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
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MO Latest Update.pdf
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Current Storage Positions
Security of Supply and Capacity
Energy
There was very little change in hydro storage levels last week and they remain at average levels after the large increase the week prior. National hydro storage increased slightly to 102% of the historic mean, up from 100% the week prior. South Island storage increased to 100%, up from 98%, while North Island storage increased from 126% to 127%.
Capacity
Capacity margins remained healthy last week, despite reduced thermal unit commitment following the increase in hydro storage levels. The lowest residual point of 779 MW was on Monday evening.
Looking forward, a customer advice notice (CAN) has been issued for a potential negative generation balance on Monday 29 April. The N-1-G margin when the CAN was issued was -20 MW, but it has since fallen further to -54 MW. There are also other days throughout May with low but positive N-1-G margins (less than 200 MW). We recommend that generators consider rescheduling outages to avoid these days and avoid scheduling any further outages that may reduce generation
margins. The latest NZGB report is available on the NZGB website.
Electricity Market Commentary
Weekly Demand
Total demand decreased by 2 GWh to 746 GWh last week, slightly higher than at this time of year over the last three years. Demand peaked at 5,471 MW on the evening of Tuesday 16 April.
Weekly Prices
The average wholesale energy price at Otahuhu last week dropped to $200/MWh from $223/MWh the week prior. Wholesale prices peaked at $578/MWh at Otahuhu on Saturday morning at 11:30AM during the planned outage of HVDC pole 3. North Island prices were high during the pole 3 outage because of the cost of procuring North Island fast instantaneous reserves (FIR) to cover the risk of a sudden failure of pole 2.
Generation Mix
The renewable percentage of the generation mix increased to 88% last week; with an increase in wind generation from 7.5% to 9%, and hydro generation from 57% to 58%. Thermal generation decreased from 13% to 10% of the mix, dropping below the past year's average thermal contribution.
HVDC
HVDC flows were northward for all trading periods last week with increased South Island hydro generation and reduced North Island thermal generation since the rain event the week before last. There were brief moments of southward transfer during the early hours of Saturday morning but all trading periods had net northward transfer.
Annual Industry Exercise
The Electricity Authority and Transpower are planning an industry exercise of a major power system event over two days on 1 and 8 May 2024.
Wednesday 1 May - for control room operators
This day will be led by the system operator to test grid emergency processes and interactions between the system operator and generators, lines companies and direct connect industrial customers.
Wednesday 8 May - for digital communications/social media/customer leads
This day will be led by the Electricity Authority alongside Transpower's communication team and will test communications and interactions from Transpower out through lines companies to retailers and end consumers. More information is available on our website.