250 watt HQI ballast.

[Delphinus]

If there is something like that, my guess is it's minimal or negligible. Of all the stats/specs I read about ballasts, they all more or less have the same "wattage" (which is roughly amps times voltage, give or take) regardless of what input voltage is used.

Thus I'm not real sure that it's a "benefit" nor a "deteriment" to run them off 220. Like powerboy said, it's half the amps, but it's twice the voltage. Six of one, half-dozen of the other? I guess it's more a matter of whatever's convenient. If you have to run some new circuits/wiring/breakers anyways, you might as well just do the one for 110 and be done.

But, on the other hand, .... the wiring for 220 is presumably going to be heavier guage and thus there ought to be less resistance in the wiring. Therefore it might be conceivable that there is some slight gain in efficiency (rather, a reduction of loss, or something like that), but I can't imagine if that really translates into a noticeable reduction in your power consumption... I have no idea.