How to mount Solar Panel to roof of CT?

[bdosborn]

Now, getting a bit more technical: the simple controller I linked above only has connections for "Panel" and "Battery", where most controllers also have a "load" connection as well. What this is for is to connect to a fusebox (suggested) then to the devices that you want to run. (except for high-drain devices, like a big inverter - you would just connect the big inverter directly to the battery) The reason is that the 'Load' connection also regulates the voltage going to your devices to keep it steady, whereas the cheap one above will be outputting up to 14.5 volts when the sun is out.

No, that's not quite right. The voltage at the load controller is the same as the output of the solar controller to the battery, which will vary up to 14.4 V for a Sunsaver on a flooded battery. The load controller is used to disconnect the load from the battery at a preset voltage (11.5 volts for a Sunsaver) so you don't accidentally drain the battery too much and ruin it. The load disconnect typically has the same current rating as the controller so its usually too small for an RV. 6 to 10 amps is also pretty small for a teardrop. Gee, can you tell I kind of like Sunsaver controllers?

Bruce

[bdosborn]

There is actually a third option in controllers, but you only realize the advanges of them if the panels are stationary. These are MPPT controllers, or Maximum Power Point Tracking. These are pretty pricy, and do not really have a use in our circumstances, but if you were installing for a cabin or home, it would be a worthwhile investment.

Well, not to be nitpick, but...

I'm not sure what stationary panels has to do with MPPT. I have an MPPT controller on the Boxcar, which is NOT stationary and it works just fine. The manufacturers say you can expect between 10-30% increase in solar harvest by using an MPPT controller (depends on the ambient temperature) and my experience is that its closer to 10% than 30%. They're so expensive it's usually more cost effective on a small system to just buy more PV panel. However, there is one situation where MPPT makes sense; when your roof is full and there's no more room for panels. You can use MPPT to wring every last bit of power from your panels. MPPT also appeals to gadget freaks who just can't live without them (like me)

Bruce

[subterran]

Please do not buy anything I suggested in this thread until you have investigated the products thoroughly and know that they will do the job you need them to do.

bdosborn has much more practical experience than me. I would definately take his advice over mine, since I have not yet even been able to mount my system (!), let alone get it to produce power.

I do wish anyone seeking to learn more about alternative energy, and implementing available technologies to live more efficiently the best of luck and gods speed!

[bdosborn]

I have not yet even been able to mount my system (!), let alone get it to produce power.

Don't worry, you'll get that system installed and working. Just keep posting so we can watch your progress. I don't ever post my flops, just the stuff that works so people don't make the same mistakes I do. Seems like I have to do everything twice....

Bruce

[Steve_Cox]

I have not yet even been able to mount my system (!), let alone get it to produce power.

Don't worry, you'll get that system installed and working. Just keep posting so we can watch your progress. I don't ever post my flops, just the stuff that works so people don't make the same mistakes I do. Seems like I have to do everything twice....

Bruce

Bruce,

Your secret is finally out. I find the flops usually cost just as much or more than the successes. I'm always fascinated with the posts on solar, and go off the grid vicariously through others efforts.

[bdosborn]

I find the flops usually cost just as much or more than the successes.

Yup, that's why I refuse to keep track of my build costs. I'd have to show two columns - Stuff that worked, Stuff that flopped. I don't want to know which number is bigger.

Bruce

[Quarterbore]

My plan for a Solar setup is to buy one of those steel wagons and then mount the batteries, solar panel(s), and solar charger all to wagon. My thought is, I can secure everything to the wagon via mounts and then chain the wagon out in the sun as mentioned including the option to move it easily as the sun changes.

This way, if I ever wanted to use the solar setup around home or anywhere else, I can just pull the portable power system to where I need it and run an AC extension cord from the battery pack/solare panels.

The other part of my goal is to have a roof rack added to my cargo trailer and the mount I make to attach this to the wagon will be spaced exactly the same width as I will have my roof racks spaced so if I ever wanted to mount the panels on the roof of the cargo trailer I would simply mount them to the ladder racks. I am going with a 3-row rack so I can move the middle to adjust for that length.

I have not bought the solar panels yet as I just have not decided what I should buy. I figure I want about 200 to 400 watts from the solar panels total and my plan was to get two solar panels to give me that output. Later I might add more but my primary convcern is to be able to run 12v fans and short lengths of 12v LED Rope light at night to illuminate the trailer.

Lots of good options, just trying to decide is the investment worh it or shoudl I just buy a Honda EU2000i!

[jwhite]

I have a honda E2000 and I love it,I bought a extended run tank off ebay and I ran it 2/days straight this weekend on 5 gallons of gas.
you can also refill the tank while it's running so you dan't have to shut it down to refuel.
I am considering buying another one but they are around a 1000.00 and you can find new and used ones on ebay all the time.
I found out that I can't run my AC and the golf cart charger at the same time not a problem but in the summer I need to be able to do both.
I am wondering if I should just buy a used generator off of craigs list for a couple hundred dollars or they have them at lowes new for a little more.
and just use that to charge the golf cart which should only take a few hours depending on how low the batteries are and use the honda for everything else.
My buddy had a regular generator and he had to refill it every 6 hours.
and it was loud.
I am also looking into the solar power just to keep the batteries for my lights and stereo charged up.

[lonerider]

Get one of these
http://www.amazon.com/dp/B000C1Z2VE/ref ... B000C1Z2VE

[bdosborn]

Here's an 85 watt panel at $1.85/watt . This is a great price. Cheaper than a LOUD generator and will keep up with your energy use (get 2 if you use a lot of power like I do).

A 135 watt solar panel is about as big you can ship economically.

Bruce

[astrotrailer]

I recently added a 3rd 80 watt panel and upgraded from a PWM controller to a Sunsaver MPPT controller. I rewired the panels into a series so the output is about 51 volts under full sun. The MPPT controller drops the voltage to the required charging voltage and ups the amperage to maintain the wattage. I am getting a nice increase in total watts actually going to charge the battery. I now have used up all the roof space so I think I am done adding capacity.

I found last summer when I brought along my wife with her 2nd laptop we were drawing a bit more juice so I wanted to add more watts. We are also running a 12 volt personal swamp cooler and DC fridge. I am also using the battery power all night to run the astronomy mount and laptop when imaging the stars. There is no way I could go 4 nights in a row at the Golden State Star Party without the solar solution. I don't consider running a generator an acceptable option. I don't want to fool with the gas or the noise.

I am thinking about some ways to put the solar to use when I am at home. I am thinking about buying a couple more large batteries to create a ups solution to provide to keep my home network up and provide a bit of DC lighting in the house when the power goes out.

[astrotrailer]

I recently added a 3rd 80 watt panel and upgraded from a PWM controller to a Sunsaver MPPT controller. I rewired the panels into a series so the output is about 51 volts under full sun. The MPPT controller drops the voltage to the required charging voltage and ups the amperage to maintain the wattage. I am getting a nice increase in total watts actually going to charge the battery. I now have used up all the roof space so I think I am done adding capacity.

I found last summer when I brought along my wife with her 2nd laptop we were drawing a bit more juice so I wanted to add more watts. We are also running a 12 volt personal swamp cooler and DC fridge. I am also using the battery power all night to run the astronomy mount and laptop when imaging the stars. There is no way I could go 4 nights in a row at the Golden State Star Party without the solar solution. I don't consider running a generator an acceptable option. I don't want to fool with the gas or the noise.

I am thinking about some ways to put the solar to use when I am at home. I am thinking about buying a couple more large batteries to create a ups solution to provide to keep my home network up and provide a bit of DC lighting in the house when the power goes out.