first time trailer owner

[anomar]

I just bought a trailer in a natural trailer park so there is no electrical hookup.  Many of the trailers around have solar panels on the top of them and others just use batteries.  I would like to have a solar panel to keep my battery charged.

Since I just bought the trailer and paid for my site fee for the year I would like the most cost effective way to do this.  We plan on using power to run the fridge and possibly use a coffee maker or toaster occasionally.  Lighting is not a concern and we will not be running the lights in the trailer.

I've been looking at the Canadian Tire 15 watt Eliminator solar panel and the price is certainly right but I'm not sure it is enough.  Would I need to purchase anything else to go along with it such as a charge controller?  I really have no idea about this kind of thing.  I've looked around at RV sites and many of them suggest expensive systems but I don't think we need that as this is just a place to go on the weekend and the only thing we aren't willing to go without is a fridge.

Anyone have any advice for me?

Thanks!

[ghurd]

Coffee. 10 minutes at 700W.

A 15W solar panel at 5 hours solar insolation per day.

Thats a pot of coffee every other day.

Toaster? Yikes!

Fridges vary, but same idea.

Anything that gets hot is bad for solar.  Use a propane stove for a coffee perkolator(sp), toast, and the fridge if it is that kind.

Solar is great for lights.

G-

[anomar]

Well the coffee maker and the toaster were not really that important anyway!  I actually just found out that the fridge runs on propane...I had no idea.  I am a real city girl and all this is very new to me.  

So I think that maybe the solar panel that I was asking about will be enough just to keep the battery charged for emergency use.  

[ghurd]

You can get some use out of it, for lights, charging a cell phone, etc.

Change the #1156 bulbs to #1141 (less power), maybe 12V CFL lights where they will be on long.  Be carefull with 12V CFLs running from a grid powered RV, often the 12V in the camper while connected to the grid, is 12V "AC" and poorly regulated (meaning well over 12V).

It would be very handy clicking a light switch, instead of looking for the darn flashlight.

G-

[richhagen]

As Ghurd said, Fridges and coffee pots and such use a lot of power.  A 15 watt panel would not be sufficient.  Fortunately, your fridge is propane, so that is not an issue.  With solar, you can start small and add more panels as money and time permit.  Where you end up in the longer run is usually redundant systems to keep your batteries charged.  Solar, with wind power, and a small generator for when it's dark and calm and you need power.  Most systems are only available part of the time so the redundancy is important if you want to keep the lights working.  

In general for a small 15 watt panel, you can connect it with a diode and a fuse in series with the lead to the positive battery terminal directly if you use a diode rated for the maximum current of the panel provided it is a flooded type lead acid battery of a capacity of about 100 amp hours or more.  Then as funding permits, you can add a charge controller to prevent over charging your battery or batteries and more panels.  

I am not a fan of the amourphous type panels like the one I believe you are looking at.  I prefer glass encapsulated panels of the type that usually come with a 20 or 25 year warranty when new, and all the new ones generally come with a junction box on the back.  I have some panels from Aarco and Siemensof this type (except that the Aarcos have screw terminals on the back instead of a junction box) that I obtained used that are probably more about 25 years old and still work great.  I also have some Photowatt panels that I bought new about 5 or so years back.  Panels of this type of construction (glass/eva encapsulant/ glass or steel or tedlar backing) have never given me a lick of trouble.  I have an ICP panel, and some other amorphous, thin layer type panels where the backing started peeling off after a year or two of exposure to the elements.  The only thin film panels I like are the UniSolar for some applications, and that is because they have held up aside from a yellowing of the front plastic, and then only when weight, shading conditions, or breakability are a factor.  These are just my opinions, I don't sell or have a financial interest in any panel manufacturers/sellers that I am aware of, I just use a few of them.  Rich    

[Ungrounded Lightning Rod]

You're thinking way to small.

Of course you're not going to run heating appliances off solar power - even stored solar power.  Ditto air conditioning.  But a trailer has a lot of loads, and they're usually not all that efficient.  You get maybe 5 solar hours (hour of noon-equivalent light) per day, so a 15 watt panel will give you about 5 amp-hours of charging.  That's enough to run one light bulb for four hours.

Your battery might leak that much power in a day.  A 15-watt panel is good mainly for keeping your battery charged when the trailer is parked in storage.

You'll have a LOT of loads in a trailer:  Propane detector.  Motors in a propane furnace.  Modern propane fridges have a computer and a selonoid to turn on the gas, and just the selenoid pulls more than an amp.  Vent fan for the bathroom.  Stock lighting is, of course, incandescent.

My self-contained camping trailer had a couple 95 amphour batteries and they were good for no more than two nights if it was a heating season.  It was designed to be charged as it was towed, and plugged in at night except in back country.  So an overnight or weekend's camping was all the manufacturer had in mind for power storage, despite fresh and waste water storage good for at least a week.  And we bought it off the lot so it didn't come with the optional hookup for rooftop solar panels.

So you're going to want at least 200 watts of panels, and 400 would be better, if you aren't going to have a power hookup or run a genny and have loads like mine had.

If you're on a windy site (and not too close to neighbors) you might consider a small windmill, like our correspondent from Alaska uses.  Either instead or (better yet) combined with solar.  In many climates it's windy when not sunny and vice-versa.

[Phil Timmons]

Might consider some type of solar cooker or solar oven.  They seem a little funny, but I was watching a couple of them do their thing, today, and they really work.  Boiled a pot of water in about 5 minutes, and the oven cooks chocolate cookies.

We were just setting up a Renewable Energy display and booth for Mayfest in Fort Worth, Texas, today.

Our site has a windmill, solar PV arrays, and a couple of solar oven/cookers -- and a solar powered toy electric train for kids to ride around.  Pretty cool, actually.  I will post some pictures in the "Diary" section in a couple of days.

Anyway, those cookers seem pretty good for Summer and would take the cooking heat outside your trailer.   They are really just a collection of mirrors with a frame or array structure around them, so there is no PV equipment and no batteries related to them.

[tecker]

I don't know how you'll be traveling but possibly the trip there might be enough to charge several marine batteries with the cost of some charging wire and short protection . Leaving the the batts in the car or truck and parking close will give some options with a Quick disconnect . Then the 15watt could stay with it's local battery to run lights possibly led replacements . With the gAS appliances your set .I make toast with a bacon press very fast and pre buttered.