Are these solar panels any good?

[funmoneypit]

All you solar panel experts, are these panels any good?

Evergreen ES-E-220-fc3 (220W) Solar Panel

I am researching and trying to learn as much as I can but it is a lot to take in. My coach is pre-wired for solar and has a controller already. It isn't at my house so I have to wait to verify the manufacturer and specs on it.

I found a guy selling these 220w panels brand new for $137.50. He says they are NOS so I am concerned about old technology, etc.

Any help is greatly appreciated for this newbie! Thanks!

[leroybrown]

If you give me new solar panels and paid for the install, I wouldn’t put them on our rig. Not worth the trouble and don’t want that junk on my roof. If the batteries get low the generator starts itself and runs for a hour. Even works in the dark lol! And with our total electric rig it’s not even feasible or pactical. And most of the time we’re running the AC so generator is a must and it also keeps the batteries charged.

[twinboat]

Originally Posted by leroybrown

If you give me new solar panels and paid for the install, I wouldn’t put them on our rig. Not worth the trouble and don’t want that junk on my roof. If the batteries get low the generator starts itself and runs for a hour. Even works in the dark lol! And with our total electric rig it’s not even feasible or pactical. And most of the time we’re running the AC so generator is a must and it also keeps the batteries charged.

Not sure that's the kind of info the OP was inquiring about. In thinking you don't have much to contribute to " Going Green "

[leroybrown]

And furthermore I would never buy a used rig with solar panels on the roof. Too many holes and places for leaks and such. And too many hack wiring and installation jobs by people who think they need solar power!

[twinboat]

They look like 24 volt panels so you will need to use a MPPT type controller.

A standard PWM controller will clip the output in half with 24 volt panels. They only allow 14 volts thru.

A MPPT controller converts the higher voltage to higher amps.

Example: 24+ volts at 5 amps sent in to the controller will suppy 14 volts at 8 to 10 amps to the batteries.

You really need to know what controller you have before buying the panels. It still may be worth it at that price, with replacing the controller.

The gauge of the installed wiring is another factor, depending on how many panels and whether you wire in series or parallel.

[funmoneypit]

Originally Posted by leroybrown

If you give me new solar panels and paid for the install, I wouldn’t put them on our rig. Not worth the trouble and don’t want that junk on my roof. If the batteries get low the generator starts itself and runs for a hour. Even works in the dark lol! And with our total electric rig it’s not even feasible or pactical. And most of the time we’re running the AC so generator is a must and it also keeps the batteries charged.

So I guess this question wasn't for you. Not sure why you are in this forum then but whatever.

Originally Posted by twinboat

Not sure that's the kind of info the OP was inquiring about. In thinking you don't have much to contribute to " Going Green "

Exactly! Thanks twinboat.

Anyone have any knowledge to share on these panels? And to think I got excited when I saw 3 replies.

[funmoneypit]

Originally Posted by twinboat

They look like 24 volt panels so you will need to use a MPPT type controller.

A standard PWM controller will clip the output in half with 24 volt panels. They only allow 14 volts thru.

A MPPT controller converts the higher voltage to higher amps.

Example: 24+ volts at 5 amps sent in to the controller will suppy 14 volts at 8 to 10 amps to the batteries.

You really need to know what controller you have before buying the panels. It still may be worth it at that price, with replacing the controller.

The gauge of the installed wiring is another factor, depending on how many panels and whether you wire in series or parallel.

Thanks again twinboat. I will be at the rig Thursday so I will be able to check out the controller then. I won't pull the trigger on the panels until I verify the controller. With it being factory installed, I am betting it is pretty much the cheapest one they could put in. I was thinking two panels.

[Searching_Ut]

They would have to be pretty old for there to be any tech difference that would be of concern in my opinion. It would only be of concern to me if I was considering possibly increasing the size of my future and wanted to be able to use matching panels in the upgrade.

Looking at the posted data it appears they have the 80 and 90 percent output warranty data reversed. Otherwise they looked to be pretty standard. It’s hard to say on any panel how it will do over time as they are constantly changing. From what I’ve seen though if you don’t have issues right away you probably won’t.

[harryn]

The only real challenge with large panels is - they are a bit large to hoist up on top of the RV, and a bit big so you should fasten them down more locations than a more typical RV size panel. (about 1/2 of the size of those)

[hclarkx]

Originally Posted by funmoneypit

Any help is greatly appreciated for this newbie! Thanks!

I don't see anything wrong with these panels if they will work with your MPPT solar controller. If they will, I would compare them with the Renogy 100W panels in terms of panel area required, ease of installation (weight and bracketry), how well they fit the open space on top of your RV (room for expansion), etc.

Brackets ready made for the Renogy panels and work well. They might work with these panels or if not there are others.

For sure I would not do anything that will preclude or make expanding your solar difficult. You will love having solar for a lot of reasons not the least of which is that your lead-acid batteries will last a lot longer because you can top them off more easily and more often with solar and doing that often is essential for long battery life.

I started with 200W (2 100W panels) then went to 400W and now have 600W. When I went from 400W to 600W I needed more MPPT controller capacity and got a second 30A one rather than replace the earlier one with a larger one. This was ideal for reliability (gave me two independent solar systems) and optimum panel performance since the RV roof is crowned and three panels run down one side and three down the other side. Each group of three has it's own controller.

So, I wouldn't skimp. Do it right. You'll love it.

[CountryFit]

Originally Posted by funmoneypit

All you solar panel experts, are these panels any good?

Evergreen ES-E-220-fc3 (220W) Solar Panel

I am researching and trying to learn as much as I can but it is a lot to take in. My coach is pre-wired for solar and has a controller already. It isn't at my house so I have to wait to verify the manufacturer and specs on it.

I found a guy selling these 220w panels brand new for $137.50. He says they are NOS so I am concerned about old technology, etc.

Any help is greatly appreciated for this newbie! Thanks!

The price appears to be decent.

I looked up the panel spec, it says "Peak Efficiency 13.43%", that is lower than most of the other good ones typically around 16% in today's market.

My panels are Sunpower, 20% efficiency. Considering the limited size on rooftop, I would go with a higher efficiency panel if i were in the position to do it.

Just a reference point for all whoever are reading this post.

[hclarkx]

Originally Posted by CountryFit

The price appears to be decent.

I looked up the panel spec, it says "Peak Efficiency 13.43%", that is lower than most of the other good ones typically around 16% in today's market.

My panels are Sunpower, 20% efficiency. Considering the limited size on rooftop, I would go with a higher efficiency panel if i were in the position to do it.

Just a reference point for all whoever are reading this post.

Definitely 13.4% takes about 50% more panel area than 20% panels. But if there's room on the roof and weight is not an issue and is, I'd give them a look. Being older panels would be a concern mostly if they are used and maybe are no longer providing their rated output (under rated conditions).
The newer better panels like the 20% Sunpower typically last longer (power drops off more slowly). But, that's probably not an issue on an RV where the RV itself may die before the panels do.

[funmoneypit]

Well I got the MH back home today and checked out the solar controller. Like I thought, it is about the cheapest they could get. It's a PWM and only 10 amps so only one 100w panel. If I am going to put up panels, I am going to do more than 100w. Now I will have to see what wires they ran. I can't believe they are very big with a 10a system. I would upgrade the controller so I could at least use two of the 220w panels. I have plenty of space on my roof so that won't be a problem.

Thanks for all the replies!

[hclarkx]

Originally Posted by funmoneypit

Well I got the MH back home today and checked out the solar controller. Like I thought, it is about the cheapest they could get. It's a PWM and only 10 amps so only one 100w panel. If I am going to put up panels, I am going to do more than 100w. Now I will have to see what wires they ran. I can't believe they are very big with a 10a system. I would upgrade the controller so I could at least use two of the 220w panels. I have plenty of space on my roof so that won't be a problem.

Thanks for all the replies!

Don't get too carried away with conductor size. One often sees recommendations for conductors heavier than needed.

#10 is 1.018 ohms/1000'
#12 is 1.62 ohms/1000'
#14 is 2.58 ohms/1000'

220W panel ... current is about 11.6 amps at max output. Voltage is about 30 x 2. From I squared R the loss in 60' of wire is:


#10 ......... 11.6 x 11.6 x 1.018/60 = 2.4 Watts (0.6W at half power)

#12 ......... 11.6 x 11.6 x 1.62/60 = 3.6 Watts (0.9W at half power)

#14 ......... 11.6 x 11.6 x 2.58/60 = 5.8 Watts (1.45W at half power)

These losses are at full power (440W). You get full power only for a few minutes even on a perfectly clear day -- very rare). At half power these losses are lower by 75% as noted. Under all but perfect sun, they are inconsequential. If the factory wiring is #14 or larger, you are good to go with MPPT. You can't go below #14 ... it's thermally good for around 15 amps depending on insulation temperature rating.

My point is that if you are going MPPT with panels in series, pass on the #6 and #8 that people often recommend.

IMHO PWM isn't an option but if you put panels in parallel on a PWM controller, you will want heavier wire. At least #10 for the two 220W panels.

BTW, you might be able to put two 100W panels in parallel on the factory PWM controller. They deliver only about 5 amps each (at about 19V). If you can't find specs on the factory PWM controller that tell you 200W is okay, it's probably better put on ebay. Some PWM controllers are not three-stage. Most MPPT controllers are. You really want three-stage (bulk, absorption, float) for optimum charging and long lead-acid battery life.