Transgrid has recently published a Project Specification Consultation Report (PSCR) for complying with reactive margin requirements at Beryl.
As set out in our revenue proposal for the current (2023-28) regulatory control period, and most recent (2024) Transmission Annual Planning Report (TAPR), we have identified reactive margin shortfall (and voltage) issues in the Beryl area, arising from current and projected demand in the downstream Essential Energy distribution network.
While load at the Beryl BSP has grown in recent years, to a current winter peak of 82 MW and a summer peak of 77 MW, it is now forecast to remain relatively flat going forward. However, we estimate that based on these demand levels, during a contingent outage of Line 94B (between Beryl and Wellington), the current network capacity would likely need to be limited to 68 MW in order to alleviate reactive margin issues and avoid complete voltage collapse in the Essential Energy network.
Our planning studies show that there is currently a risk of breaching the NER obligations regarding reactive margin requirements in our network if an outage of Line 94B occurs during peak winter demand, particularly at times of low or no local renewable generation. Without action, this would breach the defined reactive margin requirements in the NER, as well as result in substantial expected unserved energy to end consumers due to potential voltage collapse in the distribution network.
We have therefore commenced this RIT-T to assess the options available for meeting our reactive margin requirements to avoid these consequences and continue to maintain compliance with the relevant NER standards.
We consider this a ‘reliability corrective action’ under the RIT-T as the proposed investment is for the purpose of meeting externally-imposed regulatory obligations and service standards, i.e., Schedule 5.1.8 of the NER.
Transgrid welcomes written submissions on materials contained in this PSCR. Submissions are particularly sought on the credible options presented and from potential proponents of non-network options that could meet the technical requirements set out in this PSCR.
We consider that non-network solutions that can provide dynamic reactive support may be able to assist with meeting the identified need. Alongside the PSCR, we have issued an Expression of Interest (EOI) specifying the type and form of information we are seeking from non-network proponents to enable their solution to be considered in this RIT-T. Submissions to the PSCR and responses to the EOI are due on 20 February 2025.
In accordance with the requirements of the National Electricity Rules, a summary of the PSCR is made available on the AEMO website. A copy of the PSCR can be obtained from Transgrid’s website or by emailing regulatory.consultation@transgrid.com.au