250 watt HQI ballast.

[powerboy]

yes, thats pretty much what it boils down to. amps drawn are half, so you can essentially double the load.

just remember, at startup, theres quite the surge of power, so keep that in mind when calculating.

as for power consumption, its going to be the same regardless. what bc hydro pumps into our houses is single phase power, and its quite inefficient.

theres an equation used by the hydro companies to allow for wasted power (i think its called the pfc. power factor correction) essentially its for situations when current drawn doesnt follow the voltage (goes out of sync) in any case, its to their benefit..

im getting to technical for myself here

i guess my point is, 220v is great. if you have the opportunity to use it do so!