Solar panels. Looking to buy several.

Panels are basically a commodity so you are shopping by price and size. The physical size must fit the open space on the roof without much shade from the other vents, antenna, or air conditioner. Even a small shadow on one cell can reduce the entire panel output 30% to 80% or more.

You also need a controller. If you get 12v panels and connect in parallel then a low cost PWM controller is fine. For 24v panels or anything wired in series you will need an MPPT controller to correct the voltage.

Ratings and specs need to match the equipment. Otherwise it is plug and play.

Don’t buy 12 volt panels. Put residential panels on the roof and use an MPPT controller. Much cheaper and better. The 12V are so expensive for what you get.

Hi Rusty,

This series of articles may be a good place to start:

https://freecampsites.net/adding-solar/

RustyMacIntosh wrote:
Since frequently we are out in the boonies with either the coach or the travel trailer, rather than to run the generator to recharge the house batteries, I've seen folks with solar panels.

So....what is the skinny on the unwashed purchasing several panels.

Yesterday I saw 100w panels at Harbor Freight. I've seen German panels being sold on Ebay and Amazon.

Are panels plug and play? Do we just prop the panel up towards Mr. Sun, run a power line to the batteries?

Is there more to it than this?

In regards to a purchase of panels, surely there must be panels that are good, bad and ugly. Which panel would be the best purchase for the $$$?

I use a rule of thumb that panels should cost no more than $1.00 PER WATT. HF panels don't qualify INHO.

There is indeed a lot more to it than meets the eye. When I started looking into it,I came upon a book that led me to a web site that has been a fabulous resource. Surf over to mobile-solarpower.com and find the answers. The author thereof is very good at explaining things so that even us dummies can understand and even has designed several sizes of systems with suggested parts and places to buy them. What’s more, he updates them frequently to account for varying market and state of the art conditions.

I have used his 400 watt system as the basis of my own build for my TT. It was easy to do and has proven perfect for my needs. It replaced a now deceased small generator.

Btw, the panels at Harbor Freight are not recommended. They will likely be useful for only 5-10 years, being amorphous, whereas polycrystalline or monocrystalline panels should last for at least 25-30 years. They are also not as low cost. I just bought 4-100 watt polycrystalline panels from Home Depot for $75 each and they have 25 year guarantees.

Your questions can be answered best with some reading. Try WindyNation’s website. Yes, a sufficient solar system eliminates need for a generator most days when AC isn’t needed.

A balanced solar system requires the right combination of panels, wire, controller and batteries. If one is “wrong” the system won’t work well.

You'll want to feed the batteries through a controller to keep the voltage withing acceptable limits for charging batteries. Unregulated solar panels will over charge the batteries and possibly fry your fridge circuit board.

If you get a portable kit, they usually come with a controller and all the cables needed to connect to the batteries. GoPower has several sizes to choose from, but they are a little pricey. However, if you're not going to mount the panels on the roof, this may be your best option.

More important than how much solar is how much battery. If you have 2 group 24 12v RV/marine "deep cycle" batteries, all the solar in the world won't get you through the night with the furnace running.

The general rule of thumb is 100 watts of solar for every 100 amp hours of battery. Mounting the panels on the roof and running wires to the controller and then to the batteries is a medium skill task. Panel brackets are screwed into the roof and require proper sealing.

I'd stay away from the cheap panels. Substandard wiring and construction makes them prone to catching fire.