A new mobile substation will be used for the first time at Murchison, New Zealand, to provide power supply to the region while maintenance is undertaken on the local network.

The mobile substation is the largest in New Zealand and can be plugged into the electricity network so that maintenance can be carried out at smaller 110-kV substations without turning the power off to communities and townships for extended periods.

Transpower General Manager Grid Development John Clarke said that the mobile substation provides great benefits for both Transpower and communities around New Zealand.

Mobile substation"A number of small communities around New Zealand are fed from a single transformer or transmission line with no back up supply when maintenance is required. The use of the mobile substation will remove the need for day-long power outages for these remote, largely rural communities. It will also reduce the need to undertake costly upgrades to these smaller substations."

"We will be able to substantially reduce disruption to communities by maintaining power supply during maintenance. Even with advance planning, the power shutdowns each year inevitably fell on days where there were local community or major sporting events and this disruption will be reduced, and in some cases eliminated, going forward," he said.

The 70-ton specialized compact equipment and transformer took 12 months to design and build. It uses two 17-m-long trailers so that it can be transported around New Zealand to where it is needed, when it is needed.

"The mobile substation provides greater flexibility for maintenance work and helps to improve safety as it removes the time pressures to complete all work to restore power within a required time window. The mobile substation will also be used in emergency situations where power supply has been affected by unforeseen events and repairs cannot be made quickly," Clarke said.

The mobile substation’s first job is in Murchison, just outside of Nelson on Nov. 21. Tekapo and Mataroa will be the beneficiaries of the mobile substation once the Murchison outage is complete. This work would not have been previously possible without significant disruption to customers.