An excerpt from said article....
Depending on your plant variety, two to three of our 250 Watt LED units will cover a 4x8 ft growing area, producing a rapid 'rain forest like growth cycle with quality fruits and or flowers. This is the LED effect but only if the LED unit has enough raw LED power and the circuitry to handle the electrical current to achieve peak performance. Be advised you may have to use more LED's than you have been lead to believe in order to the raise certain varieties of plants that really appreciate lots of extra sun light.
Now, a sampling of the Q and A beneath this article....
Q: Why is the unit so much more expensive that conventional lighting? How can I justify to my wife or customer or myself for that matter that spending the extra money on the LED light system is worth the investment?
A: First, the cost of our system is comparable to other LED lighting solutions. Due to the quality of design we feel our product is dollar for dollar, watt for watt is one of the best products available on the market. Our cost reflects the current cost of the technology. Also our system is made in the United States and we do out source for cheap parts or labor. When compared to the cost of a sodium or halide lighting systems, the money that is saved in electricity costs in one year will have paid for the increased cost of the light.* Also the light system is rated at 50,000 hours of longevity. No more replacement light bulb expense will also add to your savings.
Since they say they are comparable to other L.E.D. systems without actually stating their prices anywhere, I'm forced to go to another vendor for an idea of what these lights cost.
I searched and found a bunch of 45 watt panels, but I wanted something comparable.So, I found this.
http://www.4hydroponics.com/lighting/superNova.asp It IS 20 watts more than the one you described..sooo I'll knock off 100 dollars.That brings it to 849.95.Yes.Not a typo.For ONE light.The article says you need three to cover a 4 by 8 growing area. Which would be around 2600 dollars.AND!250 plus 250 plus 250 is..anyone?750 watts. So, let's compare this...with a 600 watt HID.A nice one, with a digital ballast,mh conversion bulb...complete system.
http://www.htgsupply.com/viewproduct.asp?productID=48969
with tax....it comes to 272.64.So, not only are you saving 150 watts in electricity..because watts are watts, no matter what they come from, we all know....you're saving around 2300 dollars.That's if I knock a hundred off of each L.E.D.
So..uh...those L.E.D's better clean my house, grow me some fat nugs, and make sweet love to me for THAT much.