overages for power usage

[Alan Hannan <alan () routingloop com>]

What kind of typical overage costs have you seen when a customer/you use
more than you've committed to?

I'm especially interested in datacenter power situations, where maybe you
sign up for 5kw or 500kw and use more than that in a given month.  Is it
billed at the same rate?  Is it billed at a higher rate?  What's the %
increase of the higher rate versus the regular rate?

Thanks!