If you have ever had a premature lighting ballast failure or equipment drive failure, then these could very well be caused by harmonics.
A harmonic current is caused by non-linear loads connected to the distribution system. A load is non-linear when the current does not have the same waveform as the supply voltage. These harmonic currents are generated by industrial equipment as well as electrical equipment in offices and usually result in soaring electric bills. A harmonic study can save energy which, in turn, can save costs for your facility.