I found the site for yours, and all it said was that they had 3-4 times the lumen output as their 55w halogen counterpart.
So check this out, and whichever one yours is the replacement of, and multiply by 3 or 4. My guess is your probably getting around 5500 lumen with it.
Halogen

But I honestly dont know. Never seen someone try to grow with em. Might as well try if your not in a position to get a HPS. Im all about experimentation!:greenthumb: