Wow, that's a lot of LED wattage. I have only played with the weaker ones, but I positioned them literally on top of the plants (they still cost $100 a piece). The thing is for the cost of electricity vs. the cost of initial equipment cost, florescents are the best bang for your buck.Originally Posted by plantmattg
Assume your 250 watts of LEDs is equal to about 560 watts of florescent.
7x shop lights @ $10 + 14x bulbs @ $1 = $84
vs.
2x 125w LED arrays @ $450 = $900
Assume a 12/12 light cycle. With a 300 watt difference, it would take:
(12 hours / day) x (0.300 kilowatt / hour) = 3.6 kWh / day @ $0.10 per kWh = $0.36 per day
THEREFORE:
$900 - $84 = $816
It would take... $816 / ($0.36 / day) = 2,267 days or just over 6 years of daily operation for the LEDs to start saving money on the fluorescent bulbs. (In reality you would have replaced the $1 bulbs about 3-6 times here, but I did round down on the years.)
So, from a practical standpoint it is cheaper to start-up with some fluorescent. It is also cheaper to replace them if something were to go wrong. Lastly, some people only use them during the winter months. In some cases to start seeds. If they were only used 3 months out of the year it would take 24 years for LEDs to be cheaper. By then, we will have some fancy laser lights or better.
My indoor hobby lasted about a year before I went outdoors with it, which is why I couldn't commit to the LEDs. I wasn't sure how long it would take, but I knew it would be cheaper to get some fluorescents. I ended up using them around the house once I dismantled everything; so, not much wasted money... at least that's what I tell the old lady!
One more note as far as which is better. I did compare a 16 Watt LED array on 1 species plant vs. a 16 Watt CFL bulb on the same species of plant (Capsicum annuum). I positioned the lights 1-2 inches from the plant (adjusted daily as the plant grew). Over the entire course of the plant's growth, the CFL clearly outperformed the LED. In the course of the growth the LED plant never got large enough to produce peppers although it flowered some. The plants were in the same aquaponic grow bed divided by a divider so light didn't pass. I didn't record the data, but all the other variables were equal. Maybe I had an inferior LED product, but Watt for Watt the CFL beat the LED hands down. I would love to see this done using the higher end LED lights, but don't by those cheap ones (and they're really not that cheap in price just cheap in quality).
With all that said, I would happily set up some high-end LED arrays if they were a gift!