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].

Latest Report


Previous Reports

Current Storage Positions


Security of Supply and Capacity


National hydro storage continued to trend towards average this week and now sits at 101% of the historic mean, down slightly from 102% the previous week. South Island storage is at 96% of the historic mean, down from 97%, and North Island storage dropped from 158% to 154% of the mean.


Capacity margins were healthy last week with the lowest residual point being 749MW on Friday evening.

Forecast N-1-G margins are healthy throughout the forecast horizon to late March. The HVDC outages running from 21 February - 14 March are considered in the margin calculation. The lowest N-1-G margin during the forecast period is 430 MW on 21 March. However, we issued a CAN calling for additional South Island reserve offers on 24 & 25 February during the upcoming planned bipole outage. The latest NZGB report is available on the NZGB website

Electricity Market Commentary

Weekly Demand

Demand remains mild as is typical in summer. Last week demand increased from 740 GWh the week prior to 747 GWh. Demand peaked at 5,350 MW on the evening of Thursday 15 February.

Weekly Prices

Prices last week appeared to be more stable than the week prior. However, the average wholesale price at Otahuhu last week was $177/MWh, up from $129/MWh the week prior. The Otahuhu price peaked at $275/MWh on Friday 16 February at 15:30.

The increased average wholesale price last week was in line with thermal contribution to the generation mix rising as hydro and wind generation eased off.

Generation Mix

The renewable percentage of the generation mix dropped to 88% from 91%, which is on par with the previous 52 week average. Wind generation fell from 11% of the mix to 8.5%, and hydro decreased by a single percentage point to 60% of the generation mix. This was almost entirely replaced by thermal generation which increased to 10% of the mix from 7% the week prior.


All daytime HVDC flows last week were northward. There was southward flow on a few nights, coinciding with periods of low demand and high North Island wind generation.

The upcoming HVDC outages are:
Pole 3 outage: 21 February - 24 February
Bipole outage: 24 February - 25 February
Pole 2 outage: 25 February - 14 March
For further details see the Customer Advice Notice.

SOSA Reference Case and Sensitivities Consultation

We recently published our responses to feedback received on the SOSA Reference Case and Sensitivities Consultation. This can be found here

SOROP Consultation

Transpower is seeking views from the electricity industry on proposed changes to the System Operator Rolling Outage Plan (SOROP). The consultation started on 7 February and runs until 6 March. There is then a two-week period for cross submissions until 20 March. Please see our website for further details.

The SOROP is one of Transpower’s key security of supply planning and policy documents in it's system operator role. The review is required as the current version of the SOROP has been in place since 2016 and security of supply risks are changing.