Hi I have been playing with LED lighting in my home. I have a special interest in Solar PV systems and have a 1/2KW system on my home although I am conected to the grid. Recently I have been playing with a small stand alone LED lighting system in my verry small home actually a 2 bedroom condo. On ebay you can get some verry nice 3.2 Watt car battery maintainers which are made for VW and they ship all the new cars form the factory with one. They are made with poly crystalin cells not thin film and they have a charge controler inside the cigaret lighter conector. You can usually pick them up on ebay for $20-25 after shipping. I am using a 7AH 12V battery which I stole from my Thor spotlight, it is charged by this small panel. The panel actually can get up to 200MA of charge curent. I figure it gives me a little over 1 amp hour a day. I then have 3 luxeons, one in the kitchen/dining room, living room, and bathroom. They are wired in series and are conected to a controler that I made for them. It is a set of 2 switches wich can be used to set the output to hi, medium, low, and off depending on the switch combination. Hi = 500ma, medium = 150ma, low = 20ma. The low makes a great night light.
The part that may be especially usefull for your aplication is the newest set of LED's I have been playing with. I got my hands on some of the 1.5 watt white UFO Starfish LED's each one can be driven directly of 12V with a 10-15ohm resistor which will give you about 150Ma each. I put up 2 of these guyes in one bedroom and 1 in the second. The nice thing about them is they can each be independently conected to a 12V source like you described in your home and then at the junction box you can set up a switch fo them all and use some resistors to dimm them down inside of your controle box.
I have to say they are bright. Probably brighter then a luxeon but much more on the bulish side of the white spectrum. I also made a second switch setup for these starfish so that I can dim them down to a verry low curent and let them run all night long. I do not know how the Starfish LEDs will hold up over time but I am hoping they will do well.
I got my UFO Starfish LEDs form
LED POWER for $5.75 each and $5.00 shipping. Not a bad price for a great led.
I now rarely use any of the interior lights in the house, and when I do it is only for a short specific task. The 6 LED lights and the One little 3.2 Watt solar panel meet nearly all of the lighting needs that I have in my home. with all the LED' on HI power they draw a little over 900Ma,
all of them on madium is about 300Ma which is still quite bright, and all on low draw about 40Ma.
I hope all this rambeling helped some. I would like to do a full right up on my system with pictures and all but I need to find some way to host my pictures on line?