Our Market Operations Weekly Report contains the latest information about the electricity market, including security of supply, wholesale price trends and system capacity.
It is published every Tuesday. Click here to receive the report via email every week.
If you have any comments or questions please contact the Market Operations Team at [email protected].
Latest Report / More Information
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Current Storage Positions
Overview
National hydro storage has declined to below the 90th percentile from 130% to 121% of the historic mean for this time of year National hydro storage remained below the 90th percentile last week, decreasing from 121% to 119% of the historic mean for this time of year but remains healthy and above average. Solar generation broke yet another record on Sunday 18
October.
In this week's insight we look at the impact of El Niño on national hydro storage.
Security of Supply and Capacity
Energy
National hydro storage decreased to 119% of the historic mean from 121% the week prior reflecting lower hydro generation last week. South Island storage decreased from 129% to 126% while North Island storage increased from 75% to 76%.
Capacity
Residual generation was healthy last week. The lowest residual was 602 MW in the evening of Monday 12 October.
The N-1-G margins in the NZGB forecast are at healthy levels through to mid December. Within seven days we monitor these more closely through the market schedules. The latest NZGB report is available on the NZGB website.
Electricity Market Commentary
Weekly Demand
Total demand increased last week to 764 GWh from 755 GWh the week prior. The highest demand peak occurred at 8:00 am on Friday 16 October at 5,849 MW during a particularly cold snap.
Weekly Prices
Wholesale electricity spot prices increased last week with the average Ōtāhuhu price up at $60/MWh from $35/MWh the previous week. Prices peaked at $299/MWh at 8:00 pm on Monday 5 October.
Periods of inter-island energy price separation occurred throughout the week during periods of high HVDC northward transfer.
Generation Mix
Wind generation increased last week from 7.5% to 11.5% of the mix offsetting hydro which dropped from 65% to 60%. The remaining mix stayed consistent last week from the week prior. Solar and wind generation were both above average at 2.9% and 11.5% of the mix respectively while thermal and geothermal were both below average at 1.8% and 22.2% of the mix.
HVDC
HVDC flows last week were entirely northward consistent with recent transfer patterns. In total 113.5 GWh was transferred north.
Consultations
We are consulting on the TSO:DSO coordination: operations requirements paper. Please send your feedback by email to [email protected] by 5pm on Friday 6 November 2026.
Ancillary Services Tender
The 2026 Ancillary Services tender is now open. The System Operator invites tenders for the provision of Over-Frequency Reserve and South Island Black Start services.
Tender responses are due by 5:00 pm on 3 November 2026 via the System Operator portal here. Successful respondents will be offered contracts commencing 1 January 2027. Any questions about the tender process can be sent to [email protected].