Solar without drilling any holes

[DrJ]

I've wanted to introduce myself to this great community and say thanks.
I have spent months pouring over your posts and ideas. They have been the inspiration for several
modifications I've made to my FWC Hawk.

You guys are truly amazing and have lots of fantastic ideas!

I had a success with solar power that I will share.
You'll have to forgive me if my pictures don't post just right - still learning this process.

The newer FWCs that are set up with a prewired solar plug make life really easy for addition of a solar panel (or 2 in my case). However, I did not want to drill any holes in my roof that could create a water problem down the road. So I went with this idea instead - here's the stats.


220 watts of solar panels (100 watt panel and 120 watt panel)

flexible flat panels made it easy to glue them to the roof (after making sure they work of course!)

wired the panels together using MC4 branch connectors

MPPT Tracer 2210RN Solar Charge Controller for 20 amps

MT5 remote meter to keep track of my panels and battery



The total cost for the install was:

solar panels - $200 for 100 watt, $235 for 120 watt

wiring and MC4 connectors - about $25

MPPT charge controller - $140

MT5 remote - $45

I think my entire project was around $650.


With it I can get 7-10 amps per hour at 14.4 Volts or higher as determined by charge controller.

Even in the winter with poor sun exposure I have been getting about 4-5 amps of charge.

It allows my batteries to always have plenty of charge and run what ever I need to at this point.

The entire project is fairly straightforward and cheaper than the factory install. Plus I was able to get MPPT charge controller and more solar power. I have the dual battery set up in my Hawk. The wiring on the roof needs to be cleaned up a little bit, but the system works great. No problems with wind moving those glued on panels - I live in Southern Idaho and get our fair share of wind. They stay on great.


View attachment 18292

 

[craig333]

Nice setup.

 

[brianjwilson]

What panels are you using? They look like the flexible base with rigid cells placed on them?

 

[ETAV8R]

Nice work. Welcome to WTW. Do you only hook these up while in camp?

 

[DrJ]

They were flexible solar panels I ordered from eBay.
I believe they were made by Sacred Solar.
There are always some for sale on eBay, but every once and a while you can get them on auction for pretty cheap.

I'll attach a picture with the specs on the 120 watt panel.
I'd actually recommend the 120 watt panel over the 100 watt panel if you can get them.
If you can use the MPPT charge controller, it can accept a higher voltage - which the 120 watt panels can send.
This meant loss power loss across the wiring and more amps to my batteries. It's just more efficient.

The panels stay on all of the time. I took the camper off for a little while when I installed the panels to make it easier to reach everything. The Hawk stays in a storage unit now when it's not on the truck.

 

[Rob in MT]

Looks, good. I like that it's flush with the roof, for tree branches etc. I've read that not having a space underneath diminishes efficiency somewhat, but this looks like a good tradeoff. I saw Homedepot has 100w panels that are 20" by 40", and weigh 6 pounds!

How did you glue them down?

 

[DrJ]

There is an added benefit of it being very lightweight and aerodynamic.

I doubt the two panels and wiring together were more than 15 lbs.

The flexible panels are available from several different vendors.
Renogy solar has the 100 watt panels for $200.

http://www.renogy-store.com/mobile/Product.aspx?ProductCode=RNG-100DB

You might consider the 120 watt panels and MPPT controller if you needed more power.
The extra 20 watts is nice, but the real added benefit is the increased voltage.
The 120 watt panel can deliver power at 22 Volts instead of 17-18 volts. This makes the power loss much less over the wiring.

If I had to do it again, I would have used 2 120 watt panels.

 

[brianjwilson]

I have read that the individual cells on these types of panels can get distorted and cupped, from the heat and lack of airflow beneath them. So I will be interested to see how you like them longer term or if it is even an issue.

I really like the flexible adhesive uni-solar or global solar panels personally. The downside is that they are much larger for the wattage, and heavier. But they are much more durable and supposed to work better at lower sun angles.

 

[DrJ]

I spent a week in Nebraska and keep track of my solar preformance. They panels performed fantastic and keep me with fully charged batteries every day. It was quite cold at night (35 F) and my heater ran a lot so I was happy with the extra power. I even opted to run my 3 way fridge on 12 volt DC power just to see if it could keep it. I wouldn't recommend doing this without some serious battery or solar back up, but it seemed to keep up just fine for the day. I was pretty sure it wouldn't make it through the night, so I went back to propane at night. Here is the read out with the fridge on DC power. It was a sunny day and I had great sun exposure at the time - but I'm pretty thrilled with the MPPT charge controller and the amps the panels are putting out. 13.7 amps at 13.3 Volts is great. After a while the volts increased to 14.5 Volts and the amps dropped to around 10.

 

[RC Pilot Jim]

DrJ,
what glue type and manufacture did you use?

 

[DrJ]

I bought them through eBay. Here is a similar product:
http://www.ebay.com/itm/141374996655

I've also bought other solar products through Renogy Solar and they sell a similar product.
Renogy® 100W Monocrystalline Bendable Solar Panel by Renogy http://www.amazon.com/dp/B00IK19VF6/ref=cm_sw_r_udp_awd_8VG8tb133JB8R

If you do it with the prewired FWC wiring it's pretty easy. I would recommend, if you want more than 1 panel, to use the 120 watt or higher panel. They send a higher voltage to your charger and there is less voltage drops through the 14 gauge wire.

I have 1-100 watt and 2-120 watt panels. Total of 340 watts. Very little voltage drop because it sends the power at 18-22 volts most times. I've run my 110 litter compressor fridge, 63 quart ARB as a deep freezer and fully charged the house batteries all at the same time with this kind of set up. It works great for me.

I just used a construction adhesive that was good with plastic and metal. I'm sure several different types of adhesives would work.

 

[RC Pilot Jim]

Thanks