Adding Solar Panels

[RockyMtnRay]

I placed an order today with RV Solar (http://www.rvsolarelectric.com/inform.htm) for their "Jumbo" (120 Watt) Solar Kit plus an additional 50 Watt panel. The kit comes with panel, 30 feet of UV resistant wiring, and a 16 amp charge controller. I had them add an extra 20 feet of wire to be confident of getting all the way to the battery compartment in the back of my TM (2720SL). Total came to $950 and since that was close to their free shipping minimum of $1000 (and I'm a really nice guy :)), there was no shipping charge.

After discussing the TM's roof construction with the sales rep, he recommended pop riveting each panel's Z-mount (4 per panel) to a square sheet of aluminum stock (each at least 4 to 5 inches square) , then glueing the squares to the roof with either a marine adhesive or liquid nails. He said the marine adhesives (Plexus?) are stronger, more water resistant, and cure to a clear (or white) color. Now all I gotta do is find some marine adhesive in this town-of-very-few-boat dealers (or order online). Suggestions on the adhesive (and sources) would be most welcomed.

The plan is to mount these panels lengthwise in parallel on the curb side of the TM (with the shorter, 50 watt panel toward the center.

Will post more (and provide pictures) when the parts come in next week.

[Sinclue]

Ray,

Some sources for Marine sealants(online): West Marine, Boat U.S., and SailNet. Others on this board have used liquid nails with success.

Sounds like a good permanent installation. I think I would mount the heavier panel in the middle. It seems to me that maybe the weight on one side or another might result in some torquing of the shell when you open or close (possible scrapping or hanging up).

Remember that wherever you mount them you'll want that spot to be located to likely receive the most sunlight. If you are in hot places that makes for more heat on that part of your rig (and inside too).

jim

[RockyMtnRay]

Thanks muchly for the suggestions...I just checked the 3 on line marine stores and 'twould appear the strongest adhesive they're offering is an epoxy. Suspect I could find something at least that good locally so tomorrow will be a day to prowl the hardware stores.

As for mounting the panels toward the side (vs the center of the roof), I don't think that will be a problem as the weight of the awning (which is about twice as heavy as these solar panels) is totally on the curb side of the front shell yet there is no torqueing or twisting of the shell as it is raised and lowered. I'll certainly keep your caution in mind before I permanently glue the mounting pads to the roof & am planning to temporarily mount them with duct tape and do a bit of experimentation to make sure the shell raises and lowers properly. I'm sure I'll have to adjust the torsion bars a bit anyway and if there is some twisting, will see if preloading the curb side a bit more takes care of it. Also, I'm quite fortunate in that The Car Show (my TM dealer) is only a 20-30 minute cross-town drive away and has been more than happy to capably answer questions over the phone.

As for heat & sunlight issues, my situation is quite a bit different than most folk's. About 99% of my camping is done at elevations above 8000 feet and probably 60% of it is at elevations above 10,000 feet...so the temperature even in direct sunlight is seldomly much over 75 degrees. And since the forests at those elevations are almost entirely skinny/scrawny pine trees (largely lodgepole pine)...or equally scrawny aspen trees, there's effectively zero shade over the trailer in any campground that I've been in between roughly 9 am and 3 pm...even in the campsites that are labeled as "shady". Soooo I"m really not concerned about positioning panels (or even the trailer) with regard to shade from trees. However, because the mornings in Colorado's mountains are almost 100% likely to be clear and the afternoons are almost as likely to be cloudy (because of the almost daily thunderstorm formations), I sorta pay attention to whether or not the campground as a whole will get morning sunshine.

[RockyMtnRay]

Bill...

I did this sorta scientifically by using the handy-dandy worksheet that RV Solar has on their website (http://www.rvsolarelectric.com/custom.htm). I camp solo about half the time, the rest with one companion...but in my case that's not the major determinants of electrical usage. My electric usage comes mostly in the following categories:

--As noted before, I mostly camp at high altitude where nighttime temperatures are often in the 30s even in mid-summer. And I'm usually up well before dawn and often run the furnace for an hour or more in the mornings, sometimes for half an hour in the evenings. Figured I'd need about 15 amp-hours just for the furnace.

--Assumed I'd probably use other electrical devices (in particular the water pump) to the tune of around 4 amp-hours each day.

--I like a LOT of light...especially when I'm trying to wake up and get going in the morning. If I have my druthers (and the juice to do it), I'll simultaneously turn on most of the TM's overhead lights...and both of the "elegant" lights. Figured I'd need around 15 amp-hours for 2 to 3 hours of lighting.

--As a self-employed software developer with never-ending deadlines and client tech support requirements, the only way I can get away (even for 2-day camping trips) is to bring my laptop along. Every day I have email, a check on my servers (I run several database servers out of my home office), some development work, etc. Since I use my cellphone as a wireless modem at 14.4K (max), file & email uploads/downloads, web browsing, etc. take quite a bit of time. All in all, I figured about 2 to 3 hours or roughly 16 to 24 amp-hours to power the computer each day.

--Miscellaneous...like recharging my digital camera, cellphone, etc....about 4 amp-hours.

Add it all up and my daily power use (if I have all that I can get) is around 70 amp-hours. Add in a fudge-factor for battery and line-loss and it comes up closer to 80 amp-hours.

Based on the assumption that I'll have good sunlight for about 6-8 hours a day (some days more, some less because of afternoon clouds), I calculated that I'd need a panel array that could generate about 10 amps. Based on RV Solar's offerings and pricing, that turned out to be their Jumbo 120 watt Kit (7 amps of generation) plus a second 50 watt panel (3 amps of generation). Their Kyocera 50 watt secondary panel was only $20 more than a 40 watt panel; but the 80 watt was $100 more than the 50 watt. It seemed that for my needs the sweet spot in terms of watts/dollar system cost (including controller, wring, mounts, etc.) was at 170 watts total.

I'm guessing the total weight of roof mounted components will be somewhere around 50 lbs. This is partly from bits and pieces of info I've picked up elsewhere and partly from the shipping weight of my order (60 lbs) The RV solar price list shows 12 lbs each for their kits but I think that's probably way too low.

I personally am kinda doubtful that a 50 watt panel would be enough to recharge your battery every day unless you're extremely frugal with power usage...and have cloud-free skies and a shade-free location for your panel nearly every day. A 50 watt panel is only going to generate around 3 amps in full sunlight under normal temperature conditions.

[Larry_Loo]

Ray,

I've had quite a bit of experience with adhesives during the manufacture of my woodworking tools. You mentioned the use of epoxy glue to mount your solar panels to your TM's roof. I can see a couple of problems with using epoxy for this application. The first is that epoxy resins begin to soften at around 140 deg. Fahrenheit temperature. The second is that epoxy resins slowly deteriorate with exposure to sunlight. They become chalky and powdery. This latter result can be prevented or retarded by painting the glue lines with some kind of a durable paint, perhaps one with a UV light inhibitor. However, using this kind of adhesive in a location for which you will try to maximize sunlight exposure, and therefore heat from the sunlight, may not be the wisest thing to do.

[Happytrails]

Whoh Ray, be very careful of the placement, you WILL have to adjust your torsion springs by adding them, if too heavy, might have to buy all new ones as I was told by Jimmy Davis at the TM plant when I was considering adding roof air. (That's about 100.00 a pop, x4, if it's that much heavier a setup). Chosing to find a side air unit which mine was made for, I simply removed my awning, (because I was thinking about getting a new one, and didn't want to drill any holes in all the new aluminum I added in the top before that decision was finalized), and see a SIGNIFICANT difference in how my TM closes, opening's fine tho I'm sure it scrapes a bit, the seals for the most part protect it, but when I go to close it, (by another member of this board's description, which fits it best), it calliwhumps down, scraping all over the awning side because it's adjusted PRECISELY to the weight of the awning that is supposed to be there! (no, the springs aren't "that" forgiving, they have to be adjusted for like every 10lbs or maybe more, not sure, but to be on the safe side, lets say 10lbs). Just be very careful Ray about the weight distribution as you'll wind up scraping up your windows and such if you're not aware of that. I would suggest before you glue them down, do your best to distribute the weight equally, and try opening and closing the top and see how it goes, never mind if it gets hard to open for the extra weight, that can be adjusted later, just make sure it opens up SMOOTHLY.....without rubbing or "callywhumping".

Next, may I suggest "Gorrilla Glue" as an adhesive? You can seal them with silicon still, or whatever ya want, but that stuff is rock solid, and won't give.....no matter what, and if ANYONE in this room knows a way of removing it in any way, PLEASE let me know, I have a few dribbles I can't even scrape off with a knife it's that strong! (Body shops use it in fact to secure molding and such it's so strong!) Might have to get my Dremel tool after it I guess, and paint underneath when I hit aluminum? LOL (Nah, I'd much rather simply find a solvent that would get rid of it rather than do that). It's a bit expensive, but worth it, and will bond aluminum to aluminum, or whatever with NO WORRIES ABOUT ANYTHING coming lose! lol Lets put it this way, dunno what TM is using to glue the aluminum in there now, but after removing the wood from mine to replace out, I peeled back the stretchy glue from the aluminum like a sunburn peeling. Gorrilla Glue, um, I think the area would have to be cut out, then the aluminum skin probably could not be removed in one piece with a chisle and a hammer even! Dunno much about epoxy's, but this stuff bonds to aluminum WELL! (And it looks so innocent simply sitting in the bottle like a typical Elmer's glue only brown). LOL I can CERTAINLY speak from experience on that stuff!

Anyway Ray, please keep the things I said in mind while doing your project, and you should be ok....(Especially about the weight thing)......Anyway, hope I'm of help!

Happytrails........

[RockyMtnRay]

Whoh Ray, be very careful of the placement, you WILL have to adjust your torsion springs by adding them, if too heavy, might have to buy all new ones as I was told by Jimmy Davis at the TM plant when I was considering adding roof air.

Already ahead of you there, HT. When my dealer installed an awning this spring, they found the existing torsion bars couldn't be adjusted enough to handle the extra weight. So they went ahead and put in the heavy-duty bars and I now have a heckuva lot of torsion adjustment available.

I would suggest before you glue them down, do your best to distribute the weight equally, and try opening and closing the top and see how it goes, never mind if it gets hard to open for the extra weight, that can be adjusted later, just make sure it opens up SMOOTHLY.....without rubbing or "gallywhumping".


Well, as noted above, I'm certainly not going to permanently attach the panels until I'm satisfied with both the panel position and torsion adjustments (will use duct tape to temporarily mount them). There are pros and cons to both center mounting the panels and side mounting them. Center mounting will balance the weight between the two sides...but since the awning is one side only (and weighs a lot more), that is not necessarily required. Side mounting will allow me to use the top of wall aluminum structural tube with screws (vs adhesive)...and it will help the overall side to side weight balance of my TM (my street side weighs nearly 200 lbs more than my curb side because all the water tanks are on the street side). I will discuss this issue with Jimmy Davis before finally settling on a location. At the moment though, I'm leaning toward mounting them along the curb side right next to the awning and adjusting the tornsion bars as needed to balance the weight.

Next, may I suggest "Gorrilla Glue" as an adhesive? You can seal them with silicon still, or whatever ya want, but that stuff is rock solid, and won't give.....no matter what, and if ANYONE in this room knows a way of removing it in any way, PLEASE let me know,

I spent nearly all of this past weekend researching structural adhesives and found that Loctite Corp's website had a treasure trove of information...see http://www.loctite.com/literature/. A lot of it is pretty technical but since I have a Masters Degree in Chemistry I found it as fascinating as a great novel....but the phrase "Your Mileage May Vary" might apply for other people. ;)

To make a very long story short, there are basically 4 or 5 classes of applicable adhesives...epoxies & urethanes, 2 part-no mix acrylates, silicones, and cyanoacrylates. Only the epoxies, urethanes, and 2-part acrylates have the sheer strength, weather resistance, peel resistance, etc. to be suitable for attaching solar panels to the roof of the TM.

Gorilla Glue is a urethane class adhesive. As you note, urethane adhesives are (or can be) extremely strong. However, the "curing" process of urethane adhesives is dependent on moisture diffusing through the polymer. For you in pretty darn soggy Virginia this is not going to be a problem as you have lots and lots of atmospheric moisture nearly all the time. For me in typically arid Colorado (relative humidities often way below 10%), this could be a very big problem and there's a distinct possibility that Gorilla Glue would not form a strong bond here. I'm not sure if they even sell the stuff hereabouts.

As Larry notes (and was confirmed by the Loctite literature), epoxies are not very tolerant of temperatures over 140 F...and on a hot, sunny day the roof of the TM is quite likely to exceed that.

Soooo, I'm currently focused on the 2-part acrylates like Loctite Depend. This class of adhesive is extremely strong (2000 to 3000 lb/sq inch sheer strength) and is very heat tolerant (at least 260 degrees). It's also tolerant of uneven bond gaps and even some contaminants on the surfaces. And unlike epoxies, there's no need for precise ratios...apply the resin to one of the surfaces to be bonded and an activator (or catalyst) to the other, stick them together, and in about 2 minutes the bond is "fixed". Badda-bing, Badda-boom. The problem is that these are very, very pricey adhesives (around $25 for an eensy, weensy, teensy, tiny 25 ml syringe of the resin...though that's supposed to be enough for 200 sq. inches) ...and not sold by just any old hardware store. I'm hoping that one of the Loctite distributors here in Colorado Springs (we have about 6) will have the stuff but, if not, I can get it from at least 2 on-line adhesive merchants.

Based on case studies I found on the internet, I'm sure this stuff is strong enough...one company is using it to attach micro-vortex generators to the wings of aircraft (instead of rivets). And the folks who run the particle accelerators at the national nuclear labs use it to attach the accelerator/focusing magnets to the tubing (an incredibly demanding application).

[RockyMtnRay]

Allrighty, time to post an update...the panels and parts arrived yesterday and today I spoke with Jimmy Davis at TM about mounting and with a local adhesives expert about adhesives.

First the panels...the 120watt panel is 26"X58" which is pretty darn big when you actually have it in your hands! The 50 watt is a much more manageable 26"X26". Although kinda unwieldy, the weights are quite reasonable...the big one is about 25 lb, the smaller around 11 lbs. They come with just a connection box on the back (no wires attached) so I haven't yet had a chance to hook them up to the charge controller and a battery and put them in the sun for some testing (will do that on Sunday after I get a couple of hot deadlines met). I can say that the folks at RV Solar did a really good job of packaging them for shipment....lots of sturdy spacers and tape and double boxing.

Jimmy Davis was right up front about Solar on TMs...the factory doesn't do this so he doesn't have much knowledge on the subject or recommendations on best practices. He did, however, say that it really doesn't matter where the panels are mounted on the roof (center or edge) because the total weight is relatively low (only about 36 lbs) and that any side-to-side weight imbalance can easily be handled by tweaking the torson adjustments (especially since I have the heavy duty torsion bars but don't have the roof air).

He also said that there are actually two square aluminum tubes at the top corners of the roof in the newer TMs...one in the edge of the roof section and one in the top of the wall section...and these are stacked vertically (roof over wall). Thus, if I wanted to mount the panels on the edge of the roof, I'll be able to sink longer screws down through two structural elements.

I asked if there might be a problem with glued-on panel mounts causing the TM's skin to delaminate from the foam core and he said he'd never heard of that happening to anyone.

Finally, he said the soft rubber strip on the top edges is basically cosmetic only...it hides the screws that actually attach the roof to the wall...and can be cut away as needed to mount the solar panel z-brackets. Oh...and they use a regular clear silcone caulk on their screws to keep the water out.

Finally, had a great discussion with a sales rep at a local branch of the Fastenal Corp (http://www.fastenal.com) (these guys are the experts in fastening things together!) and after I explained my requirements he said he'd do some research and get back to me. Welll...after he talked to a Loctite tech rep, it turns out they recommend the same adhesive I thought would be best: Loctite Depend (http://www.loctite.com/datasheets/tds/Product_330.pdf). They don't have it in stock but will have it by Monday. About $32 for a kit with 25 ml of adhesive (and tiny spray can of activator)...a few bucks more than the cheapest on-line price but I also don't have to pay shipping.

Soooo...the plan now is to mount the panels along the curb (door) side top edge right next to the awning. I'll use sheet metal screws to attach the Z-mounts to the underlying tubing on that side of the panels. And on the other side of the panels I'll rivet 5"X5" aluminum plates (1/8 inch or thicker) to the Z-mounts and bond the plates to the top of the TM with the Depend adhesive.

Before final mounting there'll be some testing and torsion tweaking with the panels affixed with duct tape.

[Happytrails]

Yes Ray, he was correct about the tubing in the wall and roof sections. Did he say anything about any wood being used in there? In mine, I had to replace the 1.5" wood that had been rotted, with 1" of aluminum tubing, and .5" thick wood strips simply added in there as a filler to fill the gap that would have existed had I only used the aluminum. I imagine they're simply just using the aluminum tubing now tho which is a 1x1 square tube. If you would like to see what I'm talking about, you can see a good example of what exactly's in there JD was talking about on my web page.
http://members.aol.com/br768
Just remember, you probably don't have the wood in there, so you'll have 2" of aluminum tubing to screw down into. Though you can still use 2.5" screws as they will simply get a better bite on the last layer of aluminum in the bottom of the bottom tube, and go harmlessly down into the styrofoam in your wall section. If you use stainless steel screws, be sure to drill your pilot holes just the right size as stainless is very brittle as you well know. Hope this helps!

Happytrails........

[RockyMtnRay]

HT...

As a matter of fact Jimmie did mention that they quit using wood framing "a few years ago" and that my 2002 would definitely be aluminum tubing only.

Thanks muchly re the caution on the brittleness of stainless steel screws...I actually wasn't aware they were more brittle than regular steel! :o But, to be honest about, I hadn't given the type of screw a whole lot of thought yet (the panels came with what appear to be inch and a quarter galvanized screws). When I go to get the aluminum sheet to make the mounting plates out of, I'll see what my hardware store can scare up vis-a-vis longer screws.

[Happytrails]

Yes, I'd definately suggest using Stainless Steel, having replaced out almost every exposed screw in my TM's top shell with them myself as the old screws had hardly any threads left on them! (That can be seen on my website as well). And yes, the "brittleness" was one of those VERY hard learned lessons I learned real quick after busting off the heads on quite a few! (I probably sounded like the father from A Christmas Story during the "furnace" scene at the time)! LOL! And that is good to hear about the wood framing not being used at all, I had a feeling about that, I had to use it to fill the gaps due to the difference between the size of the wood that was in there, and the aluminum tubing. But I did treat what wood I used in there as a filler with THREE coats of Thompson's. But all in all, I'd suggest 2.5" stainless steel screws for your application where it goes into the aluminum framework for the best bite possible.

Happytrails........

[Bruce]

Ray,
I used a $1.19 tube of Liquid Nails to attach the aluminum feet for my 2 80 watt soalr panels to the roof of my TM. That was back in the spring of 2001 and since then we have spent 2 summers in our trailer and traveled out west and up into Canada and the panels are still firmly attached. It sits outside in the intense Fl. sun all day long so I know the heat doesn't affect the bond.
For my $ Liquid Nails can't be beat.
Good luck with your solar rig.

Bruce

[RockyMtnRay]

Finished the installation this past Sunday and took it out for trial campout on Monday through Wednesday (about a 300 mile roundtrip).

In the end I decided to use just adhesive (Loctite Depend) to hold down 4 mounting pads per panel (5X5 each)...it seemed much easier (and possibly stronger) than trying to use a mix of screws and adhesive. I'm glad to hear Liquid Nails seems to be working for you (which variety BTW, they make a whole bunch of different adhesives) but I was super happy with the Loctite Depend. It's incredibly strong but a snap to apply (activator on surface, glue on the other). About a minute or so to position after placing the panels on the roof, completely cured within a few hours. And totally resistant to heat, chemicals, etc. Probably was overkill...I've theoretically got around 50,000 lbs of tensile strength on each of the 4 pads on each panel...but I wanted to use the strongest adhesive available and I believe I did just that. :) And compared to the $950 I spent for the panels, charger, wiring, etc., the $32 I spent for the Depend adhesive seeme quite reasonable to me (for piece of mind if nothing else).

Panels are working as expected...I'm getting about the anticipated 11 amps of charging current in full sunshine from roughly 10:30 am to about 3 pm, with at least 5 amps of current from 8:30 am to 10:30 am and 3 pm to about 5 pm. Which is good because the nighttime temps where I was camping this week (Baby Doe CG near Leadville, CO) were in the upper 30s and lower 40s...so the furnace was on for several hours each night and early morning. And even with that amount of furnace usage...and not being at all frugal with the lights...the battery never went below 50% and was fully charged by around 2 pm each day.

The panels are even able to meet the refer's power needs! So no longer any worries about draining the house battery if I choose to make a mid-day stop for a couple of hours while running the refer on DC.

It is sooooooo nice to not have to be particularly concerned about electrical use and battery state while boondock camping....and not having to periodically stay in "RV Parks" (really RV Parking Lots) during trips because I've needed to recharge the battery. In even the nicest ones I find the distance between campsites is so unbearably small that there is really no privacy. (I like the 150 to 300 feet between sites that I typically find in NFS campgrounds here in Colorado).

Pictures to follow...hopefully sometime next week when I pull the trailer out of the garage for some cleaning.

[aldebnj]

Ray,

Any pictures yet of your installation? My wife and I are seriously considering adding solar to our TrailManor when we get it in the Spring. We have a pop up right now and have been limited to using campgrounds with utilities because of no usable water tank and the need to power breathing equipment at night. (I have sleep apnea and can stop breating at night with the gear.) The gear runs off of 120 or 12 volts. We've been staying mostly at private campgrounds and the sites have been so small. We miss the State Parks we used to stay in.

Well, any way, we are very interested in how it turns out and about how difficult it was to wire in the controller and etc.

Thanks,

Al

[RockyMtnRay]

Should have pictures in a day or three...gotta pull the TM out of the garage real soon now to do some cleaning (and install an electric tongue jack...I am soooooo tired of cranking that handle while standing in the broiling sun down here in the lower elevations).

The wiring actually wasn't that difficult...though a bit time consuming. Since the battery on my 2720SL is in a back compartment, I ran the wire along the top door-side edge of the roof of the front shell, down the the door-side back edge of the shell, down along the rear lifting arm of this shell, thence back under the floor on the door side (going underneath where the torsion bars do). I was able to utilize the screws on the back edge of the shell for cable guides; installing all the other cable guides required drilling (I spaced my guides about a foot apart).

Once I got the cable routed back under the battery area, I was able to utilize an existing hole in the floor where the grounding wire came down to get the cable into the rear compartment. Once there, it was a fairly simple matter to wire the cable from the array to the charge controller (which I mounted on the compartment wall), and then run wires from the controller to the battery. I did get a bit fancy and hooked an analog ammeter between the trailer wiring/solar controller and the battery so that I could get a better sense of how much current was going in/out of the battery under various sun conditions and usage situations.

Working very deliberately and carefully (for instance, I put a dab of silicone on each drill hole before installing the cable guide screw), the whole wiring process took about 6 hours. A fair amount of that time was spent determining the best way to proceed after each stage...."ok, now I have cable under the trailer, what's the best route to get it to the back?", "ok, now I have the cable under the battery area, what's the best way to get into the rear compartment?, "ok, I have the cable into the compartment, where are the best places to mount the controller and ammeter so that I can still get the battery in/out when needed?", etc., etc. Since so much of a TM's structure is very thin aluminum or thin wood, one must be exceedingly carefull in picking mounting points.

And I also periodically stopped and did electrical checks, cable binding and freedom checks (shell up, shell down, shell up, etc.). And since I was doing this on a very sunny day, the panels were kicking out their full output (~16 volts and 11 amps) so I also felt it was better to throw an opaque cover over them while I was cutting and hooking up wires to the various components ('tis not a good idea to be working with live wiring...an "oopsie" can produce a heckuva shower of sparks :(). Covered up, the panels produce essentially zero voltage and current.

Hmmm...I think I'll whip up a little diagram of how I did the hookups and include that with my pics. I have Visio and IIRC, it can produce an HTML page. DC electrical just makes sense to me so I can usually proceed with just a mental diagram but not everyone is so enabled.

[aldebnj]

Ray,

Thanks for the info! I will be looking forward to the pictures and diagrams.

Trust me, I know about the "shower of sparks". That's how I got the nick-name "Sparky" on one job. We were installing a new two-way radio system in an ambulance and it was my job to disconnect the line to the battery switch. I must have grounded out that wrench about 10 times.

Al

[Happytrails]

Could be worse, lol, I have a friend who earned the nickname, "moonbeam" on his job. He is an electrician, and installs the wiring in moble homes. Lol, he has "unfortunately" fallen through the roof in not one, but two moble homes! Chuckle, definately don't want to earn that nickname with a TM!!! :o

Happytrails........

[RockyMtnRay]

Ok, I've now got 8 days of camping experience with the panels and it's time for pictures and report of how well the panels have worked (see following post for the report).

First, the pictures (remembered I hadn't taken any pics until just before I put it away after my last trip, so had to shoot with only evening twilight for lighting, hence the subdued colors).

This is an overview shot looking rearward from the very front of my TM (2720SL). The 120 watt panel is in the foreground, the 50 watt panel in the background. As you can see, they take up most of the roof on that side of the trailer.

http://www.rockymtnray.us/images_general/misc/tm_solarpanel_overview_a1.jpg

And this is a shot of the details of the mountings. Attached to each corner of each panel is a "Z-clip", a predrilled, roughly eighth inch thick aluminum offset. The Z-clips attach to the panel frame with a single bolt. I attached the Z-clips to 5 inch plates of 12 guage aluminum (a bit less than an eighth of inch thick) using 2 stainless machine screws & nuts (important note: the bolts you see are NOT going into the TM's roof...only through the mounting plates). The tricky part here was drilling the countersunk holes on the back side of the aluminum plates so that I was leaving enough material for the shoulder of the screws to pull against as the nuts were tightened yet making the holes large enough that the head of the screw was flush with the bottom of the plate (to within about .05 inch). After all the screws/nuts were in and tightened, I did have to do some filing to bring the screw heads flush with the plate bottoms.

The final step was to attach the plates with adhesive to the top of the TM's roof. I used Loctite Depend...an extremely high strength 2-part acrylic adhesive (~1000 lbs/sq inch on painted surfaces) by spreading its resin on the roof (in premarked areas) and spraying its activator on the bottoms of the plates. Once the two surfaces were mated, I had about 3 minutes to do final positioning.

I suspect the weakest link here is the Z-Clip to plate screws, but so far with over 1000 miles of travel in some really windy conditions (air velocity over the roof at least 90 mph) and quite a bit of rain, the mountings are still rock solid. And, by using a straight adhesive mounting technique, I avoided having to drill any holes into the TMs roof.

http://www.rockymtnray.us/images_general/misc/tm_solarpanel_mounting_a.jpg

[RockyMtnRay]

Final report part 2: How they've done.

I've depended on the panels for power in 3 separate campgrounds.

Campground 1 was Baby Doe, near Leadville CO in mid August. My campsite had a north south alignment with fairly tall pines on its east side. I was not getting full sun on the panels until around 10:30 and learned lesson 1: If even a small part of a panel is in shade, the panel's output is reduced by at least 80% (not proportional to the percent of the panel thats shaded). The entire panel must be in full sun to reach it's rated output. To compound matters, the daily mountain thunderstorms built early in the day while I was there so I only had full sun until around 1:00 pm (about 2.5 hours). And being that this campground is at 10,300 altitude, the nights were in the low 30s so I was using around 3 hours of furnace blower each day...and freely using the lights in the evening. Total usage was around 40 to 50 amp hours per day. Nonetheless, the 2.5 hours of full sun and 6 or so hours of shaded/overcast sun were more than enough to fully recharge the TM battery.

Campground 2 was N. Michigan Lakes in remote northern Colorado from Sept 2nd to 5th. Again I had pines along the east side of the camground but started getting full sun by 10 am...and didn't have afternoon clouds until around 4 pm. Again, temps were in the low 30s at night and I freely used the TM's lights. But with more sun, the TM battery was fully charged by the time I got back from my hikes (around 1:30). So I used the extra power to recharge my laptop computer's battery, which it did in about an hour. And I STILL had gobs of unused charging power.

Campground 3 was Timber Creek on the west side of Rocky Mtn NP from Sept 7th through 10th. It is very densely forested with 50 to 70 foot lodgepole pines...so much so that I didn't get completely full sunlight on the panels at any time (the TM was in the largest clearing I could find but the sun angle at mid-day still wasn't high enough to clear the tops of the trees). To compound matters, it was overcast, foggy, and/or rainy for a good amount of all three days that I was there...maybe only 1 or 2 hours of full sunlight each day. Important lesson 2: When camping in late season, it's extra important to have a campsite that is well away from trees (especially on the south and east sides) because of the much lower sun angle.

Because of the relative paucity of full sunshine, I substantially cut my use of the TM's lights and didn't let the furnace run quite as often (thankfully the temps were in the high 30s at night). The net was I using around 40% of the battery's capacity each night and the panels were giving me around a 30% of capacity recharge. By the morning of departure, the battery was down to around 35 percent charge level...still enough to show 3 lights (including the "G" light) on the TM's battery monitor but only about 12.2 to 12.3 volts on my voltmeter.

The trip home (about 5 hours) was almost completely in full sunshine. And even though I had the TM's refer running on DC, the combination of DC current from my TV and from the panels was enough to bring the battery fully back up to 100% power by the time I got home.

Conclusions:

(1) Don't just plan your array to barely replenish each days use and assume you'll have a full day of sunshine to do this. If I have a full day of sunshine, my array will produce at least twice my average usage, probably 3 times my frugal useage. Plan instead to be able to get a full recharge in only 3 or so hours of sun; or in a full day of cloudy conditions.

(2) Plan/pick campsites and campgrounds that provide sun during the times of the day that are most likely to be sunny. "Shady" is not a good word for camping with solar panels. ;)

(3) With only the standard TM battery, 4 to 5 days of continuously cloudy weather is about the limit even with panels if the furnace must be periodically used to stay comfortable.

[Chris_Bauer]

I am seriously considering a solar kit for the TM. This Christmas we will be dry camping in Big Bend Natl Park for a couple of weeks and I know it will be cold at night. I have mentioned the Heater Buddy and the Olympian heater but think that I need to consider electrical needs too.

What is the possibility of using a non-mounted panel, one which you can move around to capture the sun?

Camping World sells a "plug and play" system. Any feedback on their system?

I am not electrical :'( and need to have someone do the wiring etc and want to keep it simple enough that no one can screw up my TM. Any advice for a "no" do-it-yourselfer would be appreciated.

[Bill]

I am seriously considering a solar kit for the TM. This Christmas we will be dry camping in Big Bend Natl Park for a couple of weeks and I know it will be cold at night. I have mentioned the Heater Buddy and the Olympian heater but think that I need to consider electrical needs too. Chris -
Have you sized out your needs? Most people seem to end up somewhere between 100-200 watts. Is it just two of you, or do you have a family?

What is the possibility of using a non-mounted panel, one which you can move around to capture the sun? There are arguments both ways. I plan to buy a solar system in December, when we go through Flagstaff, and I plan to use non-mounted panels. People put non-mounted systems on poles, but I don't know why. I plan to cobble up a tiltable frame and set up the panels on the ground (or on the picnic table, or the roof of the TM).

Camping World sells a "plug and play" system. Any feedback on their system? 'Spensive. These appear to be non-mounted systems, too. If you are fully convinced of your non-DIY status, and willing to pay for that status, these are probably fine systems. There doesn't seem to be much difference among systems. OTOH, there are only about three components in a solar system, and they are easy to wire up.

Let us know how you decide to go, and how you make out.

Bill

[RockyMtnRay]

I am seriously considering a solar kit for the TM. This Christmas we will be dry camping in Big Bend Natl Park for a couple of weeks and I know it will be cold at night. I have mentioned the Heater Buddy and the Olympian heater but think that I need to consider electrical needs too.

What is the possibility of using a non-mounted panel, one which you can move around to capture the sun?

Camping World sells a plug and play system. Any feedback on their system?

I am not electrical :'( and need to have someone do the wiring etc and want to keep it simple enough that no one can screw up my TM. Any advice for a non do-it-yourselfer would be appreciated.Chris...

Your first step really should be to determine about how much electrical power you're typically using in a given day. A good way to start is to use RV Solar's worksheet: http://www.rvsolarelectric.com/custom.htm. Once you know your usage, then you have to ascertain how much generation capability you'll need to replenish the batteries. One of the considerations that's seldomly addressed in the solar power discussions is how much of your typical day will be cloudfree. Other considerations are sun angle (this becomes a significant issue for winter camping) and whether or not your typical campsite is shaded by trees, cliffs, canyon walls, etc. All of these considerations substantially reduce the amount of power that a given panel will produce over the course of a day...so you have to buy an oversized panel array to make up these reductions.

For example, my usage averages around 40 amp-hrs each day (mainly because of the furnace and lights). My panels can generate around 90 amp-hrs if they get a full 10 hours of unobstructed summer (high sun angle) sunshine. But in real world use, I've found that because of shadows from trees, etc, I seldomly was getting much current out of the panels before about 10:30 am...and afternoon storm clouds were pretty well shutting down current generation by 2:30 pm most days. The result was I was getting only about 4 hours (or 45 amp-hrs) of recharging current in a typical day. Somedays I got more, somedays I got a lot less...but I was really glad I bought about twice what I needed in terms of generation capability.

Do your calculations and think about your usage conditions...then post your data and I'll help you determine how large (and how many) a panel array you'll need.

After that can come the decision on where you get the panel(s), whether you want to go with non-permanently mounted panels, and where/how the panels interface to your TM's electrical system. This will likely be a major purchase (mine were nearly $1000 in parts alone plus another 15 hours or so of my time to do the mounting and wiring)....so I would suggest this be thought through very carefully.

[Chris_Bauer]

Thanks guys for the help. I am currently mulling over my solar worksheet to see what my requirements will be. I also pulled out two books I had on hand, RVer's Guide to Solar Battery Charging, and Backwoods Solar Electric. They have given me some good info about electricity in general ???.

Ray, regarding your furnace use; are the hours mentioned total cycling hours (on and off based on thermostat setting)? And what temperature did you keep your furnace set at? Do you only use the one battery and if so, what kind of battery is it?

Thanks and I will keep you posted.

[RockyMtnRay]

Ray, regarding your furnace use; are the hours mentioned total cycling hours (on and off based on thermostat setting)? And what temperature did you keep your furnace set at? Do you only use the one battery and if so, what kind of battery is it?


Chris...

Those are run time hours for the furnace/blower...I did not include time when it is cycled off (the way I use it, it doesn't cycle off very much).

I set my thermostat somewhere around 65 (or lower) when I'm heating my TM. But keep in mind that my outside temperatures in early morning (when I mostly use my furnace) are typically in the 30s even in mid summer. And I let the interior of my TM drop down to around 45 during the night so the furnace has to do a lot of work just to bring the interior up to (and hold it) in the mid 60s. When I'm out camping I'm an early riser (~4 am) and early to bed kinda guy (usually before 9 pm) because of the need to do all of my outdoors activities before the afternoon thunderstorms arrive. So I hardly ever use the furnace during the day and very seldomly in the evening. But I do use it a lot in the morning before I head out for the day.

Yes, I'm operating with only one battery...the Group 27 RV/Marine unit my dealer installed when I bought my TM in June of 2002...when new it had roughly a 107 amp-hr capacity. Suspect by the end of last season that had decreased to somewhere around 80 to 90 amp-hrs due to multiple deep discharges in the two camping seasons.

[Robin]

I bit the bullet and ordered two 80 watt panels (Kyocera) and a regulator from Solar Electric in Scottsdale. With 2-day UPS, the whole thing cost me $905. They will be here this Friday.

My plan is not to install them on the roof, but instead keep them portable so I can spread them out in the sun and not worry about what direction the trailer is facing. When not in use, I'll put them in my pick-up truck.

Doug from Solar Electric makes it sound easy. We'll see - I'm pretty lame about anything that involves tools other than paper clips and pencil sharpeners. But he told me that the panels are plug and play - an orange extension cord should do it. All I have to remeber is: black is positive, and white is negative. Is that right? ???

We're taking off on November 22nd for two weeks in Utah and New Mexico. I'll let you know how long it takes me to put all that stuff together.

[Robin]

Oh yeah, I also purchased a catalytic heater - the smaller WAVE model. I have a big propane tank with a 12-foot hose, so I can set it on the ground outside and run the hose under the velcro.

[Bill]

I bit the bullet and ordered two 80 watt panels (Kyocera) and a regulator from Solar Electric in Scottsdale. With 2-day UPS, the whole thing cost me $905. My plan is not to install them on the roof, but instead keep them portable so I can spread them out in the sun and not worry about what direction the trailer is facing. When not in use, I'll put them in my pick-up truck.Robin -
I have made the same decision - two Kyocera 80-watt panels, and portable mounting. I will buy mine from Wind-Sun in Flagstaff, but the Scottsdale outfit is good, too. Did you buy a pre-configured kit, or a la carte? Did you buy ready-made mounting frames for the panels, too, or will you make your own? If buying frames, what kind did you go with? The factory-made mounting frames looked pretty pricey to me, so I may not go that way.
Doug from Solar Electric makes it sound easy. He told me that the panels are plug and play - an orange extension cord should do it. All I have to remeber is: black is positive, and white is negative. Is that right?Yup, it should be that easy. We'll be interested in whether the instructions are clear and easy, etc. I'm sure Chris_Bauer will be interested, and I certainly will. Did Doug have any comments or advice about portable mounting vs roof mounting?

Keep us posted!

Bill

[RockyMtnRay]

I bit the bullet and ordered two 80 watt panels (Kyocera) and a regulator from Solar Electric in Scottsdale. With 2-day UPS, the whole thing cost me $905. They will be here this Friday.

My plan is not to install them on the roof, but instead keep them portable so I can spread them out in the sun and not worry about what direction the trailer is facing. When not in use, I'll put them in my pick-up truck.

Doug from Solar Electric makes it sound easy. We'll see - I'm pretty lame about anything that involves tools other than paper clips and pencil sharpeners. But he told me that the panels are plug and play - an orange extension cord should do it. All I have to remeber is: black is positive, and white is negative. Is that right? ???

We're taking off on November 22nd for two weeks in Utah and New Mexico. I'll let you know how long it takes me to put all that stuff together. Robin...
As Bill is hinting at, you defiintely don't want to just lay these panels on the ground. In addition to the great possibility they'd get stepped on /run over (the panel face is glass), there's the problem of dirt on the face (cuts light) or water/corrosion getting into the connectors on the back (my connector boxes weren't sealed). IMHO, you really need to fabricate some kind of mount...ideally one that can be tipped to maximize exposure to the low sun-angle during the winter.

Bill and Robin...

A very important consideration will be devising a way to easily connect to/disconnect the panel array from the controller (which really should be mounted inside the battery compartment...my controller instructions recommended not more than 5 feet from the battery). Whatever you use for a connector should be such that it will always be very low resistance as even a couple of ohms of resistance will noticeably cut the charging current the panels will produce. The instruction booklet I got from RV Solar made a very big deal about minimizing connector resistance and ensuring the connectors stayed at minimum resistance even after being exposed to the weather for a while.

As for cabling, yeah, good quality extension cord cabling (not smaller than 14 guage) is a pretty good solution cause its quite flexible. I used the heavy-duty UV stable cabling that's best for solar (very low resistance, very well insulated) but it's very stiff and not good for a portable installation.

[RockyMtnRay]

Oh yeah, I also purchased a catalytic heater - the smaller WAVE model. I have a big propane tank with a 12-foot hose, so I can set it on the ground outside and run the hose under the velcro.I've been considering that one...I assume you're referring to the Wave models by Olympian. Keep in mind that those are low pressure heaters so you need a proper pressure regulator on your tank....or you could tap into your TM's gas lines. If I bought one of these heaters, I'd seriously consider having a gas outlet installed roughly where the wall alongside the refer meets the outside wall of my TM. It could tap into the gas supply coming up for the refer and would terminate in a quick disconnect fitting (possibly with a shut off valve for double safety). You can get quick disconnect fittings for the hose going to the Wave.

Also keep in mind that these are radiant heaters...they don't directly warm the air like many electric heaters or the TM's furnace do. Rather they warm the surface of whatever they're aimed at...you or perhaps the front wall of the TM

[Chris_Bauer]

Robin and Bill,

You're right, everyday I am one step closer to buying the panels. I will, however, wait for a trip report from Robin. It should still give me enough time before Christmas to include them in my letter to Santa ;D.

I'm just not capable of the install and am hoping that either I can find someone in the Rio Grande Valley or I can use them portable like Robin has intended.

Can't wait for the results. Be careful biting bullets, they can really damage the enamel on your teeth ;D.

[Robin]

I wired my new solar panels together and then wired the array to the meter/regulator. The array clips easily onto (& off of) the regulator, and the regulator clips onto the battery with monster alligator clips on the posts. When the panels are hooked up, I run the cable out through the hole that my power cord uses so I can close the battery compartment.

The regulator is less than 12" from the battery, and the cable to the panels is about 20 feet long.

I haven't devised a stand for the array yet. I'm still figuring that one out. :-\

I'm all set with the Olympian Wave heater we bought. I had a new regulator put on my extra 20-gal. propane tank, as well as a 12-foot hose.

We leave this Friday for a 17-day trip to southern Utah and New Mexico. Although most of the time we will be hooked-up, we plan on spending a few nights unplugged in the desert. Two of those nights will be at Chaco Canyon in N.M. - the winter desert sky will be spectacular - layers of stars. The dwellings in Chaco were constructed along astronomical lines; doorways and windows line up with sun and moon rises and bright stars.

I will try real hard to avoid snow. The campground people in Santa Fe and Taos told us not to worry. What me worry? 8)

Happy Thanksgiving to all.

[RockyMtnRay]

Excellent! Sounds like you've got a real good handle on all this. One recommendation (you may have already done this): make sure there's a fuse (20 amps should do it) between the battery and the regulator. If you should happen to brush the clips together while hooking/unhooking this will prevent massive amounts of current from burning out your wiring or your solar regulator. A battery contains an enormous amount of energy. The panels themselves are pretty durable, electrically speaking, and can withstand both a direct short or being hooked up backwards to the battery. The regulator usually isn't as durable.

Have fun in the desert...I envy your trip into Chaco.

The folks in Santa Fe and Taos are probably telling the truth...while the Sangre de Christo mountains just to the east of those two burgs will likely be getting snow at times, the valleys should remain basically snow free until well into December (and at most have a light dusting of snow. Both are very nice towns with an excellent art scene...and won't be overrun with tourists at this time of the year. And, of course, the Taos Pueblo is a must see.

[Robin]

We returned from our 17 day trip through New Mexico this Monday night. We had a satisfiying vacation and cannot wait to go back again.

The weather was dry, no snow or rain - but cold! While hooked up, we ran the electric heater at all times, and the furnace for about 15 minutes every hour or so. Our first foray of winter RVing showed us the various drafts and air leakages in our TM. We brought it to the dealer to make it more airtight - for example, weather stripping around the a/c. Next time, we will bring a bigger electric heater.

Our two nights of dry camping at Chaco Canyon in N.M. worked well because our new solar panels allowed us to run the furnace almost constantly. The Olympia Wave catalytic heater was almost useless, and we will return it to Camping World.

Our big gripe is that the TM does not have a furnace vent in the back. The bathroom and bedroom were in another climate zone. A bigger electric heater will help, but not with dry camping. Utah, Taos, and Santa Fe, went down to the teens at night. Chaco Canyon was in the 20s during the day, and 7 degrees at night. I spent a lot of time with a really stupid looking, but warm hat on.

I'm real happy with our new solar setup. I have two 80-watt panels, each weighs 17 pounds. I still need to fashion some sort of rack for it. Any suggestions on material and design???

[Bill]

Robin -

You probably need a small 12-volt fan to circulate the warm air to the back. Of course that is another 12-volt load, but if you have enough juice to run the furnace, my guess is that a small fan won't hurt you.

Glad to know that the two 80-watt panels did a good job for you. I picked up my panels in Flagstaff last Friday (also two Kyocera 80-watt panels), but haven't had a chance to play with them yet. The guy who owns the shop (Northern Arizona Wind and Sun) had some commercial frames in stock, but he offered that they were kind of pricey ($65 each) and suggested that it would be easy to cobble up a couple mounting frames out of aluminum angle stock from Home Depot. When I get to doing it, I will post some drawings.

Incidentally, he said that with his truck-camper setup, he often just hangs his panels from tree branches with light ropes ... !

Bill

[Bill]

In December, I bought two 80-watt Kyocera solar panels from Wind-Sun in Flagstaff. They cost $634, plus a few bucks for a Morningstar charge controller. As noted in earlier posts, I am going to try portable mounting, rather than roof mounting. There are good arguments on both sides, but I figure if I change my mind, I can go from portable to roof-mount quite easily - but going the other way would be tougher. Anyway, I have just finished the first two solar-panel-related projects, both of which have been discussed in this thread.

First project: The panels are more rugged than I expected, but since I have been known to break bulldozer treads with a casually-dropped screwdriver, my first concern was to build some sort of padded carrying container for the panels - something that I could lay on the floor of the TM while travelling, and then carry outside easily when we reached the campsite.

The second project was to build some sort of tiltable frame for the panels. Solar-panel suppliers will sell you a nice heavy multi-adjustable tilt-frame for $65 per panel, but this seems way too expensive for such a simple function. Even the panel supplier agreed. I decided it was simpler to build a frame with two values of tilt - none, and 30 degrees.

The results appear in the photo below.

The tilt frame is two pairs of folding legs, made of 1" x 1" aluminum angle stock from Home Depot. The legs simply fold against the panel when not in use, or when no tilt is desired.

The carrying cases - one per panel - are simple five sided boxes. Masonite panels, glued and screwed over 3/4" x 3/4" hardwood corner blocks, and padded inside with 3" wide foam strips. The panel drops in from the edge, onto a padded bottom. You can see the edge of one of the panels in the box in the photo. Handles on each end of the box make carrying easy.

Doing these two projects, including design and buying the materials took about two days. It would have been faster if I owned a table saw, but that is unlikely to happen.

Next, the wiring! As Robin described, that's the easy part. Just a couple orange extension cords, and you're off and running.

Bill

[ccc6588]

Since TM can qualify as a 2nd home and the interest on financing is tax deductable, would the purchase of a solar electric panel qualify as a tax deduction as well for alternative energy and possibly as an addition to the asset?

[Bill]

ccc-

I tried to convince myself that the solar system would qualify for anything, including the solar energy rebate in Arizona or Maine! But I never got to a solid-feeling position, since both states have words like "primary residence" in their verbiage. Of course, I was concentrating on the renewable-energy rebates, not the second home deductions. My guess would be that IF you pre-qualify your TM as a second home, then extending the tax break to solar would be reasonably straightforward. But until you have done the first, I bet the second is an audit-magnet. But I am not a tax attorney or tax advisor.

There are web sites with some advice. It usually depends on what state you live in. Let us know if you figure out how and where to get some benefit, other than the basic up-front benefits that solar brings you.

Bill

[Bill]

Back in December, I bought two Kyocera 80-watt panels and a Morningstar charge controller. As Robin reported, wiring them was a breeze. Earlier this week, we got a chance to try them out for the first time, so I thought it might be worth a first-look status report to the group.

As an introduction, let me say that there are many good reasons to mount the panels permanently on the roof of the trailer, and only two arguments (that I can think of) in favor of keeping them portable. But those two arguments swayed me, and for the moment, at least, I chose to keep them portable. The first argument is that it is easier to protect portable panels from falling objects, such as hail, tree branches, and rocks kicked up by passing trucks. The panels are surprisingly rugged, though, so this argument doesn’t carry as much weight as it might seem at first.

The second argument is that the panels can be set up and moved separately from the trailer itself. This argument carried more weight with me, so I made up a couple of simple carrying cases, and we were off.

Like Rocky Mountain Ray, my wife and I really enjoy the National Forest Service campgrounds. The campgrounds are usually in beautiful spots, they are generally rustic, and the sites are large and well separated. They are usually “dry” campgrounds, meaning no hookups, and we are happy to give them up to get the sheer pleasure of being there. For this outing, we spent four days at Cave Spring campground in the Coconino National Forest, and it was no exception. The campground is alongside Oak Creek, and backed up against the wall of Oak Creek Canyon well north of Sedona, AZ. Each site seemed to be at least an acre, was level and well-drained, and had a concrete picnic table and a concrete fire ring. Drinking water was available at several central spigots, and there were several rest room facilities. It is also at 5500 feet, so we knew it would be cold at night. We would need to run the furnace frequently, and that’s hard on the battery. Solar to the rescue!

The NFS website describes the sites at Cave Spring as “Pull-through” and “No shade”. Both of these are wrong. Fortunately, I am reasonably adept at backing the TM, and the paved aprons were wide and well-angled, so no problem there. But every site is well-shaded. At this season, most of the trees are just in early bud, so what reached the ground was “dappled sunlight”. Now, dappled sunlight is wonderful to walk in, to camp in, to picnic in, and to take photographs in. But dappled sunlight is the kiss of death for solar power. One would expect that if 95% of a panel’s surface is in bright sun, then you would get 95% of the rated power out of the panel. Unfortunately, for various technical reasons, the opposite is true. If even 5% of a panel is shaded, then the panel generates less than 5% of rated power.

If my panels had been mounted on the roof of the TM, I would not have gotten any useful charge from them. Since they are portable, I was able to move them into a sunny spot, and get about 6 amps of charge rate. If there had been a large sunny area, I would have been all set. But the sunny spot was small, and moved with the sun, so I had to move the panels every 15 minutes or so. But we had better things to do than hang around the campground and move the panels, so we didn't get any useful charge.

Things I learned. Solar panels work great if you can set them up in FULL sun, and poorly in anything other than full sun. There is no middle ground. For someone who spends most of the time in open beach or desert campgrounds, or high altitude campgrounds with little shade (like Ray), this is not an issue. For someone like me, who camps a lot at wooded campgrounds, it is important to choose the campground and the individual site carefully, so as to get lots of sun on the panels.
Keeping the panels portable is a bit of a pain, but opens up some possibilities. Specifically, you can park the camper in the shade (important for keeping cool in the summer), and move the panels themselves into the sun.
In a solar-powered camper, it is important to have enough battery capacity to get through rainy/shady days. At the moment, I have only a single Group 27 battery, and we used it very carefully. In spite of that, the battery was pretty pooped by the fourth day. A second Group 27 battery would have made it all easy, and I am out to buy one today.
Though I don’t like ‘em much, a catalytic heater may be in our future.Bottom line – I am pleased with the setup, and the system will get a number of good workouts this summer. But a slight adjustment to the camping thought process is needed in order to get maximum benefit.

Bill

[B_and_D]

These are very interesting thoughts. Have been thinking about either solar or a very quiet generator.

We've thought about adding an extra battery to our truck that would be wired to charge while driving (away from the TM) and would be available to power the TM (back at camp). With our 1970 GMC, there was plenty of room in the engine compartment, but our new truck doesn't appear to have much room (at least from the top). We have a toolbox behind the cab that we take with us that could possibly house an extra battery, but ventilation would be questionable, maybe underneath the toolbox?

When we had this extra battery in our truck with cabover camper, we hardly ever ran out of power unless we just parked somewhere for days on end. We didn't have a heater, but it ran the lights and the toilet fine. There was an isolator that kept the main battery from becoming discharged.

Now you're making me think about maybe mounting the solar panel on the toolbox on the truck and connecting it to a battery underneath the toolbox. Perhaps we could wire it so that it got charge both from the alternator and the solar panel. It would be easier to park the truck in the sun when you leave the campsite than trying to park the TM in the sun given the constraints of the campsite parking.

??

[CC_Turtle]

I have been thinking about getting solar panels and keeping them portable - mostly for the same reasons as Bill stated. What about thief? do you think the panels would get stolen? or do you put them away when you leave your campsite??

teresa

[RockyMtnRay]

I have been thinking about getting solar panels and keeping them portable - mostly for the same reasons as Bill stated. What about thief? do you think the panels would get stolen? or do you put them away when you leave your campsite??

teresaYou can't really put them away, because you don't get any charge when they're put away. From my experience, the panels have to be in full sun for 4-6 hours with the sun pretty much directly overhead (i.e. from about 9-10 am to 2-3 pm) to get a decent recharge of your battery. Before 9 am or after about 3 pm, the angle of the sun is too low to produce much charging current. So, if you do as most folk do...leave the campsite for several hours during the middle of the day...you'd have your panels stowed away during most of the hours when recharging can happen.

Campground theft is apparently fairly rare or there'd be a heckuva lot fewer satellite dishes and generators left around folks' campsites. A suitable length of lightweight steel cable and a padlock should suffice to keep the casual, sticky finger type thief from walking away with a pricey solar panel. Nothing's going to stop a determined thief, though.

Bill

[Bill]

The responses to my first-look report tell me that I didn't make my point as clearly as I should have. Or maybe it was just too long!

First, Ray is exactly right. You need to have 4-6 hours of solid sun on the panels in the middle of the day. But if you have to continually move the panels to get it, then it is probably not worth having them. As I noted, I moved my panels a few times, just to prove that they worked, but then I quit moving them. We had better things to do than hang around the campground and move the panels. As a result, we got no meaningful charge into the battery, and our battery was pretty pooped.

In my opinion, the one big advantage of portable mounting of the panels is that if the situation warrants, you can park the TM in a place that will be shady all day (under a tree, for example), and set up the panels in a place that will be sunny all day. Portable panels can easily be plugged into a 50-foot extension cord, if that is what's needed reach the sunny area.

So before buying panels, and choosing how to mount them, think about how you usually camp.

o If your TM is usually in the sun most of the day, then permanent mounting on the TM roof is best. This will be the situation if you camp on the beach, in the desert, or at high altitude, since these places generally lack shade.
o If your TM will usually be in the shade, but there are large sunny areas in the campsite, then portable mounting may be best. This is the case if you camp in areas where there are a few big trees, but they are scattered.
o If you usually camp in the forest, where there are NO areas of all-day sun, then solar may not be the best solution for you.

And of course you may have to integrate all this with your personal feelings about generators. In many campgrounds, generators are discouraged or forbidden. In some, they are welcome. And if you are truly boondocking, there may be no rules other than your own.

HTH

Bill

[Caver]

I would like to thank RockyMtnRay for his detailed information on his solar panel installation and his excellent advice. It certainly made my installation go a lot easier.

I started planning this before our TM 3023 was being assembled. Engineering at TM was very helpful and the factory ran a Wiremold conduit along the side and a pair of 10 gauge wires from the area behind the shower base where the controller is located. That's the area I installed the solar charge controller. You can see the conduit in the two photos on the left. I could have done this... It's a lot easier when you see how someone else has run the wire and attached it to the torsion bar arm. I guess you could call this a solar ready option from the factory.

The TM engineer recommended mounting the panels on the rear shell. It gives them some protection with the higher front shell and keeps the drag down as well. I decided to mount the panels 1.5 inches above the roof to help keep them cool and still keep the profile low. 1.5 inches is important so I can reach the mounting hardware which consists of four 1/4x20x1/2 inch SS bolts for each panel. I ended up making a special fixture to help tighten the bolts. It's important to be able to service the panels.

The two 90 Watt Photowatt panels are installed with .063 inch thick aluminum brackets. These are attached to the roof with the Loctite 330 Depend adhesive. As Ray pointed out this is extreme overkill but overkill is good to keep your panels on the roof at 70 Mph.

I was able to get the local sheet metal shop to cut me two 7.5 x 48 inch strips of aluminum out of their scrap for $10. Since I have access to a metal sheer and bending brace, the 8 brackets only took an hour to fabricate and then another 30 minutes to drill the mounting holes.

The two panels, wire, brackets, and bolts weigh 40 lbs. I did have to adjust the torsion bars on the rear shell to compensate for this. I added 3/4 turn on the forward bars and 1/4 turn on the rear.

The slope of the panels is the same as the roof so I'll have to remember to wipe the panels off before I raise the rear shell.

So far the panels have kept the two series 24 Marine batteries fully charged in the driveway. No need to plug into house power.

Ray

[RockyMtnRay]

Wow! Nice job! Glad to know I was able to be of help. :D

[efelker]

Caver/Ray:

Wow -- you guys are my heros. Already making the shopping list.

Ed

[RockyMtnRay]

Caver/Ray:

Wow -- you guys are my heros. Already making the shopping list.

Ed
**blushes** Glad to have started a possible trend here. Actually, Ed, you kinda inspired this many, many moons ago when you said I was the type who took the road less traveled. Well, that sort of put me into a pioneer's and explorer's mindset while I was traveling those seldomly beaten paths. And one aspect of an explorer's mindset is to report back about what can be done and what seems to work. Caver has capitalized on my exploration reports and come up with a much more sophisticated and better system.

[Cowboy Cody]

I am curious. I have a truck that has a 110 volt AC outlet in the bed. If keeping the battery charged is a problem? Would hooking a small 6 amp charger directly to the TM battery help my alternator keep the TM battery charged with the fridge running going down the road?
Thanks,
Cowboy Cody

[Bill & Lisa]

Electricity is not one of my strongest points :eek: but if I follow the flow path the choice is:

1. TV alternator produces DC to charge TV battery and flow through Bargman connector to handle refridgerator DC load and charge TM battery.

2. TV Alternator produces DC some of which is routed to an inverter and converted to AC to power the 110v outlet. A portable DC converter is then pluged into the outlet to change the AC into DC and supplied to the TM battery.

path 2 will have loses due to less than 100% efficiency in the conversion process (x2).

Also, not sure how you would prevent path 1 from still being present if you chose to use path 2. You still need to plug in the Bargman to control the brakes and stop lights, turn signals etc. You could end up with 2 charging paths somewhat independant but interelated. Due to the drop in path 2 all flow may be through path 1 and even reverse flow path 2. Here is where my electrical knowledge weakness begins to display itself.

Bottom line in MHO, path 2 is less effective than path one and could even represent a serious safety hazard. Don't do it!

Bill

[Freedom]

Actually, an alternator produces alternating current which is then "rectified" into direct current. (That's why they're called "alternators".)This rectification is done by a series of diodes which sort of turn the bottom half of the electrical wave over and it comes out as direct current although it isn't actually. (It's a modified sine wave which simulates direct current) At one point there were people who were tapping into the alternator before the diodes and pulling alternating current from it for running tools or charging tool batteries. You would have to check the wiring to the outlet in the bed to see if it runs through an inverter or if it was one of the alternating current outlets directly from the alternator. I also remember that the alternators were not holding up very well when the alternating current was drawn from them. Some production cars drew alternating current directly from the alternator to run through the rear window defroster as it produces more heat than the direct current. I'm not sure if any manufacturer is still doing that or not.

[Joe]

Theoretically, Jim is right. However, even if the alternator output is AC, what is the voltage, and more important, what is the output power capacity of the alternator. But before we get to deep in this, we need to know where that 110VAC outlet in Cowboy Cody's truck is getting it's power from.

[Cowboy Cody]

Joe, the power outlet is designed for use as a power supply for electric appliances. The power outlet must only be used after the engine is started. While the vehicle is being driven the maximum capacity is 115 VAC/ 100W.

While the vehicle is stationary and in park or neutral 115 VAC / 400 W. The outlet is a factory installed on my 2005 Toyota Tacoma Toyota equipped with towing package that has the larger battery. I don' know if this helps conclude if I can add a small 6 amp battery charge to the TM battery while in tow (With the refrigerator running) ?
Cowboy Cody

[Joe]

Well, in that case you might be able to do it but it will be tricky. First you will have to remember to never connect the battery charger until the engine is running. Then if you stop for lunch or to gas up, you'll have to remember to unplug it and then reconnect it when the engine is running again. Then, to Bill's point there is the problem of keeping the 2 circuits separated. You could do that with a battery isolator. But my Dometic refrigerator draws 10 amps @ 12VDC, so your 6 amp battery charger still won't supply all the power it needs. And I don't know if trying to draw 10 amps from a 6 amp source will kill it completely or if it will just not work very good. My opinion is that this is too much trouble and too uncertain to try.
My 1998 2720SL came with a 6300 inverter. After about a year I replaced it with a 7300 which has greater capacity and 2 stage charging. We leave our TM set up in the back yard year round and connected to the 120VAC house power so the battery is almost always fully charged. I have a 60-0-60 ammeter in the battery circuit so I can check on the charge or discharge of the battery. On a trip I have the refrigerator on 12VDC and I leave the trailer plugged into the TV all the time unless I plan to leave the TV for a couple of hours. At the end of the day when we connect to the campground power, I usually check the ammeter. It almost always shows the battery charging at about 25 amps. That tells me the TV will not supply enough power for the refrig while traveling. But we have no problem with the refrig temp because we freeze everything we can before we leave and we pack it as full as we can without blocking the air circulation from the fan. when you open the door of a nearly empty refrig all the cold air falls out onto the floor, but if the refrig is full there is very little air to fall out.
This has gone far astray from the Solar Panel subject so I'll stop.

[Cowboy Cody]

Joe, thank you for your well thought out answer ! I have been starting up the fridge the night before and think freezing the food and keeping the fridge full is the way to go. I have read stories of the battery becoming low while traveling so I thought the charger may be an easy fix. It does not sound like the hook up is worth the trouble.
Regards,
Cowboy Cody