Transpower’s mobile substation in action for new windfarm connection

11 August 2020

Transpower’s 70-tonne mobile substation has been sent to Waverley substation in south Taranaki to keep power on to the community over the next few months while Tilt Renewables’ new 130 MW wind farm is connected into the National Grid. 

The twin-trailer mobile substation is hauled to smaller regions by Transpower when significant work is needed on a supplying substation.  In this case, without the mobile substation, it’s either lights off to Waverley and surrounding areas for long periods of time or diesel generation.  Transpower’s Regional Services Manager, Brendan Olsen explains:

“The mobile sub has everything needed to keep a small community’s power supply going when work is needed on the fixed substation.  We just connect into the incoming high voltage line and connect out through Powerco’s lines that supply the local community.  In between, the mobile substation transforms the voltage down from 110,000 Volts to 11,000 Volts suitable for Powerco’s distribution network. This then allows us freedom within the fixed substation to do the work we need to cater for the new windfarm.

“Without the mobile substation, on-site diesel generation would be needed to keep power on over the next three months.  But that sort of option doesn’t stack up in a decarbonising world – particularly when we’re connecting in new renewable generation.   The mobile sub feels a much more appropriate solution.”

The work at Waverley substation includes extending the switchyard to accommodate the equipment needed for the windfarm connection, as well as some major maintenance work which involves refurbishing the steel structure and painting the transformer that has been coordinated to occur at the same time.

“Normally, we need to take the substation out for about 8 hours to do regular annual maintenance, meaning a loss of supply for consumers.  But this year, by coordinating with the windfarm work, and using the mobile substation, there will only be inconvenience of a few minutes of supply interruption to consumers, so that’s also a good outcome here.”

The connection of the new windfarm is expected to be completed by early November, and then the mobile substation will be packed up and transported to its next tour of duty at Ohakune substation.



For more information contact: Geoff Wishart, Stakeholder Engagement Manager 021 574 877


Mobile Substation at Waverley MR [ pdf 90.67 KB ]