Transpower Decommissions Half Of Pole 1
Transpower announced today that it would decommission half of Pole 1 of the HVDC inter-island link and look at
reconfiguring the remaining half pole to be kept on ‘warm standby’ so that it could be used from winter next year.
The remaining half pole would only be available for critical situations where the power system is becoming too
constrained due to high demand for electricity and/or insufficient supply from generators in the North Island.
Pole 1 of the HVDC link was stood down in September pending further investigation and analysis into the risks that the
aging technology posed, and possible remedial actions that could be undertaken in order to return the asset to service.
These investigations have now been completed and the reports are published on the Grid New Zealand website http://www.gridnewzealand.co.nz/n933,147.html. A National Winter Group (NWG) of industry specialists, who meet annually to determine the ability of the power system
to meet winter peak demand, have now completed their report for next winter, available at http://www.transpower.co.nz/?id=6107.
It reflects an industry view that the system can meet peak winter demand in 2008 if all generation is available -
excluding the station at New Plymouth, which is not expected to return to service. Work is underway to provide options
to ensure this outcome is achieved with confidence.
Chief Executive Patrick Strange said that following the stand down of Pole 1 earlier this year, Transpower committed to
a thorough investigation on what mitigation measures could be undertaken to return Pole 1 to service, and to uprate the
existing Pole 2 to 700 MW.
“The investigations – technical and environmental - are now complete and have provided a number of scenarios for us to
consider. We will now need to review what remedial measures could safely and economically be undertaken to make a half
pole available at times of critical demand.
This is expected to be a limited number of days during the winter for northwards transfer only.” “We are continuing with
our analysis and are in contact with our customers on the process of reconfiguring a half pole. We expect to be able to
make a decision well before winter.
Mitigations would then take around four months and we will work towards making a half pole available for use this coming
winter for critical situations, should it be needed.”
“Reconfiguring the undersea cables, which increases Pole 2’s capacity from 500 to 700 MW, was also completed
successfully this week in order to maximise the capacity of the HVDC link while Pole 1 is out of service.”
“Transpower still considers that a complete replacement option of Pole 1 is the best long-term solution. We are
continuing to work as quickly as possible on possible solutions to replacing the old technology and expect to go out to
consultation in February 2008.”
ENDS