Yeah, oldemac, I had the same question, thus I asked RackitMan to what lamp power correspond the SPD graph posted, which has scale so it can be calculated.

When they say 96 or 85% of the light may be used by the plant it means its into the PAR range. It not mean the 96% of the watts consumed are delivered as light. Probably, the efficiency of the lamps is about 25%. If its 30%, it would be excelent.

Id wait to some more detailed specs. Can you link the manufacturer page, so I can read whatever technical info they have avalaible?