If you want a good price on a 100 watt solar panel, check this place out.
SunElec.comThey would require a controller to shut off the charging at 13.5 - 13.8 volts. IF the panel is a "12" volt nominal - that is 19 - 21 volts open circuit, then a PWM controller can be bought for about $65 for a 6 - 10 amp model, and a small amount more for a 15 - 20 amp model.
If you get a higher voltage, such as the 39 volt open circuit solar panel, used mainly in homes, then the controller needs to be a more expensive MPPT controller, where a 25 amp controller might cost $250 or so.
You can use the battery already in yur RV if you will be using the inverter and solar panel in the RV. Normally a group 27 battery can store about 105 amp hours, or about 1,200 watts. A group 24 is slightly smaller, 85 AH and about 900 watts.
To this you can connect a inverter of your pick, a 150 watt one will recharge a laptop, run a small TV set, and a ink jet printer all at once. That is about all the load you want to put onto a small batttery system, yet you can buy a 300 - 500 watt inverter if you desire - about $30 - $50 at the most if you are shopping around.
So in general, it is less expensive to buy the solar panel, inverter, controller and battery at separated prices, than to buy a "Package deal" that is all inclusive, but marketing costs make it really expensive for what you can get elsewhere for a lot less in many cases.
I have seen one system rated at "1,200 watts". It included a "solar panel to recharge the batter from the sun" "A battery" and 1,200 watt inverter.
The fine print (if they even tell you that) is that the solar panel is only rated at about 60 watts, to it would take 20 hours of full sunshine to recharge what the inverter can take out in 1 hour. The battery will not store 1,200 watts total, so could be discharged in less than a hour if you hook up a 1,200 watt load to it. But will last for many hours *If the load is much less than 100 watts*.
By the way, when I say it takes 20 hours of full sunshine to recharge the battery, it actually means 20 hours when it is as bright as noon, in a clear sky. So as a average, it means you can collect about 5 hours of that much power each day, or about 4 days to recharge a 1,200 watt battery that was dead.
So I am warning you to make sure that you are getting a good price for the items included in any package. If it includes a 100 watt solar panel, 10 amp controller, and group 27 battery, and a 300 - 500 watt inverter, then it might be worth the following.
100 W solar panel from SunElec.com is about $100 - $125.
10 amp controller from several sources is around $64 - $75.
A group 27 battery from Costco is around $87, if you pick it up locally, then no additional shipping charges for this heavy 50 - 60 pound battery.
Costco sold a 500 watt inverter years ago for about $35.
So if the total cost for a system put together - including shipping is less than $300, it is a great deal. If more than $400, then not such a great deal. If more than $600, it sounds like the "Average" price for a retail system installed someplace. If they are including a cart to install the battery box, solar panel, and other items, it is not required to use in your RV, but must be part of some packages. So that cart is included in what you might need to pay for to get the package price, but is not realy something you would need for a RV installation.
So I hope I provided enough information so that you can compare the list price of any system against the suggested retail prices of the items bought at a solar supplier that is selling for a very low budget price.
Fred.
Money can't buy happiness but somehow it's more comfortable to cry in a
Porsche or Country Coach!
If there's a WILL, I want to be in it!
I havn't been everywhere, but it's on my list.
Kangen.com Alkaline waterEscapees.com
