as far as the fan....why not just use one of your biggest fans? throw a y connector on the ducting...if you dont want to add another fan.
to be honest, your fans, pumps, and other things will draw electricity....but it should draw that much where you'd notice it!
im willing to bet your OP will run an extra 60-70 tops!!!! maybe more because im not sure of the kwh rate in cali!!!!