigid. With the central positioning of skylights found on motorhomes I found this to be the largest practical panel because of its narrowness at 180w

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Can your controller cope with a bigger array?

 

[St3v3]

I have a panel over a skylight. It still opens to give ventilation, and you actually get more light than you'd think. I got the idea from Phil, he's done the same.

 

[QFour]

I have been looking at the same problem after running the batteries low and not enough output from the 150w panel. Could put extra on the roof but it needs to be pointing at the sun for the best performance. Watched one guy up a ladder on an Aire propping his panel up. I have been thinking about a separate one that you get out when needed and put in the most advantageous position ie pointing at the sun. It increases the power output considerably as does cleaning them. I have one on the side of the shed at home pointing south. During the winter months it’s not far off vertical.

 

[maingate]

I have been looking at the same problem after running the batteries low and not enough output from the 150w panel. Could put extra on the roof but it needs to be pointing at the sun for the best performance. Watched one guy up a ladder on an Aire propping his panel up. I have been thinking about a separate one that you get out when needed and put in the most advantageous position ie pointing at the sun. It increases the power output considerably as does cleaning them. I have one on the side of the shed at home pointing south. During the winter months it’s not far off vertical.

That's what I have. A 100 watt panel on roof and a 90 watt freestanding panel that plugs into the system via a junction box in a locker. It works well.

 

[Patnlorewatson]

More is always better but I'm quite limited due to space on the roof due to my solar panel, sat dome, TV aerial, skylights, etc. I currently just have a single 120w panel but would like to enable more power usage during the day. I could maybe fit two additional 60 watt panels or smaller either side of a skylight or even fit a larger one in place of the current one? Another thought is to fit a large flexible one onto the front roof curve? I'm just thinking aloud but would appreciate any thoughts?

I have read if you fit a good MPPT controller you should get 30% extra draw from your panel. I think it's worth checking out.

 

[Phantom]

I have a panel over a skylight. It still opens to give ventilation, and you actually get more light than you'd think. I got the idea from Phil, he's done the same.

Of course, that would be the answer! The skylight over the bed has little function really.

 

[Trotter]

Adjusting the angle of a panel. Great idea in principle, I agree.
I was thinking of doing the same. But, I’m an idle so’n’so. Unless I spend a fortune on an electric lift, after the second or third climb onto the roof, it won’t be done again. Then of course, there’s the first time I drive away with it raised.
No, kiss* is the way for me to go.
I’m fitting a second 100w panel, thanks Chris, to run in parallel or series ( whatever, the +’s together and the -‘s together, to give 200w @ 12volt) , don’t really care what it’s called, as long as it works lol.
I’ll have to remove the old mounting feet, not sure if I’m going to cut them down and fill the cavity with Sikaflex,or use the method a new forum member ( Gadget John) showed on a recent video. String, WD40, and loads of time. Depends on the weather and if I’m comfortable sitting on the roof. Might need to take my Brave pills.

* keeping it simple, stupid.

 

[SquirrellCook]

Now that mine has been taken home I can see I've shaded a panel, explains why it charges better in some directions. For future builds/refitting panels I will try and mount the down the length of the roof. Each side being connected in series, then if one side is shaded the other side will do well.

 

[Okta]

Now that mine has been taken home I can see I've shaded a panel, explains why it charges better in some directions. For future builds/refitting panels I will try and mount the down the length of the roof. Each side being connected in series, then if one side is shaded the other side will do well.

I thought it was the other way round, in series the resistance in the shaded panel impedes the flow of both panels. In parallel they operate independently. Could be wrong but when I had 2 portable panels that is what seemed to happen.

 

[SquirrellCook]

I thought it was the other way round, in series the resistance in the shaded panel impedes the flow of both panels. In parallel they operate independently. Could be wrong but when I had 2 portable panels that is what seemed to happen.

Yes you are correct, hence the panels connected in series down one side. The other side has panels connected in series, both of these are then connected in parallel. So if your roof furniture is casting shadows it will only be on one side. I expect even an aerial could be naughty too. On both our coach conversion the roof is curved.

 

[wildebus]

Of course, that would be the answer! The skylight over the bed has little function really.

Panel over that would also double as a sound deflector from rain hitting the roof