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 increased to 149% of the historic mean last week, a record for this time of year, and is now at nominal maximum capacity.
This week’s insight looks at the increasing share of renewable generation in Aotearoa's electricity supply mix.
Security of Supply and Capacity
Energy
National hydro storage increased by seven percentage points to 149% of the historic mean, the highest level on record for this time of year. South Island hydro storage increased from 143% to 150% of the historic mean while North Island storage decreased slightly from 138% to 137%.
Capacity
Residuals were mostly healthy with at least 500 MW of residual across all peaks last week. The lowest residual period for the week was the Tuesday morning peak at 588 MW.
The N-1-G margins in the NZGB forecast are healthy through to late January. 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 750 GWh the week prior to 762 GWh, and was higher than weekly demand levels observed at this time of year over the past three years. This is likely attributable to the hotter than usual weather. The highest demand peak of 5,404 MW occurred at 5:30 pm on Thursday 27 November.
Weekly Prices
Average wholesale spot prices decreased last week in line with high hydro storage and inflows. The average wholesale electricity spot price at Ōtāhuhu last week was $54/MWh, down from $57/MWh the week prior. Wholesale prices peaked at $381/MWh at Ōtāhuhu at 3:00 pm on Tuesday 18 November, with some binding transmission constraints in the North Island due to transmission outages.
Generation Mix
Wind generation increased to 10% of the generation mix, above its average contribution of 9%. Hydro generation remained well above average at 69% of the mix. Thermal generation remained very low at just 1.1% of the mix, with co-generation also at 1.1% and solar generation exceeding both at 1.2%. The
geothermal share remained at 17% of the mix — well below its average contribution of 23% — with multiple geothermal units on planned outage during the week. Total renewable contribution to the mix was 98%, the eighth consecutive week of at least 97% renewable generation.
HVDC
HVDC flow last week was entirely northward with high hydro generation, decreased geothermal generation, and higher demand in the North Island. In total, 90 GWh was transferred north. AC asset outages have reduced physical capacity, causing the northward limit to constrain flows at times.