Light-Emitting Diode (LEDs)
LEDs have been quickly making a name for themselves, with some claiming that they produce some of the biggest yields while being the most heat effective. There is some truth in that claim, but with them being still somewhat newish to the scene it’s hard to tell. But, personally, I don’t think the technology of LEDs are there just yet to match HIDs when it comes to yield/watt.
Pros Cutting Edge: LEDs are quickly coming down in price and some will want to lead the charge and grow with the lights of the future!!!
Stealth: LEDs produce little heat until they get really large in size. They also have a built-in heatsink that allows them to disperse heat evenly and not directly on plant.
Expensive: They might be cutting edge, but that means they are also expensive. They are quickly becoming much more affordable however, and in the coming years this will become even more apparent.
Heat: Where there is light there is also heat and just like the other lights LEDs will need an exhaust system. They also have a catch-22 because some growers rely on lights for heat and LEDs have to be so far away that often they can’t raise the heat enough.
Light Damage: LEDs can be way too powerful and can cause light burn and bleaching when they are too close to the plants.
Expected cost: LEDs are rabidly coming down in price and around late 2016, early 2017 a lot of home growers are switching to chinese made LEDs. Currently, you’re looking at $80 for 300 watts or 132 true watts.
I’m going to spend some extra time on LEDs since they cause the most confusion, but look to be the light most growers will end up using.