I run my 'dark' hours from noon to 6 during vegging ... this way, the heat given off from the lamps is done during the coolest times, and the warmest time of day wont have added heat ...
I wouldnt worry about showing 'too much electrical usage' with the setup you have , hell, a color TV commonly will pull 600 watts by itself, my microwave pulls 1400 more ... no biggie ... :smokin: