The Authority has refined the focus of the Extended Reserve project to achieve a secure transition to a 4-block automatic under-frequency load shedding (AUFLS) scheme in the North Island. We have been working with the system operator (Transpower) to develop a proposal for the scheme and determine the technical challenges faced by providers.
AUFLS is the mechanism used to shed large blocks of load to prevent the electricity system collapsing if there is a rapid fall in system frequency.
In October 2017, the Authority paused the Efficient Procurement of Extended Reserve project to resolve technical issues. Since then, we have been working with service providers to investigate these issues and develop an improved AUFLS scheme.
The proposed transition from 2-blocks to 4-blocks would reduce the size and increase the number of AUFLS blocks provided by distributors. This would mean that potentially fewer consumers would be affected by a significant loss of supply.
This complex project is expected to take 4-5 years to implement. The Authority and system operator will be contacting North Island distributors and direct connect consumers shortly with the next steps.