I know because my Clamp meter tells me so.

I measured more things tonight. Amps, just multiply by 120 to get watts.
A/C system: 10amps
Oven: 15amps
stovetop: 8amps per top, 11amps for the big one
100W CFL: .1amp
40w incandecent: .35amps
computer + LCD: 1.2~amps
40Watt hot glue gun: .35amps
4x cfls + one fan: 1amp
hot water heater: 15amps
250W HPS: 3.5Amps

so me running my a/c system is like using almost 3x 250W HPS lights.
Too bad you cant cycle the HPS Like the A/C....