Are LED lights better than HPS or metal halide? I found a good answer here: http://gardeningunlimited.com/2013/05/01/are-led-grow-lights-better-than-hps/
In short....not yet. Low heat output from LED results in temperature problems causing water logged roots from soil not drying and other related issues. Mitigating these issues may result in offsetting any money claimed to be saved by using LED.
In short....not yet. Low heat output from LED results in temperature problems causing water logged roots from soil not drying and other related issues. Mitigating these issues may result in offsetting any money claimed to be saved by using LED.