Hi there...I want to build an automated light system that turns on automatically when dark...the if I used solar panel...and light about 10 LEDS each for two lamps...(I think this for now..... what do you suggest better??)...and most imp question is...how do I select the solar panel....and any recommendatoin on the supplier...(preferably in the netherlands....)

 

How do you expect to turn on the lights in the dark with a Solar panel?

You need a battery backup supply to put the lights on and use the solar panel to charge up the battery.

 

You select the panel last. First you look at your load: count up how many LEDs are on for how many hours to compute the amp-hours for the load. Call that X.

You need a battery that can supply that, actually more then that. A minimum battery capacity is 2X, and some "need to always work" systems will use 30X. That gives you how big battery to get.

Now the solar panel: as charging is not 100% efficient you needs to supply a minimum of 1.25X every day, even on the shortest winter day, and even more if the day(s) before were cloudy. So that's going to depend on your weather and your latitude as to how much "over the top" you need to (and can afford to) go over.