Introduction: Parts of the 11kV network in WPD have been designed to operate at voltages significantly higher than the nominal voltage. This has the advantage of allowing long feeders and reduced network losses. However, it can also prevent the connection of embedded generation as there may be insufficient voltage headroom and may also result in a modest increase to customer consumption.

Objectives: The study would see if it was still possible to operate the whole network at a reduced target voltage, but still remain within statutory limits. It would identify if there were any significant energy savings to customers by operating in this fashion.

This project involved reducing the voltage by 2% and monitoring the voltage and load data at both the primary and secondary substations along the feeders.