I am growing some herbal plants that require a delicate balance of lights and nutrients. Unfortunately it's not always sunny where I from, so I grow indoors. I setup a LED blue/red 255 tiny light system 12x12 inch over the small flat of rosemary/chives...etc. How close should it be and will it be effective? I want first hand experience.

Leaving the issue of safety aside, would it be cost efficient to have LED street-lights "turn-on" only when motion is detected ? Or would there be some problem with there being frequently repeating cycles---too many "offs and ons"? If feasible, would savings be significant, over, say---LED without motion detection?

My friend and I interested in various commercial products for home use as a replacement for regular light bulb, our preferred solution is that it should be based on LED technology. The perfect thing will be to find a light bulb that is in fact a LED light and can fit any location without any modification, just buy and install.

LED lighting uses much less electricity than normal lighting, doesn't it? So, why isn't it used instead of conventional lighting?