Question about Solar ....

This is how we look when camping off the power grid... When we need to run a fan around the picnic table to keep the mosquitoes away we just run a drop cord and plug in a fan haha... This is off the power grid sitting in Wichita Mountains WildLife Refuge in Medicine Park, OKLA. I am running my 255AHs battery bank and being able to re-charge my batteries to 90% state of charge every morning at 8AM running my 2KW Honda generator for three hours using smart-mode charging technology.

If I had a good solid 8 hours of solar panel recharge time on the batteries it is possible I could get away without running the generator at all. I have space on my POPUP roof for two panels next to each other on one end and two smaller panels running on both sides of the air conditioner. For PLAN Bs however I would never do this without having the generator available for use. For us its all about PLAN Bs...



Roy Ken

I am thinking you might be thinking different about how to use the solar panels. Running things directly from the solar panels will require alot of panels. The direction of the sun doesnt always give you a constant power output of the panels and of course when the sun goes down you are dead in the water.

What most folks do is have a couple or more of batteries installed like the GC2 6v Batteries in series to give you 12VDC at around 220AHs of capacity. The more the better. Then you will use a small 300Watt to 600Watt PURE SINE wave Inverter to produce the 120VAC to operate your small appliances like the HDTV, DVDs, etc in addition to some other small 12VDC items directly from the battery. Most camping off the power grid gets by pretty good with 220AHs of battery capacity.

Now that you have enough battery power to run all those small appliances and direct connected 12VDC items you want to run you will need a way to re-charge your batteries everyday so you can do all of this all over again the next day/night battery run.

Most folks will re-charge their batteries in the mornings when allowed to run their small 2KW Honda type generator. This is done by connecting your trailer shore power cable directly to the generator 120VAC receptacle using a RV30A-15A long adapter. Using smart-mode charging technology you can re-charge your batteries to 90% harge state in as little as three hours of generator run time. The solar panels really come into play big time re-charging your batteries during the daylight hours when the sun is out. Between the two re-charge sources you should have at least 90% battery state of charge to be able to do the day/night run off the batteries using all your 120VAC/12VDC toys you want to use.

I don't have the solar panels yet but they would be a big asset in keeping my batteries re-charged.

I don't think I would be very successful camping off the power grid with just solar panels. It looks like about 120WATTS of solar is all I would be able to mount on my POPUP trailer anyway. By having the larger battery bank (mine is 255AHs capacity) and being able to run my 2KW generator at 8AM during the morning breakfast meal and then having the solar panels going during the daytime hours would really give me a good solid 90% state of charge on my battery bank. This should allow me to do all these things up to lights out around 10-11PM at night and still run all the necessary trailer keep alive things until 8AM the next morning where I can re-charge my batteries and do it all over again for the next day/night battery run.... This is my camping off the power grid game plan...

There is many ways to camp off the power grid I guess but this method works great for us supporting all of the home entertainment items and my other power Hungary hobby of Amateur Radio operations....

Roy Ken

Hey guys... thanks for all the information. I dont really think i need the microwave. i need to look into some of those low wattage camping ovens.... and i like cooking outside anyway.

one question though.... can solar run a small fridge ? i really dont like propane. it makes me very nervous to deal with gas. i know alot of people use it but i worry about explosions.

is there such a thing as kind of cold box that not quite a fridge but can be plugged in to keep a few things cold... like some eggs and milk ?

its not something i have to have when i am not on shore power but...i was just kind of wondering because i am not up on all the products out there.

thanks

100w 12v 5a panel $125

6a controller $40

This will be a good start especially if you can aim at the sun. But I think you may need to pass on the microwave as it will take more battery, large inverter, and more solar to recharge.

With any off-grid desires, I would caution against microwave use if yore not going to )A have a large capacity battery and/or B) have a generator as a backup.

A microwave is just right behind an air conditioner as far as typical RV appliances for power consumption. Of course it is used sparingly but I would suggest other methods of heating if possible while off grid.

At least make it a small wattage MW. My built-in MW is 1500 watts and even pushes my generator around. I'm seriously considering swapping it out for a lesser wattage unit. But I digress.

I would suggest a dual battery bank. Several folks on here have dual and even have had quad battery banks for ham radio and the like (c'mon RoyB, where are you?).

Pianotuna has been doing solar and off grid for quite some time so I'd really look through some of his other posts.

You could sling some panels on the roof of your A frame but the angle might be less than desirous but that can easily be overcome but putting something more elegant than a rolled up towel under the low side to place the panels as perpendicular to the sun as possible.

You're also going to need an inverter as those are not included. Something in the 1500-2000 watt range based on what describe above. If you drop microwave usage, then possibly 1,000 watts or less would be more than enough. I have a 400 that would do it if the TV is LCD or similarly low power.

You will need to do the math on what you will consume in a day, both 12v and the impact of any 120v drains on the battery. If you can't make it one day without draining the battery below 50% (about 12.1 volts iirc) then you need a second battery (and in my opinion...quit using so many electronics ;) ).

Then you'll need to figure out how much solar you need to put that daily usage drain back into the battery(ies). Then, there's always the real world tests, which I would do at home before you hit the road. Field testing can be the field in your driveway.

Hi,

Solar has never been cheaper. This winter prices at some places dropped low as 0.62 cents per watt.

Here is a simple flow chart:

budget-->energy audit-->battery storage-->size of solar system.

It is best to "aim" at between 60 and 150 watts of panels for every 100 amp-hours of battery storage.

Try these sites:

http://rvroadtrip.us/library/12v_system.php

http://rvroadtrip.us/library/solar_install.php