LEDs can produce concentrated beams of light at specific frequencies of light. While sunlight comprises the entire spectrum of light, LEDs can be designed to emit specific parts of the light spectrum that activate certain photoreceptors in the plant. For example, blue light promotes phototropism and cryptochromes which help germination and elongation of the plant, while red light stimulates phytochromes which help the plant to flower at the optimum time. Regulation of the spectrum of light based on the plants life cycle promotes faster growth, and a stronger plant than what would be produced under sunlight conditions.
Note that the light output of LEDs lessens at higher temperatures. You should make sure that the luminaire is suitable for the environmental conditions.