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
New Zealand hydro storage remains above average at 108% of the mean for this time of year, with above average inflows offset by above average hydro generation. There were some periods of very low prices, particularly during periods of high wind generation.
This week’s insight looks at the relationship between NIWA's Seasonal Climate Outlooks and quarterly hydro inflows.
Security of Supply and Capacity
Energy
National hydro storage increased slightly to 108% of the historic mean for this time of year. South Island hydro storage increased from 102% to 104%, while North Island storage decreased from 137% to 132%.
Capacity
While capacity residual margins were high for most of last week, residual dropped to 300 MW on the morning of Thursday 2 October. We continue to monitor capacity closely during the spring shoulder season despite decreasing demand. Outages, reduced thermal unit commitment, and the possibility of cold snaps or large swings in wind generation mean that capacity can be tight despite much lower peaks than in winter.
The N-1-G margins in the NZGB forecast are healthy through to the end of November. 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 last week remained steady at 780 GWh. The highest demand peak occurred at 8:00am on Thursday 2 October at 5,871 MW.
Weekly Prices
The average wholesale electricity spot price at Ōtāhuhu last week increased to $65/MWh from $35/MWh the week prior. Wholesale prices peaked at $413/MWh at Ōtāhuhu at 8:00am on Thursday 2 October, as high-priced gas peakers were required to start up to support high loads with low wind generation and little slow-start thermal generation online.
Generation Mix
Renewable generation contributed 96% of the generation mix last week. Hydro generation contributed 62%, well above the 52-week average of 56%. Wind generation decreased from 13% to 9% of the mix. Thermal generation decreased from 5% to only 3%. Geothermal contributed 24%.
HVDC
HVDC flow last week was predominantly northward, particularly on days with low wind generation. In total, 31 GWh was sent north and 5 GWh was sent south.
CACTIS Consultation Closed
Consultation on the proposed Connected Asset Commissioning, Testing and Information Standard (CACTIS) closed on 29 September. Submissions were received from 15 organisations. These have been published on our website here.
SOSFIP Consultation Open
Consultation on a draft amendment to the System Operator Forecasting and Information Policy (SOSFIP) is now open. The closing date for submissions is 5pm on Tuesday 4 November 2025, with cross-submissions due by 5pm on Tuesday 11 November 2025.