It's a myth that the sun is better than a zillion grow lights. The light from a 1k light is more powerful at a reasonably close distance than the sun is at the equator at high noon, and the 1k light will be that bright steadily, the whole time it's on, whereas the sun may get shaded by clouds or buildings or trees or whatever during its trip from horizon to horizon.
Yes, the sun is huge and bright. Nevertheless, grow lights can be better. The reason is proximity and the way light intensity decreases with the *square* of the distance. The sun is 93 million miles away, but your light can be 24 *inches* away. And from 24 inches, a 1k light is waaay more intense than sunlight.
The problem is when you have very big plants. Once they grow taller than around 4 or 5 feet, you simply cannot keep the light that close to most of the plant without frying the top. In that case, yes, sunlight may be better. But if you ScroG your plants, you can get a pretty big plant, but keep it horizontal and level to absorb the light better. With ScroG, growlights are king, better than the sun. Without ScroG, whether the lights are better or the sun is better depends on your lights, the height of your plants, and the proximity of the bulb to the plants.
The one area where the sun is unsurpassed is cost. Doesn't cost a dime to run the sun. Heh.
