Green Dreams

[pfisher]

I am new to this forum so I apologize if this question is not in the right spot.... We just purchased a 1976 31 sovereign land yacht. My husband is a custom builder and we want to redo our airstream trailer and make it as "green" and energy efficient as we can.. Does anyone know if there are any protocols (my husband is a certified green builder)? We would like to use this trailer to help showcase his Eco/green philosophy as well as have a great time traveling with our two young boys. We would like to model our airstream on the Airstream that Kevin Fitzsimons did a few years back.

Thank you for your help!
Pam

[streamhead]

unless you are willing to spend 20,000.00, forget about solar/battery combo's. even 5000 will just get you a couple of extra days over the stock batteries. I am a solar expert, and people always forget that solar panels will work for 30 years or more. So even though a single module puts out only 200 watts, it will produce 1 kWh per day for 10,000 days which is 10,000kwh which is worth about $1700 when a panel only costs $800. Now what is expensive?

[Dave Park]

pfisher - I think your post deserves a thread of its own!

[pfisher]

Need some help......

We are in the process of putting together our plan for our remodel. Since the expenses will be significant I want to prewire for Solar and add it later...

My question..... What type of wire and where do I run it to??

Thank You!!!

Pam

[CanoeStream]

Hi Pam -- I have green aspirations and a long pedigree in that direction. But I believe that solar panels have amp-hour production that best helps a stored Airstream keep batteries topped off. During active camping, solar panels might cover a moderate amount of water pump output, fridge monitoring while chilling on LP gas, minimal interior lighting and that sort. Furnace fan operation is at the higher end of what is possible -- but entirely reasonable under careful management. This presumes a prolonged trip, fair exposure to the open sky and somewhat sunny conditions. The price of operating on solar-only is high considering such unreliable, intermittent or partial conditions.

Inverter conversion to 120 volt alternating current is extraordinarily inefficient -- and worthwhile only for specially designed television equipment. I've never had a reason to watch TV while camping. Apologies to those so dependant...

The above presumes a desire not to carry 4, 6 or 8 Group 24 (or Group 27) batteries -- golf cart or not. Just my preference. Simpler is gooder....

That being said -- my practical experience has been that 95% of the time I am not in a commercial campground, 80% of the time I am not boondocking and we are hooked up to 120 volt power (State Parks and the like). All of which argues against solar working for our circumstances. Solar certainly could work for frugal boondockers in more southerly, tree-free zones. All experiences differ. What are yours?

[FLYNCLD]

Hi pfisher!

You might want to take a look at our website. There is a fair amount of info there on this subject. There is also a few other threads that you should check out. I will post a link to them as soon as I find them!

The Flying Cloud Eco-Discovery Tour

Flyncld

[Wabbiteer]

Inverter conversion to 120 volt alternating current is extraordinarily inefficient

Let's frame that statement with a qualifier - that solar electricity conversion is inefficient.

Imagine a square meter surface area facing the sun may see 700 to 1000 watts energy during each of the 5 peak sun-hours each day.

If you are collecting that as heat transferred into water, a collector may see over 70% efficiency in harvesting the sunlight, and the complete system may hold up to 30 or 35% efficiency... or, a square meter of panel may harvest 350 watts of usable heat energy per hour.

If you are collecting that sunlight as electricity the PV collectors may see 12-18% conversion and the losses from batteries, wiring and inverter (not counting the ultimate load) drop that to 7 to 11%. So a square meter of PV collector may harvest 70 to 110 watts of usable electric energy per hour.

Now factor in clouds - days long weather events - and all the hassles of locating the panels for optimum performance - and our $$$ investments efficiency drops yet again. See Surface meteorology and Solar Energy for your local site data.

The greatest gain anyone can see is through conservation - limiting the need in the first place - which is really what building 'green' is all about...

[pfisher]

Thanks all for the posts....

Since are new to this and have two boys 8 & 10... We won't be fulltimimg any time soon ( too many football practices) to go....

I think the majority of our time will be spent in state parks etc.... Some boondocking but not the norm...So that being said I think our solar needs would be to keep e battery topped off and gps tracker juiced.... If you have any other insight please let me know.. Thanks for your help!!

[SpaceEgg]

I think you would need a tiny little solar panel to keep a deep-cycle battery topped off. Especially if all you are using the battery for is 12v lights, a GPS tracker, and a water pump (for instance, a $60 15w panel for a trickle charge). Beats the snot out of buying and transporting a generator and more gasoline.

To alleviate the dilemma of parking under trees, I put my solar panel on an art easel tripod with approx 30' wire. Chances are I'll have some sunlight within 30' of the trailer.

I would recommend anything in the realm of 12 gage wiring for the solar so your wire is durable and you lose as little electricity as possible. Added bonus would be to get an additional jacket put on the electrical wiring's coating - rodents like to infest dormant trailers, and they LOOOVE to chew on plastic.

[SpaceEgg]

I posted this info earlier, but here it is again, in case you are thinking of configuring enough solar to power batteries to power an AC system.

FORMULA:
Total the amps on your batteries and divide by 12. Take that number and set it aside, we'll get back to it in a moment.
Total the amps on the devices you will use on the inverter, add another 1/2 amp for the inverter itself.
Take THAT total and divide into the first number you came up with.
The result will be your runtime in hours. The more batteries you put in parallel the longer runtime you can expect.

from Inverter FAQ

also Frequently Asked Questions (FAQ) - DC Battery Specialists

happy green trails! Post photos along the way!