A 65W CFL bulb is not 500W equivalent, more like 250, and LOA has a terrible habit of over-rating their bulbs...

That "500 watt" equivalent, if you read the fine print, means that humans can supposedly see as well at night by the light of this lamp as they can by the light from a 500W metal halide lamp covering an equivalent area. Even assuming that's true, it means very little in terms of its equivalence for growing plants.

Personally, I think the the coiled and bunched-together U shaped compact fluorescents are vastly overrated as plant lights, but some people seem to think otherwise. When I hear from people who've used them for longer than a few months, I may change my mind but for now I think the long, single tube-deep types (commonly called "biaxial") with a good reflector are the way to go if you want to use CFLs.

As for this specific Fluorex lamp/fixture, I used one for a while and found it much less than desireable. The hood gets very, very hot, it didn't cover much area with decent intensity, and maybe because of the heat build-up the lamp life was shockingly short (about 9 months). The ballast in the replacement lamp didn't last 2 months before the lamp started flickering but would never fully catch on. At that point I gave up on it and if I need to light that same area again, will go with a 55W biaxial. If you want bright light over a very small area the "Fluorex" lamp might be of some use, but that's about it.

i have started using these lights on one of my shelves so i'll see how well the plants do over time. regardless, that is a great price for that light. people sell the same ones on ebay (advertised as "grow lights") for $50.

i just realized that the link you posted is for a utility company. most likely, you need to be a current customer in order to qualify for the special price.