Solar panels?

[toyota222]

Is anyone out there using solar panels on their rig? Last winter I bought a Harbor Freight 3 panel kit (45 Watts) and toyed around with it on sunny days to learn what the energy recovery entailed. I have an Idea how I would mount it and where the wiring to the inverter would go, but IS IT WORTH THE BOTHER? Hoping for feedback from someone who has tried it. Thanks!

[mulwyk]

Is anyone out there using solar panels on their rig? Last winter I bought a Harbor Freight 3 panel kit (45 Watts) and toyed around with it on sunny days to learn what the energy recovery entailed. I have an Idea how I would mount it and where the wiring to the inverter would go, but IS IT WORTH THE BOTHER? Hoping for feedback from someone who has tried it. Thanks!

I lived aboard a solar panel enabled sailboat in the 90's and have applied what I learned then to our Toyhomes now.

It could be worth the BOTHER: If you are boondocking and can live a low energy lifestyle, solar can easily supply the majority of your electricity needs. IMHO the key to solar is to keep it simple.

Our system:

We have a single 40 watt panel on our Sunrader 18 that we use for battery charging. It is mounted on the roof aft in the notch where that pathetic "luggage rack" used to be. It's not flat, but mounted at about a 20 degree angle, so if the aft end of the camper is facing south we get maximum average power...total about 200 watt-hr. per day.

That's not much power so we use very little power. We have a DC-only system (no shore power, no inverter)with all LED lights (1 watt each), a little DC TV (30 watts) and Fantastic vent-fan (25 watts at medium speed), no fridge (ice box). So if we turn on everything all at once we can run about 4 hours on the solar energy we gather during a typical day.

Edited November 13, 2011 by mulwyk

[toyota222]

Thanks, this is the kind of feedback I'm seeking...do you mind if I ask a few questions?

1. What is the dimension (area) of your panel?

2. Does the 20 degree tilt cause any noticeable air drag when driving at 55 mph (+) ?

3. How many and what kind of storage batteries do you charge?

4. If you use more than your house battery, where do you stow the other battery(s) ?

My 21' Sunrader is winterized for the season, but that doesn't keep me from planning a fishing trip to the Everglades come March. Thanks in advance!

Mick22240

I lived aboard a solar panel enabled sailboat in the 90's and have applied what I learned then to our Toyhomes now.

It could be worth the BOTHER: If you are boondocking and can live a low energy lifestyle, solar can easily supply the majority of your electricity needs. IMHO the key to solar is to keep it simple.

Our system:

We have a single 40 watt panel on our Sunrader 18 that we use for battery charging. It is mounted on the roof aft in the notch where that pathetic "luggage rack" used to be. It's not flat, but mounted at about a 20 degree angle, so if the aft end of the camper is facing south we get maximum average power...total about 200 watt-hr. per day.

That's not much power so we use very little power. We have a DC-only system (no shore power, no inverter)with all LED lights (1 watt each), a little DC TV (30 watts) and Fantastic vent-fan (25 watts at medium speed), no fridge (ice box). So if we turn on everything all at once we can run about 4 hours on the solar energy we gather during a typical day.

[mulwyk]

Thanks, this is the kind of feedback I'm seeking...do you mind if I ask a few questions?

1. What is the dimension (area) of your panel?

2. Does the 20 degree tilt cause any noticeable air drag when driving at 55 mph (+) ?

3. How many and what kind of storage batteries do you charge?

4. If you use more than your house battery, where do you stow the other battery(s) ?

My 21' Sunrader is winterized for the season, but that doesn't keep me from planning a fishing trip to the Everglades come March. Thanks in advance!

Mick22240

Hi Mick:

1. My Sunrader is also under a tarp right now so I can't measure, but the panel is roughly 4'x1' or 4 sq.ft. area.

2. There's a roughly 5 inch by 12 inch "notch" in the aft part of the Sunrader roof (I think it's there to stiffen the fiberglass), the panel is tucked into that notch space so it's not exposed to the slipstream. If I can figure out how to do it, I'll post a picture of the mounting. You'll lose maybe 30% of your panel output by mounting it flat, but that might be better than having it blow off the roof or having the drag cut into your campers miles per gallon.

3. I have a single DieHard Marine Starting battery, size 27. I use an identical battery for the engine starting battery...a couple times a year I switch batteries so the house battery becomes the starting battery (seems to make them last longer, I don't know why).

That March trip to the Everglades sounds like great fun!

Bob

[wistoy]

I have used a 15 watt panel in the past, with limited use it was able to trickle chage the battery, was good for week end trips, Unfortunatly I step on it installing my cover and broke it. I installed a new 70 watt SIG panel this spring, it word GREAT, even charges in the shade and on cloudy days, Running lights, water heater, and an inverter for a CPAP. we had no troubles camping for a week with out shore power, It rained 5 of the 7 days, and was cloudy the other 2.

The panel is mounted flat on the roof between the 1st and 2nd roof vents, Panel is about 20" by 40", and I ran the wires down the fridge chimny chase, with a digital controler mounted inside by the dinnet, the down to the battery. I think a good controler is importaint to maintain, monitor, and properly charge the battery.

[mulwyk]

I have used a 15 watt panel in the past, with limited use it was able to trickle chage the battery, was good for week end trips, Unfortunatly I step on it installing my cover and broke it. I installed a new 70 watt SIG panel this spring, it word GREAT, even charges in the shade and on cloudy days, Running lights, water heater, and an inverter for a CPAP. we had no troubles camping for a week with out shore power, It rained 5 of the 7 days, and was cloudy the other 2.

The panel is mounted flat on the roof between the 1st and 2nd roof vents, Panel is about 20" by 40", and I ran the wires down the fridge chimny chase, with a digital controler mounted inside by the dinnet, the down to the battery. I think a good controler is importaint to maintain, monitor, and properly charge the battery.

70 watts! Nice. And a digital controller? Sounds like a great system. I'd love to see pictures of it.

I made my own "controller" out of $20 worth of eBay parts...switch, circuit breaker, ammeter... good enough for a little 40 watt panel, but 70 watts would instantly peg my ammeter and then, seconds later, poof!, pop the circuit breaker.

but then, CPAP? Sorry, I should know that one,....maybe you could remind me what that means?

Below is a picture of the panel angle mounted on the roof notch of 18' Sunrader

Edited November 14, 2011 by mulwyk

[bajadulce]

I lived aboard a solar panel enabled sailboat in the 90's and have applied what I learned then to our Toyhomes now.

Nice! How fun was that. Being out on the ocean is about as far offgrid as you can get!

@ is it worth it?

The 1st step in designing a solar system is to access what you need and how much you need to recapture. If your battery storage is able to be topped off (shore power or driving, or perhaps quick charge via a generator), then no, adding solar wouldn't seem worth it.

While you can never have too much solar , it's a drag if your system can't recapture your demands. Granted each day will have different demands, some pulling more juice and some days maybe nothing at all, your system should recapture everything you would use in a day if you want to be totally independent.

For a few hours of lights, a radio (possibly one of those modern day mp3 players) running all day, and a burst of inverter power for mixing those margaritas in your blender, you'd probably require about 10-15 amp hours of regain. A single 75 watt panel mounted flat on top of your roof charging a single coach battery will probably be all that's needed for this and pretty worry free in terms of battery draw on a daily basis.

Things get a little more involved when you have something that can't be shut off to conserve energy such as a DC marine refrigerator. If your system can't regenerate this, your battery will eventually be toast. If you like to tote a laptop around and/or watch movies/TV etc, things can really start piling up quick and you'll start looking into parabolic mirrors and wind turbines! Kidding.. sort of. Wind generators are actually pretty common on sailboats and I've seen a few outside on larger RV's boondocking on the Sea of Cortez as well.

Myself, like mulwyk's rig, is totally DC dependent (no shore power charger etc) tho I do have a small inverter for my laptop, which ironically is then converted back to 9vdc or something like that with its own ac/dc converter! Many years ago we used to go to extremes to keep things 12v such as appliances and gadgets, but today's inverters are pretty damn efficient.

Anywho, one thing to note for RV'ers in terms of mounting them flat on your roof, is the typical plastic panel box usually has a profile larger than the panel's frame and will limit how close you can install them to your roof. While having a panel further away from your roof probably helps with cooling (panels are more efficient when they're not as hot), the further away from your roof, the more wind resistance. Of the few different models of panels I've looked at, all of those plastic boxes could easily be shaved down considerably allowing for a much tighter fit. Here's a snapshot of my own panels (2 older siemens 75watt used panels on ebay about $200 a piece shipped to door). The roof of my camper was actually sized to fit the panels in keeping with the "always build backwards from your needs" motto of solar. haha.

Here you can see the plastic box has been shaved quite a bit (black box in middle right)

Tight fit to roof. There's room for one more panel if should need to expand. Hangars are already there actually. Btw, those cheap galvanized sheetmetal angle brackets (about 60 cents at home depot) work pretty well for my application. Grinded/Glassed to the camper w/o any screws etc. If you have an aluminum camper, probably would be a good idea to isolate the panel from the hangar with a bushing of some sort.

K probably more info that you were looking for.

[acudoc]

Here som epics of 120 watts. PLENTY. Find them used on craigslist.

Nice! How fun was that. Being out on the ocean is about as far offgrid as you can get!

@ is it worth it?

The 1st step in designing a solar system is to access what you need and how much you need to recapture. If your battery storage is able to be topped off (shore power or driving, or perhaps quick charge via a generator), then no, adding solar wouldn't seem worth it.

While you can never have too much solar , it's a drag if your system can't recapture your demands. Granted each day will have different demands, some pulling more juice and some days maybe nothing at all, your system should recapture everything you would use in a day if you want to be totally independent.

For a few hours of lights, a radio (possibly one of those modern day mp3 players) running all day, and a burst of inverter power for mixing those margaritas in your blender, you'd probably require about 10-15 amp hours of regain. A single 75 watt panel mounted flat on top of your roof charging a single coach battery will probably be all that's needed for this and pretty worry free in terms of battery draw on a daily basis.

Things get a little more involved when you have something that can't be shut off to conserve energy such as a DC marine refrigerator. If your system can't regenerate this, your battery will eventually be toast. If you like to tote a laptop around and/or watch movies/TV etc, things can really start piling up quick and you'll start looking into parabolic mirrors and wind turbines! Kidding.. sort of. Wind generators are actually pretty common on sailboats and I've seen a few outside on larger RV's boondocking on the Sea of Cortez as well.

Myself, like mulwyk's rig, is totally DC dependent (no shore power charger etc) tho I do have a small inverter for my laptop, which ironically is then converted back to 9vdc or something like that with its own ac/dc converter! Many years ago we used to go to extremes to keep things 12v such as appliances and gadgets, but today's inverters are pretty damn efficient.

Anywho, one thing to note for RV'ers in terms of mounting them flat on your roof, is the typical plastic panel box usually has a profile larger than the panel's frame and will limit how close you can install them to your roof. While having a panel further away from your roof probably helps with cooling (panels are more efficient when they're not as hot), the further away from your roof, the more wind resistance. Of the few different models of panels I've looked at, all of those plastic boxes could easily be shaved down considerably allowing for a much tighter fit. Here's a snapshot of my own panels (2 older siemens 75watt used panels on ebay about $200 a piece shipped to door). The roof of my camper was actually sized to fit the panels in keeping with the "always build backwards from your needs" motto of solar. haha.

Here you can see the plastic box has been shaved quite a bit (black box in middle right)

Tight fit to roof. There's room for one more panel if should need to expand. Hangars are already there actually. Btw, those cheap galvanized sheetmetal angle brackets (about 60 cents at home depot) work pretty well for my application. Grinded/Glassed to the camper w/o any screws etc. If you have an aluminum camper, probably would be a good idea to isolate the panel from the hangar with a bushing of some sort.

K probably more info that you were looking for.

[wistoy]

A CPAP is a medical divice for sleep apnea. runns all night, incl a small humidifyer, and computerised blower to keep air in your lungs

70 watts! Nice. And a digital controller? Sounds like a great system. I'd love to see pictures of it.

I made my own "controller" out of $20 worth of eBay parts...switch, circuit breaker, ammeter... good enough for a little 40 watt panel, but 70 watts would instantly peg my ammeter and then, seconds later, poof!, pop the circuit breaker.

but then, CPAP? Sorry, I should know that one,....maybe you could remind me what that means?

Below is a picture of the panel angle mounted on the roof notch of 18' Sunrader

[Totem]

I recently used my Sunrader as a Deer Camp for 4 days and nights in northern Michigan for High Power rifle deer hunting. It got obscenely cold while there and snowed. At night the Temps were dropping to 21 degrees and during the day sometime a Balmy 38. Skies were sunny except for when snowing. I had purchased the Harbor freight panel system that you initially asked about in this thread on a day when it was on Sale with a 20% off coupon. I also purchased a charge controller on ebay from China for 11$ as the controller that comes with the freight set is bulky, known to have issues etc. The small China 60 watt controller I bought was 3 x 4 by 1 inches and actually fit in the Sunraders electric panel with no modifications.

This also allowed me to wire it into the extra fuse accessory slot directly. as for Mounting, as a Sunrader owner I could not bring myself to drill a hole in the pristine fiberglass roof. a $2.00 solution from the drugstore instead worked a miracle; I bought a set of suction cups for mounting shower hangers (pulled off the hook) and popped the suction cups into the holes of Frame that came with the panel set from Harbor Freight. Bam, the frame squished down and was on there good, especially after the panels were in the frame. I also had the Harbor frieght 2 stroke lunchbox generator on this trip as I had no prior solar experience; ended up selling it to another hunter while there after 2 days of using the solar setup. I was amazed at the performance.

People trash talk the Harbor system because its Amorphous however I would caution those that do for one main reason; clouds. poly and mono just do not put out on cloudy days. I can say this of the setup; the sun was not solid all days more cloudy than not yet the system always had the Battery displaying 14.5 - 16 Volts! This tells me a couple things; it was working great and checking the Charge controller revealed an excess power that went un-stored as it limited the battery to 16. I only have 1 coach battery (marine grade). My rader still has the old stock converter for 30 Amp hookup; so i wired a 650 W inverter into it at the service panel and then plug the hookup into that. I know what everyone will say to this; endless loop. Well, the setup in sunlight almost held its own and would easily run for 45 minutes before I would shut inverter down at 12.3 Volts reading while using a laptop, playing some music and watching TV for lunch, then it was back off to the woods to kill bambi.

By the time I returned from hunting in the evening the battery was fully charged reading 13.1 V. Then the torture of the battery would begin; My Rader still has the stock propane tank (horizontally mounted to frame). I have replaced all the coach lightbulbs with LEDs; I can have them all on at night and their net draw is less than one regular filament light bulb's draw.

We just plain left the lights on at night so that we could clean guns, find beers, cook etc. the Heater ran and was set at 65 degrees all night, 55 if we were out bon firing. I think the stock horizontal mount long LP tank must be more efficient propane wise than some folks grill tanks mentioned in the forums because we had the heater on non stop at least at 55 to help keep lines warm and water from freezing. We dumped the crapper when needed at the warmest point of the day after pouring a gallon of hot water into the crapper and also the sink to help thaw. had NO problems this way. I've heard people say their toys furnace kills a lot of propane per day but I did not observe that; I after 4 days and nights my tank was only down 14%! In the morning the battery read 11.9 to 12. and was at the cutoff threshold of the controller but the sun was comming up and soon the voltage was back into the 12s by breakfast at 10:30.

Looking at the setup I See two ways to immediately improve it. No, not another battery; I'm not running a dishwasher here just laptop and small tv. I think I need to wire a switch on the inverter to the run off probes of the solar controller instead of the battery. That will mean the excess solar power will run the inverter and no loopback charge waste from the old stock converter. I still want the loopback setup (hence a selector switch) however because it allows me to run full barrel off of the alternator using the engine as a generator while idling.

Speaking of which; my crappy Auto Zone 65 watt alternator just ain't cutting it. I'm gonna shell out the $450 for the powermaster I think. finally the one thing I did notice at nights in Northern Michigan are the winds. They were always in the 20 mph range or better and I mean each night. The small chinese controller has inputs for a wind turbine also I noticed....a quick check of ebay revealed a 55 watt low wind turbine thats operating specs were 8-25 mph and a high speed one that was 15-45 mph. I'm thinking I will try the low speed one, mounted on a telescoping flag pole. This setup in theory should run me like a champ though I must admit theres nothing wrong with my setup now other than the fact each night takes away one of the 100 charges one would expect to get out of a marine grade battery.

Hope this blog helps yall.

-Totem