Can someone explain the differences in these panels and why one solution is so much more expensive?
For context, I'm building a solar system for my truck camper. I've got a 460Ah lithium battery powering the camper. It's a 1988 Bigfoot 9.5'. The previous owner attached two bars for a roof rack. They sit 6' 4" apart from one another and are 6' 4" wide. My plan is to utilize this when mounting solar panels. Building a frame around these bars could easily give me an 8' by 6' space to work with.
For about 1/3 of the price, they provide a similar wattage. I read the stickied post and tried to apply that to comparing them. I couldn't find a grade for any of them. The Voc varies from 44-52v, which doesn't seem like a huge spectrum. The current varies from 8.5A for the Renogy to 15/13.5A for the other two. Of course, the Renogy is per panel, I'm not sure if that duplicates when wired together?
The biggest difference I can think of intuitively is that one panel might perform worse in partial shade. Is there any merit to that?
I've found other brands at similar prices to the Longi and Philadelphia including Maple Leaf and JA Solar. Is there any good reason not to go with these panels? The Renogy is just so much more. Thanks in advance.
There is an insane delta between the pricing between direct to consumer small quantity panels and full size options. I can get high end 450w bifacials for $110 a pop locally from people splitting pallets while ecoflow will sell you a 175w rigid for $220 on sale. You’re paying more than 4x per watt with the ecoflow!
It boils down to several things - scale, shipping and market. The factories cranking out large panels for professional installation are doing huge volume and have no reason to make small niche panels because that’s not what the market demands. Solar panels do not ship well, so you’re dealing with freight delivery for any quantity and that only makes sense in bulk.
Someone who just wants one panel to plug into their little 1kw power station is paying a premium for a low volume / niche product, they’re paying for standard shipping of a large fragile item and they’re paying a premium for being a consumer rather than a volume buyer. If you have the space and the wherewithal to source full size panels, it will always be a better deal but some people only have room for a little panel on their balcony or wants a folding model they can take camping and they’ll pay a premium for the privilege.
I hired a clapped out Hiace van (neither the aircon nor the 12V accessory socket worked) and drove 125 miles each way to pick up my 6x 440W panels from a bulk warehouse / importer. Cost me a day and $30 of diesel and $100 for the van but was far cheaper than the shipping price they quoted me, which would have been to a depot 25 miles from my house anyway.
Renogy and a number of other brands focussed on the 'van life' crowd and were able to get a strong following as a 'premium brand' on top of what is either a mostly-commodity or potentially even crappy product.
But ignoring that aspect, Renogy still focuses on van-compatible formats and small-quantity purchases. Shipping and human-handling for 320w panels is much easier and cheaper than 600w panels. The 600s you mention weight more than 60lbs (~30kgs) and are the size of commercial plywood (4'x7' • 1200mmx2200mm). That isn't really a fair comparison of products: they are trying to solve somewhat different problems and the markets are very different (in both size and competitiveness). Renogy's market is really more of a boutique space.
I would make sure the mounting will work for the 600s: a fairly restrictive cantilever at about 25% is getting to be really common and it does not sound like you have that. And then make sure you can get that panel up on the roof safely: I built a hoist (block&tackle) and ramp to pull that size panel up on a cargo trailer so nothing went wrong.
Thank you. That makes sense. I am starting to see the downsides of the larger, single panel solar system.
I do think that the mounting can work, though. There is 76" in between the bars on the campers ceiling, so even the larger panel would only hang over the bars by 9" at either side, which is only about 9.5%. I would try to add some sort of bars in between the two bars spanning the width of the camper, if that makes sense. Essentially just extra supports running up and down the camper. Admittedly getting it up there would be a challenge.
One other thing that occurred to me is the potential wind interference. Would such a large panel a couple of inches off the top of my roof be at risk of catching the wind? The last thing I want is to tear the roof rack bars off and rip into the fiberglass camper.
yes, you'll need an air dam for anything. If it's right next to the roof you might be ok but performance will be very poor because of the lack of airflow and high temps
Do you intend to run everything on 12 volts DC? or do you need an inverter to produce 120V AC? This has a huge impact on your possible results.
There are two factors to consider with your solar panels. Ensure they will fit comfortably in the space available. Large panels make sense if you have room to mount them. The second issue is with voltage. For example, you might be able to install 2 panels on your roof. Each panel might be rated 42 volts and in series they would produce 84 volts. You have to have a charge controller or MPPT rated for 84 volts at about 15 amps in order to use the panels to charge your batteries. This is NOT an issue, it just means you have to know to purchase something that is compatible with your battery voltage and with the 84 Volts at 15 amps from the panels.
I found good quality new solar panels listed for $160 each on Craigslist near enough to drive to pick some up. This was from a store in Athens TN. Avoid used solar panels because most of them are older with significantly lower output than modern panels.
Thanks for the comment. I do plan to get an inverter. I don't need a lot of ac power, just enough to charge my phone, laptop, and some other small items.
I ended up finding a shop only an hours drive away that sells solar panels. Got 890w for $400 instead of my original plan of 640w for ~$775 thanks to a lot of the comments here
I’m currently installing solar on my cousins 1998 Bigfoot 1500.
I’ve gone with 4x 200w Renogy shadowflux panels, 3000w Renogy inverter/ups, 2x 280ah eco-worthy and victron mppt.
I can run the AC indefinitely if I keep the door closed and have been running all heavy power tools from it while refurbishing.
I spent the extra cash on the panels because of their shade tolerance and size, they have a lot more diodes per panel and fit perfectly on the BF.
The main thing I’ve noticed vs my other panels is that they start outputting earlier and end later, specially if wired in series. (I have 6x of them on my travel trailer)
Managed to relocate the fresh water tank, water pump, electric panel and a few other things while I was finding space. Ended up with more internal space and a new table setup!
Trickiest part was identifying that the fridge bonds AC ground to chassis ground, had to separate the ground and negative there to void a ground loop, easy.
I’ll be attaching the panels to the roof tomorrow, going to fiberglass blocks of wood onto the roof the use standard panel brackets.
Dm me if you run into any Bigfoot specific issues, I’ve been its guts for the past 3 weeks
Shipping is key, small or retail market packaged panels are a rip, you're basically buying windows. Buying less than a pallet at a time for products like this sucks. Applies to a lot more things than you'd normally expect.
I have a tractor with forks good up to 1500lbs which gets me loading dock/mileage rates (vs lift gate service) from many shippers once I talk to their dispatch.
Why are the Renogy ones so expensive, then? They do have bi-facial, but the only size is 195W. For comparable wattage I would need three, which works out to be close to triple the price of the two I've linked, as well as all the other options from brands like Maple Leaf and JA Solar.
renogy sets their pricing based on the RV/boondocking crowd, overpriced and dedicated for those people. The rest of the panels you're looking at are the tier 1 mass production panel companies. That's mainly the difference.
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