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 has decreased from 105% to 103% of the historic mean for this time of year, contributing to the decrease in renewable generation to 90% of the weekly generation mix.
This week’s insight looks at load control and how it is influencing system behavior.
Security of Supply and Capacity
Energy
National hydro storage has decreased to 103% of the seasonal mean at the end of last week. South Island hydro storage decreased from 100% to 97% of the historic mean, and North Island storage remained at 173%.
Capacity
Residuals were healthy with the lowest residual of 475 MW occurring during the morning of Tuesday 17 March where low wind generation coincided with the morning demand peak.
The N-1-G margins in the NZGB forecast are healthy through to mid May. 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 increased from 740 GWh to 749 GWh for the week, and is in line with average demand at this time of year over the past three years. The highest demand peak of 5,368 MW occurred at 8:00am on Thursday 19 March.
Weekly Prices
The average wholesale electricity spot price at Ōtāhuhu last week was $198/MWh, increasing from $145/MWh the week prior. This is in line with declining hydro storage and wind generation, and the increase in thermal generation. Wholesale prices peaked at $328/MWh at Ōtāhuhu at 7:30pm on Wednesday 18 March, aligning again with a period of low wind generation.
Generation Mix
Wind generation was low last week, dropping to 5% of the mix. Hydro generation decreased from 62% to 61% of the mix. Thermal generation increased to its yearly average of 8% of the mix, despite only one Rankine unit being available for the week. Geothermal remained at 23% of the mix and solar contributed to 1% of the generation mix.
HVDC
HVDC flow last week was predominantly northward with the exception of some brief periods of overnight low southward flow. These periods coincided with periods of high wind generation and lower North Island demand. In total, 88 GWh was transferred north and just 6 GWh was transferred south.
Surveys and Engagement
We have opened our Annual System Operator Participant Survey to provide an opportunity for participants to set out their expectations and help us understand how we are performing the System Operator service. If you have not received the survey but would like to have your say, you can complete it here. The survey closes 17 April 2026.