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 remains above average, with levels at 130% of the historic mean for this time of year. North Island storage continues to be high at 155% of the historic mean, while South Island storage is at 128% of the mean.
In this week's insight we go over price separation which was caused by a spring washer effect in the lower South Island.
Security of Supply and Capacity
Energy
National hydro storage has increased to 130% of historic mean at the end of last week from 125% the week prior. South Island storage has increased from 123% to 128% and North Island storage decreased from 159% to 155%.
Capacity
Residuals were lower than usual during morning and evening peaks most of the last week. The lowest residual of 507 MW occurred during the evening of Wednesday 24th June.
The N-1-G margins in the NZGB forecast show tighter spots appearing as we are now in winter; we recommend the industry watch these closely. 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 was high for this time of year at 842 GWh as shown on the top graph of page four. The highest demand peak of 6,572 MW occurred at 5:30pm on Friday 26th June, coinciding with a large southerly moving across the country.
Weekly Prices
The average wholesale electricity spot price at Ōtāhuhu last week increased to $47/MWh from $37/MWh the week prior. Wholesale prices peaked at $144/MWh at Ōtāhuhu at 1:00 pm on Wednesday 24th June due to a tight offer stack.
Generation Mix
Wind generation returned to its annual average of 9%, down from 11% the week prior. Hydro generation contributed 63%, slightly above its yearly average of 60%. Thermal generation was 4% of the mix last week, just under its annual average of 5%. Geothermal generation decreased slightly to 22%.
HVDC
HVDC flows last week were predominantly northward with one brief period of southward flow during Saturday night. Overall, 138 GWh was transferred north, while 2 GWh was transferred south during the week.
Consultations and Engagement
Security of Supply Annual Assessment (SOSA)
Today we have published our Security of Supply Annual Assessment 2026 (SOSA 2026). The annual assessment is used by market participants, policy makers and other stakeholders to inform risk management and investment decisions,
including about the development of new generation and transmission infrastructure.
System Operator Strategy
Our Phase 2 Consultation for the development of a new System Operator Strategy is open. Responses are due by Friday 24 July 2026. The draft Strategy sets out our proposed direction for how the System Operator service will need to evolve over the next ten years to support a secure, reliable and efficient power system.