Something I do not understand...

[TaliaDPerkins]

Even derating used panels by 20% to be safe in estimating what power they can yield, it seems used panels can be had for about 1/3rd the price of new. I could put 10 of 400W panels nominally derated to 320W in a strip down the center of my 37' Thomas. That would be nominally 20+kWh collected on a sunny short winter day, with an installed collection wattage of 3200Wh an hour.


I do not understand why full timers are not maxing out their solar capability at these prices, I see 400W - 500W - 600W being referred to as usual and 800W - 1000W as being a lot.


How am I so far out of line thinking I should go with 3200W of panels? Yes I know I'll need more than 1 MPPT to handle that, and battery isolation to permit charging potentially unlike strings. I plan on two inverters so I redundantly have that capacity.

[Rwnielsen]

I think 2k of solar will work for me. I also like the idea of redundant mppt charge controllers. I'm building a 24 volt system, 8s2p, I believe. I have generators to back me up and somewhat limited roof area (3 AC units). I don't understand the thinking behind using 3 or 4 100w panels. The numbers just don't add up

[TaliaDPerkins]

..in fact, I just pulled the trigger on nominally 5.2kwH of panels from SanTan solar.


I aim to mount them on the sides of my bus in a tilt up installation where they should produce shaded areas reducing solar gain when cooling demand predominates.


Wood heat will be used when solar gain would otherwise be desired, as with winter heating. I have 8.6ac to cut firewood from...


...unless of course I merely decamp to a latitude where I do not care about heating...

[HamSkoolie]

We plan on 3-4 thousand watts on the roof, perhaps more, with the intent being that the entire roof be covered by solar panels, a center wood walkway, and wood over any areas not covered by panels or used by vents and hatch. The entire structure will be above the existing bus roof by several inches to provide a means of shielding the roof from solar heat as well as providing air flow between the roof and underside of the panels/decking in order to provide heat dissipation.
While this will provide more power than our batteries can hold on a bright sunny day, it will also allow use of both mini split AC's as well as other loads while still charging the batteries AND on those days with poor solar production, will do better than a minimal array in maintaining available battery power.