Downside to using residential solar panels (on top of a RTT)

M

monkeyodeath

Member
Hoping to add some solar to my Bundutop setup.

The Bundutop is a hard-shell rooftop tent with a totally flat aluminum roof with about 75" x 45" of space, and a ~50lb weight limit.

Initially I figured I'd just get a pair of 100w Renology panels and call it a day. Mainly looking for something that can support a fridge on desert trips.

But I'm wondering if I should also be looking into residential panels, which do appear to be a bit cheaper for their output -- given that I've got a fairly wide-open space for install.

I don't mind fabbing up some mounts.

Residential panels seem a bit more difficult to shop for. For example, here's a guy selling used 230-watt panels for $100. https://losangeles.craigslist.org/ant/for/d/palmdale-sunpower-solar-panels/6988467773.html

Is this even a smart option? Should I only be looking at new residential panels? (Which are kind of difficult to shop for retail...)

Mainly trying to figure out if the price difference is worth it, or if it's so much extra hassle and research to use these.
 
plh

plh

Explorer
I'm doing this route. Bought a used 365 watt panel. Just need to make sure your charge controller can handle the typical higher voltage from the residential/commercial type panel.
 
luthj

luthj

Engineer In Residence
Most are higher voltage, so they need an mppt controller. Otherwise there isn't any downside. You can find these kinds of panels as surplus from local residential installers at decent prices sometimes. Shipping is usually expensive on a single panel.
 
teotwaki

teotwaki

Excelsior!
For a 12v battery system the working voltages of the residential panels will require a MPPT controller
that can handle the max voltage and wattage the panel could deliver. The savings on the panel
might be negated if you need a fairly expensive controller

Amazon.com : Victron Energy SmartSolar MPPT 100V 20 amp 12/24/48-Volt Solar Charge Controller (Bluetooth) : Garden & Outdoor

Amazon.com : Victron Energy SmartSolar MPPT 100V 20 amp 12/24/48-Volt Solar Charge Controller (Bluetooth) : Garden & Outdoor
www.amazon.com

00303_6WQ11rVHjyv_600x450.jpg
 
J

jonyjoe101

Adventurer
You will appreciate the more power and simpler installation of one large panel. My 240 watt panel with the ecoworthy 20 amp mppt (100 dollars) put out about 12 amps mounted flat on my roof when the sun is overhead. That will easily keep up with your fridge.
 
1leglance

1leglance

2007 Expedition Trophy Champion, Overland Certifie
I have been running a big home panel I got new for $150 from solar-electric.com for a year now with a Victron SmartSolar controller, and I love it.
The bluetooth setup lets me check my panel/power all the time, it really pumps up the battery quick and overall I think it is the cheapest long term way to go.
Oh and don't worry about the panel toughness, mine gets hit with nasty desert tree branches and such all the time on top of my Treehouse camper and works great.
And I used Renogy plastic mounting feet with 3M VHB double sided sticky tape and even with 115deg ambient summer temps (which means the black camper is much hotter) you can shake the entire truck by grabbing the panel. Super easy to install.

20190601_181532.jpg
 
rayra

rayra

Expedition Leader
The above picture looks great, but be aware that panel brands and types are wired differently and most and most of the cheapest are wired in a manner than make any shade on the panel render the panel ineffective. You'll pay a premium for one that has the cells wired independent of each other. You'll still get reduced power output in partial shade like above, but you'll at least get some power.

Some folks have built mounts that will release the panel so it can be erected in full sun away from a shaded vehicle. I did something like that with a folding panel kit. It lives full time on the roof deck of my Suburban, but I can release the mounting bracket and take the panel down and set it on the ground on a long lead wire.

I've been thinking about altering / enlarging the mount and putting a fixed panel on the roof forward of the folding panel and retaining the removable folding panel to the rear.

solarpanelmount85 installed.jpg
 
R

reaper229

Active member
I bought a flexible solar panel and i installed the panel with vhb tape and gorilla tape and seals all the edges with silicone.The 100w panel is hook'up to a diy battery pack and i use it for my fride,cell phone,drone and water pump.
85596003a545e58c7be60d063be9e826.jpg
76bb74770890aa81d37b01743c28e908.jpg
3d2a3f2f6f732c46117915352cad71a8.jpg
9e1192fd1f2aba0b2245c0c3833abf86.jpg
c8162687b480cd73ddd43a632b986067.jpg


Envoyé de mon Pixel 2 en utilisant Tapatalk
 
P

pjpvi

Observer
I've had a residential panel on top of my van for probably around 10+ years now. It has taken a ton of vibration abuse off-road and still works fine. I keep waiting for it to die but it just keeps working.
 
M

monkeyodeath

Member
One downside I'm seeing is that the residential panels can be fairly heavy. Not a huge deal, and I'm finding plenty that aren't, but just FYI for others who might be considering this solution. Some of the higher-wattage (200W+) panels tip the scales at more than 40lbs.

Maybe not a big deal, depending on the application, but definitely something to consider if, as I am, you're mounting the panel on the highest point of your vehicle.

I realize that a fixed mount on top of a RTT may not always be the most ideal setup for getting sun, but seems to me like a convenient place to start. Figure I can always augment with a portable panel down the road.
 
shade

shade

Well-known member
monkeyodeath said:
One downside I'm seeing is that the residential panels can be fairly heavy. Not a huge deal, and I'm finding plenty that aren't, but just FYI for others who might be considering this solution. Some of the higher-wattage (200W+) panels tip the scales at more than 40lbs.

Maybe not a big deal, depending on the application, but definitely something to consider if, as I am, you're mounting the panel on the highest point of your vehicle.

I realize that a fixed mount on top of a RTT may not always be the most ideal setup for getting sun, but seems to me like a convenient place to start. Figure I can always augment with a portable panel down the road.
Click to expand...
Yes & no.

From what I've seen, efficient +300W panels weigh around 40 lbs, but any lighter options (multiple panels) won't deliver the same output for the size & weight. If you want +300W worth of output, residential panels are the lightest way to do it short of much less durable options.
 
M

monkeyodeath

Member
shade said:
Yes & no.

From what I've seen, efficient +300W panels weigh around 40 lbs, but any lighter options (multiple panels) won't deliver the same output for the size & weight. If you want +300W worth of output, residential panels are the lightest way to do it short of much less durable options.
Click to expand...

Yeah, that's what I'm seeing too. Nevermind!
 
You must log in or register to reply here.

Forum statistics

Threads
186,067
Messages
2,881,643
Members
225,825
Latest member
JCCB1998

Members online

Total: 454 (members: 10, guests: 444)
Top