I go look at my meter.
I used 24 kw yesterday
Summertime I use 20-25 KWH per day. My electric company has these pretty neat breakdowns about how much used this month, avg usage per day, how much used last year for the same month, yada yada
I have cut down significantly from about 28-30 KWH per day last year. So it does work to actually try to be conservative.
I should redo my kitchen fluorescents. I have the old style of four-footers (6X40 watts) and my friend who specializes in lighting says the new ones are way, way more efficient.
Not trying to be nitpicky, but..
The usage is usually described in power per hour so in your case it is 24 kwh. That means about a thousand watts per hour for a full 24 hours.
I also have a kill-a-watt and find it useful in determining the priority in which electrical appliances will be cost effective to replace or completely power off when not needed (by using switch equipped power strips). It only measures 120 volt loads though not 240v. Its very handy for large intermittent loads like a window air conditioner that isn't running all the time.