I'm looking for the amount of electricity hair curlers use. I always
argue with my girlfriend that leaving them plugged in for hours at a
time before shes going to curl her hair must be really expensive. I
don't really know though. But from the way the energy is used, I would
have to think its very inefficient. The set of curlers is 20 pieces,
and they are billed as insta heat, 5 minutes heat up time. Any average
rate would be sufficient.

All technical processes where electricity is turned into heat consume
quite a lot of energy. Here are some average values for the energy
uses of hair-curlers I found out for you :

400 watts
( http://www.diversepower.com/html/watts.html )
750 watts
( http://www.realgoods.com/renew/sizing/watt_chart.pdf )
750 watts
( http://www.unlimited-power.co.uk/powestv2.xls )
350 watts
( http://www.mcecoop.com/acrobat/energyconsumption.pdf )
350 watts
( http://www.belco.bm/belco/belco_pages/energy-calc.html )

Sure it depends on the size of the device, the heating speed and the
amount of curlers heated, but 400 watts seems to be a good average. So
starting it e .g. 2 hours before using it will consume 0.8 kWh of
electrical energy.
Here in europe any electrical device must have a rating-plate where
the energy use in watts is shown. Maybe you can find it on your curler
to find out the exact value.

till-ga

Search strategy:

( ://www.google.de/search?sourceid=navclient&hl=de&ie=UTF-8&oe=UTF-8&q=%22hair+curler+set%22+watts
)
and
( ://www.google.de/search?sourceid=navclient&hl=de&ie=UTF-8&oe=UTF-8&q=hair+curling+energy+consumption
)

I'd be more worried about the fire risk of leaving a heating appliance
unattended for long periods, particularly one that isn't intended to
be used in this way.

Owain

Thanks for the answer. I just didnt want to look myself.

The thermistor switches the curler on/off once it gets warmed off.  So
few hundred watts the first couple minutes, and maybe 50 watts each
additional minute.  Imagine the heat you feel radiated from a light
bulb when you put your hand in front of it.