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 continued its decline last week, falling to 114% of the seasonal average from 119% the previous week. Solar generation made another record this week with a 4% contribution to the generation mix, higher than any previous week.
In this week's insight we look at the impact of small distributed solar generation (<10 MW) on daily demand profiles.
Security of Supply and Capacity
Energy
Below average inflows last week meant that National hydro storage decreased to 114% of the seasonal average from 119% the week prior. This was despite lower than average hydro generation and relatively low demand. South Island storage decreased from 126% to 120% while North Island storage increased slightly from 76% to 77%.
Capacity
Residual generation was healthy last week. The lowest residual was 817 MW on the morning of Monday 19 October.
The N-1-G margins in the NZGB forecast are at healthy levels through to late 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 decreased last week to 733 GWh from 764 GWh the week prior. The highest demand peak occurred at 7:30 am on Monday 19 October at 5,520 MW with cooler temperatures in parts of the country.
Weekly Prices
Wholesale electricity spot prices decreased last week with the average Ōtāhuhu price down to $66/MWh from $75/MWh the previous week. The Ōtāhuhu price peaked at $312/MWh at 9:00 pm on Wednesday 21 October, with constrained
HVDC northward flow requiring higher priced North Island hydro offers to be cleared.
Periods of inter-island energy price separation occurred throughout the week during periods of high HVDC northward transfer, with outages of lower North Island grid equipment lowering the northward transfer limit.
Generation Mix
Hydro generation was below average last week at 57%, down from 60% the week prior. Solar generation contributed a new record share of 4%. The geothermal share increased to 25% last week from 22% the week prior. Wind, thermal and cogeneration were steady at 11%, 2% and 1% of the mix respectively.
HVDC
HVDC flows last week were almost entirely northward, consistent with above average South Island hydro storage. Northward transfer decreased over the weekend with lower demand and high North Island wind generation. In total 101 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].