Solar panel

Adding to KD4ULP - Larger panels cost less in terms of cost per watt, less roof space per watt and less installation cost. For my installation in 2014 a 12V panel system with PWM was only $100 less than a 24V panel system with MPPT. So 24V panels were a no brainer for me.

Start with an energy audit in watt-hours. Divide that number by five. That will give a good guideline to how many watts of panels would work well.

I like Renogy panels and MTTP controllers.
About $1 per watt.

Solar panels are not all imported from China although China does make a lot of them. My favorite brands non-Chinese brands are REC, Mission.
Solar panels are mostly a commodity and looked at on a watts per dollar basis. The best price on is typically a 60 cell panel which will be about 40" wide and 66" long. These will put out 30 - 35 volts and are what some people refer to as a "24 volt" panel. These are used by the thousands on homes and businesses and thus usually lower cost on a dollar per watt basis than smaller "12v panels". Yes, you will need an MPPT charge controller. In the residential solar business is pretty much unheard of to install any charge controller that is not MPPT. I think most of the PWM controllers are likely bought by RVers. Nothing wrong with that, it's just that PWM is far from the "standard" used in the overall industry.
Put as many and as large of panels on your RV that you can fit. Solar panels are relatively inexpensive compared to batteries, inverters, and charge controllers. Careful shopping should get you solar panels at around 50 cents a watt. If you pay more than $1 a watt it's an incredible rip off.

IMO the first thing is whether there is any room on the roof for the size of panel you are looking to buy. Cardboard simulations to check for that.

Worst is the air conditioner's shadow. But spacing of all those little tank vents, radio and TV antennae, and the bigger air vents can be critical. (Although you can panel over top of some of those with higher "legs" for the panels)

Panels are only one of the components of a solar system...panels, controller, batteries and wire. Before you buy anything do an energy use survey. What you use or what you want to use.

Another advantage with an MPPT controller is a higher harvest of amps from the panels vs a PWM controller.

time2roll wrote:
I recommend larger 24 volt home panels in series. Find some local surplus as shipping is expensive for these oversize items.
Shop by price per watt as these are just a commodity and will perform fine and out last the RV.

Those 24V panels WILL need a MPPT type of solar charge controller, more expensive than non-MPPT.

The only "advantage" to 24V panels and MPPT controller is you can use light ga wire from panels to controller..

You can also run "12V" panels in series but in reality not really much advantage..

I recommend larger 24 volt home panels in series. Find some local surplus as shipping is expensive for these oversize items.
Shop by price per watt as these are just a commodity and will perform fine and out last the RV.

How many watts you need? How many batteries do you have? Do you have an inverter?