Solar or Generator??

[Ramblin_Recks]

We are going to have some short boon-docking trips (3-4 days). I do not know my actual energy needs right now, but the DW and I are conservative when it comes to water and power. I really just want to get the biggest return on my $1400.00 budget for this project.

So initially I plan to get 2 T-145s, Trimetric monitor, and then I get bogged down solar or generator…

If it is a generator, I’m leaning towards a Honda EU2000i, or a Yamaha EF2400SHC and a new converter/charger (like maybe PowerMax PM4B Boondocker).

I’m thinking the generator is more versatile and could be used for other tasks than charging the batteries. I know I need to carry gasoline, but that’s ok.

If its solar, I’m thinking this system is “set-it and forget-it”, once it is installed making it easy to keep the batteries charged… but only to charge batteries. I think I would need to buy 4 T-145s (or 105) for solar. Then I start

thinking about my pin weight, I have not got mine weighed yet , but 4 batteries would be about 250-300 lbs., and we added the W/D Stack in the front closet. My BFT can handle it, but I like to keep the “weight police” at bay ;).

Solar or Generator??

Thanks for your thoughts.

[JiminDenver]

I know that PT gets more out of his 256w in shade or cloud than I do with my 230w poly. My 230w poly gets more than my 220w mono, it can't even wake up the controller in cloud cover that the poly can pull 4-5a.

Part of a balanced system is also knowing your needs and what conditions you will be in. In my case we had 2 days of total sun, 3 days of total cloud cover and the rest were early sun and clouds by noon. So poly is the best mix of the two extremes. 16a in good sun and at least enough in the clouds to get back to float.

Remember that if you have enough power for the low light times, you will always be happy. Only have power while the sun shines and eventually you will say hello to my little friend, mister generator.

[pnichols]

JiminDenver wrote:
I'd be looking for some Uni-solar rolls. Last time I checked, 65w was $100 or so.

Thanks for jogging my memory on Uni-Solar.

This Aussie link for them shows powers for their flex panels only going up to 32 watts:

http://www.unisolar.com.au/index.html

Do you have a better link for Uni-Solar ... perhaps an American distributor?

Thanks in advance.

[Snowman9000]

Re the amorphous panels, BFL asked a great question, and I never saw it answered. As far as performance in the shade, if you calculate watts per square meter, are they really any better than mono or poly?

[Snowman9000]

The Solar Blvd 100w kit for $165 is almost exactly the same as what I built from another source. Mine is 23"x26"x 3" thick, and IIRC they list theirs at 3.5" thick. Theirs has folding legs which I have not yet added to mine. Theirs includes a questionable controller, but you can get a decent one on ebay to replace it, for ~$15. Or just bypass the controller if you keep an eye on the charging voltage. To me, it's not that hard to store or deploy this small package. I have a cable and padlock for it, but if someone does steal it, I'm out $150 give or take. Say $200 if they get everything. Same thoughts as to if it happens to get damaged.

If I had the Solar Blvd kit, I'd put the controller on the end of my cables, near the battery, anyway. Instead of on the panels.

[JiminDenver]

pnichols wrote:
For portable solar to always keep the panels in the sun regardless of where the RV is parked and to keep holes out of the roof - instead of regular rigid glass panels merely on hinged frames - here's examples of what I have in mind -> 2, 3, or 4 of these that can be rolled up for storage:

http://www.powerfilmsolar.com/products/?r60&show=product&productID=276215&productCategoryIDs=6578,65...

or 1 or 2 of these:

http://www.powerfilmsolar.com/products/?fm165400&show=product&productID=271512&productCategoryIDs=65...

I'd be looking for some Uni-solar rolls. Last time I checked, 65w was $100 or so.

[Almot]

Ramblin Recks wrote:
I hadn't given a portable solar kit much thought, I will research.

Don't. Pianotuna is right - this is a niche that works for only a few. I would understand portable when panels were expensive, but not now that they are cheap.

Don is also right that you can have enough panels to work in the shade, though don't count on much. Check amorphous panels, though - rigid and flexible. I did, and come to conclusion that unless for very specific reasons like very expensive motorhome that you just can't bring yourself to drilling any holes in, and therefor have to go for glue-on flexible strips, or if you are camping in the shade often and for long periods of time - I don't think amorphous flexible is the way to go. Another reason to consider amorphous flexible would be - if 2 long narrow strips fit your roof better than 2 or 3 rectangular crystalline panels.

Amorphous rigid - not sure either. Don says they work better in low light, must be true. But they are less efficient in full light. For a mere few days of boondocking I wouldn't set such a specific goal as shade-efficient panels. Forget about that photo by BFL13 titled "Good luck with any solar here". He probably stayed there 1 or 2 days, and scared the heck out of you all 🙂 ... With 4 *6V batts you could stay 4-5 days in the darkest forest with low overcast, if you wanted to. Probably even BFL could, despite his dislike of the term "energy conservation". I would be able to stay there with 4*GC for 7-8 days, with lights, furnace and some laptop use. Energy use per person varies a lot - depending mostly on a particular person, so you should know where you are on this scale.

[pianotuna]

Hi Phil,

They make the Efoy fuel cell look like a bargain. $895 for 60 watts of rollable panel?

[pnichols]

For portable solar to always keep the panels in the sun regardless of where the RV is parked and to keep holes out of the roof - instead of regular rigid glass panels merely on hinged frames - here's examples of what I have in mind -> 2, 3, or 4 of these that can be rolled up for storage:

http://www.powerfilmsolar.com/products/?r60&show=product&productID=276215&productCategoryIDs=6578,65...

or 1 or 2 of these:

http://www.powerfilmsolar.com/products/?fm165400&show=product&productID=271512&productCategoryIDs=65...

[JiminDenver]

Eventually I'll mount my solar but it may not be these panels. Using these portable will give me the best idea of what fills our needs without a lot of investment.

Mounted vs portable? 6 in one hand, half a dozen in the other.

Portable is cheaper as it doesn't need to be mounted and it takes half as much to fill your needs tracking the sun all day. This can mean more on those days that your chance to catch some rays is early or late and cloudy days. Trade up your rig, no worries, just take the kit with you.

The pain with it is storing it, worrying about it and the fact that it doesn't charge on the road or in storage.

Mounted panels are always up there and doing their job. You can tilt them for better exposure but most are flat and hands off. There is also much less chance of them walking off.

The downsides include having to buy twice as much panel as well as a more expensive controller to handle them. They have to be mounted and that cost if you don't do it yourself. Sell the rig and the panels are likely to go with it.

So far the 230w's met our needs with ease, even left flat for a week. I'm not ready to call it good because our needs have grown considerably since getting it. It takes a while to get use to using these new fangled toys when you are use to a tent. I don't want to be remounting or adding panel later.

[pianotuna]

Hi,

The folks who do portable solar are in the vast minority. With panels being so cheap it is usually easy to add enough to have adequate charging, even in the shade.

[Snowman9000]

Since fivers don't usually charge well when towed, I would think that even if you do something portable, you would benefit from something permanent on the roof as well.

[Ramblin_Recks]

JiminDenver wrote:
My basic system is a 230w panel ($50 on CL) a set of solar cords ($32 on ebay) and a $100 Eco-worthy MPPT controller. It can put out up to 16a for most of the day if the need and sun is there.

This year we will also have the second $50 panel along with it's own cords and controller for use on the inverter bank or combined on which ever bank needs that kind of power.

The nicest thing is even though we use the furnace, lights, fans, TV/DVD all day long, our battery is fully charged at nightfall. That's because the basic system can pick up loads as high as 16a while the battery stays in float. Over night with temps in the 20's our grp 27 drops all the way down to 12.57v.

Even with new panels the either system would be $400. You can get a 200w PWM kit for $300 shipped.

I hadn't given a portable solar kit much thought, I will research. Thanks for the info.

[Almot]

pnichols wrote:
Apparently #1 you have some way around drycamping for a week or more in conditions like BFL13 shows in his "Good luck with any solar here" photo

There is no way around drycamping for a week in that - rather rare - situation shown on that photo. If you read my previous post again, this was what I said - when it's dark and rainy and you can't carry enough panels and batteries for bad weather, then solar is out of question.

pnichols wrote:
I hope it's not the usual "I have battery capacity XX big enough to get by ... or my panels put out XX amps per hour even under grey skies ..." kind of arguments.

I hope you will eventually look into what Don wrote (in another thread?) about amorphous panels and low-light conditions. Plus, energy conservation. Grey skies is not a problem - at least, I don't find it to be a problem for 4-5 days with 490W flat solar and 300 AH bank. For +5 days I would need more panel and/or more battery. Grey skies AND dense trees canopy AND camping more than 5 days would be a problem.

pnichols wrote:
First off, you're not supposed to "walk" on RV roofs

Who cares about what is "supposed"... I walk, stepping on rafters. People over 200 lbs probably shouldn't be on the roof. Yes, it's safer on hands and knees. Waxing a roof is akin to snake oil. 303 Aerospace makes sense perhaps. Though new or wet roof can be slippery enough without any treatment.

pnichols wrote:
Sleeping bag in an $$$ RV ... ridiculous

...and sleeping bag in $$$$$$ condo during blackout is not ridiculous? 🙂
The bag was mentioned in a context of camping without big solar (not my case), AND in a bad weather AND if there is no desire to buy and run a genny for such conditions. Many people prefer going to sleep early - in a bag if needed - than having to listen to generator. I'm personally trying to avoid such tough choices, prefer sunnier locations. If adverse camping conditions are frequent, and nights are cold not by 5 am but by 7 pm already, and you need to be out there for more than 3-4 days, then it's difficult, yes.

pnichols wrote:
I read books, watch movies, ... in complete 72 degree comfort and top up the AGM batteries accordingly about every 3rd day with the little genny

Same. Only top up my AGM batts on the average 4 days out of 5, and without a little genny. Wouldn't want to be out there in +90 heat without A/C though. No more than a day or two. Would rather find a place with hookups then - it would be cheaper and quieter.

[JiminDenver]

My basic system is a 230w panel ($50 on CL) a set of solar cords ($32 on ebay) and a $100 Eco-worthy MPPT controller. It can put out up to 16a for most of the day if the need and sun is there.

This year we will also have the second $50 panel along with it's own cords and controller for use on the inverter bank or combined on which ever bank needs that kind of power.

The nicest thing is even though we use the furnace, lights, fans, TV/DVD all day long, our battery is fully charged at nightfall. That's because the basic system can pick up loads as high as 16a while the battery stays in float. Over night with temps in the 20's our grp 27 drops all the way down to 12.57v.

Even with new panels the either system would be $400. You can get a 200w PWM kit for $300 shipped.

[Ramblin_Recks]

JiminDenver wrote:


That's why my system is portable. I'm never on my roof and I can follow the sun for peak amps all day, even if the rig is in the shade. Both panels can do up to 30 amps all day with sun and 7 amps in the clouds.

Jimin-- What kind of portable solar system do you have?
Thx