Market Operations Weekly Report

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].

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More info on security of supply and capacity

Current Storage Positions

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Security of Supply and Capacity

Energy

Above average hydro inflows persisted in the North Island last week but, despite this, North Island hydro storage dropped from 72% to 70% of the historic mean for the time of year. South Island storage decreased from 77% to 74% of average with continued below average inflows. National hydro storage declined further to 74% of the historic mean for this time of year. Based on historic hydro storage data, current national hydro storage is sitting among the five lowest storage levels for this time of year since 1933.

The June Electricity Risk Curves have been published and show an increased energy security of supply risk for the remainder of 2024 and 2025.

Capacity

Margins were healthy last week, with all residuals above 1,000 MW as a result of high thermal unit commitment. NZGB N-1-G margins remain above 200 MW until July 12. For the rest of July, there are potential shortfalls appearing, including on 19 July for which a NZGB Customer Advice Notice (CAN) was issued. This is due to a combination of high demand seen for the same period last year and the extension of some generation outages. We recommend that participants consider the flexibility of planned outages and whether the start/end time of the outages can be rescheduled away from the peaks. We also recommend avoiding scheduling further outages during this period that may reduce generation margins. The latest NZGB report is available on the NZGB website

Electricity Market Commentary

Weekly Demand

Total demand increased marginally last week to 819 GWh (1% increase) but remained lower than this time during any of the last three years. Demand peaked at 6,413 MW on the evening of Wednesday 12 June. Tiwai has reduced their load further, with a 45 MW reduction.

Weekly Prices

The average wholesale energy price at Ōtāhuhu increased from $256/MWh to $265/MWh last week, in line with low hydro, slightly higher demand and high thermal unit commitment. The North Island and South Island reference prices are about double what they were this time last year when hydro storage was 126% of historic mean. Wholesale prices peaked at $370/MWh at Ōtāhuhu over the morning of Friday 21 June.

There were multiple periods of price separation throughout the week during periods of high southward power flow on the HVDC link. This resulted from low overnight demand and high North Island thermal generation.
 

Generation Mix

The renewable percentage of the generation mix decreased marginally by 2% to 78% last week. Wind and hydro generation remained steady at 8% and 51% of the mix respectively. The geothermal share of generation mix decreased from 21% to 20%. Thermal generators supplied 20% of demand, up from 18% the previous week.

HVDC

The majority of HVDC flow was southwards last week as a result of increased thermal generation in the North Island and decreased hydro generation in the South Island. 19 GWh was sent south and 13 GWh sent north. The northwards flow mostly occurred on weekdays when demand and hydro generation was highest.