A combination of below average inflows in Aotearoa’s hydro generation catchments, constraints in the gas market, high electricity demand in May and recent low wind generation has contributed to a rapid decline in hydro storage.
By mid-August, hydro lake levels were just 51% of average for the time of year, which is among the lowest levels we have reached in around 90 years of historic records.
We’ve stepped up our security of supply reporting as a result and are working closely with industry, government and other stakeholders to monitor and manage the situation. We will post links to all relevant information on this page.
Final decision to raise the Alert Contingent Storage Release Boundary
We announced our final decision to add a new buffer to raise the Contingent Storage Release Boundary (CSRB) for a limited time on Thursday 22 August 2024. This new increased buffer increases the Alert Status curve to give industry greater flexibility to manage emerging security of supply risks through access to contingent hydro storage
Thank you to everyone who submitted on the consultation. Our final decision takes into account the views of industry and other stakeholders that we received. The final decision and submissions are published on our Invitation to Comment page.
The decision was largely supported by industry and will allow generators to access contingent storage at lakes Tekapo, Pūkaki, and Hāwea if a security of supply alert status is triggered. While storage levels tend to increase in spring as rain falls, this will give industry increased flexibility to respond to reduce system security risks if the situation continues to deteriorate.
We initially proposed adjusting the Alert CSRB buffer to raise the alert curve only for September. In response to submissions, our final decision increases the alert CSRB buffer for September and by a smaller amount for October to raise the Alert curve for both months. This provides generators greater ability to respond to security of supply risks if inflows from rain and snowmelt are slow improving.
For further information please contact us at [email protected].
Reporting | |
| Daily Reporting Page | When the security of supply risk increases towards Watch Level we start reporting daily on the hydro storage position and the generation mix as well as provide advice on outage changes and market events. The report is published daily on weekdays on the Daily Reporting Page of our website. |
| Market Operations Weekly Report | This forms part of our normal reporting for security of supply. The Weekly Report is usually published on a Tuesday and provides key insights on the market performance, generation mix and security of supply status. Each week a market insight is provided drilling into key industry topics related to the system operator. |
| Electricity Risk Curves | These show New Zealand and South Island storage plotted against electricity risk status boundaries. We usually update these monthly but will switch to updating fortnightly. |
| South Island Capacity Margins | South Island capacity margins for N-1 and N-1-G. |
Other Information | |
| Q&As | We will update this questions and answers document at regular intervals. |
| System Operator Industry Forum | This is a fortnightly discussion of current operational and market issues. We will switch to holding these weekly while we are managing the emerging security of supply risk. Further information and links to video recordings and slides can be found here. |
| Outage Watchlist | This watchlist identifies the outages that may negatively impact security of supply as a result of abnormally low hydrological conditions. The impact of each outage is also identified (as either high, medium or low). This watchlist will be used to inform conversations with asset owners about rescheduling outages that negatively impact security of supply. POCP searches – outage watchlist Pre-configured searches reflecting the Outage Watchlist in POCP are available below. They look out over a 12 week period from today’s date. Constrains off non-hydro generation Constrains on hydro generation |
| 2024 Lower South Island Low Hydro Security Issues and Options | This document outlines the system operator’s assessment of system security issues due to the prevailing Lower South Island low hydro situation and potential mitigations |
Policies and Learning Material | |
| Security of Supply Assessment | The assessment uses forecasts of electricity supply and demand to assess the ability of the electricity system to meet New Zealand's needs over the decade ahead. |
| Rolling Outage Plan | The Rolling Outage Plan provides for the management and co-ordination of planned outages as an emergency measure during energy shortages. |
| Emergency Management Policy | The Emergency Management Policy (EMP), sets out the steps that we will take, as a reasonable and prudent operator, during an extended emergency. This includes the requirement for us to initiate an Official Conservation Campaign under pre-determined conditions and, if needed, manage and co-ordinate planned outages as an emergency measure in anticipation of, or during, prolonged energy shortages. |
| Learning Material | This is a range of material that we have produced to help participants better understand security of supply. |