This project entitled 'The Economic Impact of Poor Power Quality to New Zealand' aims to identify the most problematic and costly power quality issues for industry and residential customers in New Zealand. The economic cost or poor power quality will be used by the EPECentre in their future power quality work. Some recommendations are included from the researcher where appropriate. Society is becoming more dependent on computers and digital circuitry. Industry, commercial and residential users are now dependent on a reliable, high-quality electrical power source to ensure these devices are operational. Electricity supply, however, is not perfect and when electronic equipment encounters electricity that is not of a regular sinusoidal waveform, loss of performance or failure may occur. These issues are termed power quality issues and include: • Voltage sags • Surges • Transients • Harmonics • Momentary power interruptions