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 104% of the historic mean for this time of year. North Island storage continues to be high at 163% of the historic mean, while South Island storage is at 99% of the mean.
Prior to last week we started a three-part deep dive series on the electricity sector's readiness for winter. Today's final edition looks at navigating operational risks in real-time.
Security of Supply and Capacity
Energy
National hydro storage has decreased to 104% of historic mean at the end of last week from 108% the week prior. South Island storage has decreased from 103% to 99% and North Island storage decreased from 185% to 163% with lower than average inflows for both islands last week.
Capacity
Residuals were lower than usual during morning and evening peaks most of the last week. The lowest residual of 363 MW occurred during the morning of Wednesday 27 May, which coincided with the highest demand peak of the week and low wind generation.
The N-1-G margins in the NZGB forecast remain healthy, but are trending downwards into winter with tighter spots appearing; 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 steady at 800 GWh for the week due to colder than average mornings. The highest demand peak of 6,134 MW occurred at 8:00am on Wednesday 27 May.
Weekly Prices
The average wholesale electricity spot price at Ōtāhuhu last week decreased to $98/MWh from $105/MWh the week prior. Wholesale prices peaked at $568/MWh at Ōtāhuhu at 7:30am on Wednesday 27 May, coinciding with high demand and low wind period.
Generation Mix
Wind generation remained the same at 6% of the generation mix last week, lower than its yearly average of 10%. Hydro generation was unchanged at 60% of the mix and thermal generation decreased from 8% to 6% of the generation mix. Geothermal generation increased from 22% to 25%, sitting above its annual average of 23%.
HVDC
HVDC flows last week were predominantly northward with very brief periods of southward flow overnight. Overall, 115 GWh was transferred north, while 10 GWh was transferred south during the week.
Consultations and Engagement
Draft Policy Statement
Consultation is open on our draft Policy Statement amendment proposal with submissions due by Thursday 4 June.
The Policy Statement describes the policies and processes the System Operator uses to meet the principal performance obligations (PPOs) in the Code for maintaining a stable and resilient power system in real-time, and to manage technical compliance and conflicts of interest.