So.. whats the verdict?...
Hmm.. what are the issues.. heat, cost and light spectrum.. I think that's a good short summary of the important issues.
Cost is an easy one... total no brainer. LED's are roughly 40% more energy efficient than HID's and will run about 20x longer (literally 20:1 ratio). So at the end of the day with LED's you'll be buying less lights, less often, and they're less expensive to turn on... For the best LED's however you might spend as much initially has an HID!!!!..Round 1.. Ding Ding...LED!!! Winner by decision!!
Heat: HID's produce a lot of heat, heat stress can be an issue and LED's just don't get as hot. You don't have to wait for LED's to warm up or cool down. If you're anything like me you'll be tinkering here and there and you'll most likely end up touching a hot bulb at some point... not pleasant. More heat also means more potential air handling costs. I will say however, your choice can depend on your space, if you have a enough space, heat might not be an issue for you. But rubber meeting the road and all... Ding Ding... Round 2..LED Wins!!!
Light Spectrum: Hands down HID's are the best at mimicking the sun. In the past LED's have struggled with the green light part of the spectrum, but are getting better, radically better. High end LED's now come VERY close to the spectrum that HID can deliver but technically HID's(specifically HPS bulbs) are still better. Especially at flowering. This round is like 2 evenly matched guys and one guy gets a fast 12 sec KO...Ding Ding...Round 3...HID Wins!!!
There are a lot of things to consider when choosing grow lights...it seems that LED's would be the way to go, but that bud/flower is usually the most important part so it may be worth the extra cost to get HID's.
You decide!!
I think the best thing you could do whether you are growing for yourself or commercially is write out and articulate your plan in a business plan form. Your plan should include all the variables in which purchasing decisions will be important ie, space size, air handling limitations, plant, strains, electrical limitations, projected yields, and budget etc...Having a clear concise plan will ultimately help you choose the best lighting set-up and get you the best results over time using the resources/tools you have to work with.
Its easier to get to where you want to go, when you know where you are, and have a map, that plan is your map!
Thanks for reading!! Cheers!!
-Nat
ps.... Good LED manufacturer's..Bridgelux, Cree, Phillips, Edison, GE, Osram, Zhaga, Prolight Opto