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
|
Image
|
|
Current Storage Positions
Overview
National hydro storage increased slightly last week to 102% of the historic mean for this time of year. Total demand increased on the previous week with continued cold weather.
Last week saw some significant wind generation volatility, particularly on 3 July, highlighting the importance of flexible resources and tools in the market. This is discussed further in the insight on the next page.
Security of Supply and Capacity
Energy
New Zealand hydro storage increased to 102% of the historic mean this week from 101% the week prior. South Island hydro storage remained at 95% while North Island storage increased from 162% to 171% last week.
Capacity
Capacity margins were still relatively healthy last week, the tightest peak being the evening of 1 July when residual generation was down at 549 MW. This coincided with cold evening temperatures and low wind generation across the motu. The N-1-G margins in the NZGB forecast are mostly healthy through to the end of August, with moderate margins in some days next week. 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 was 821 GWh, a 14 GWh increase from the week prior. The highest demand peak was 6,383 MW, which occurred at 6:00pm on Wednesday 2 July, coinciding with cooler temperatures. Load is expected to increase further in July and August, in line with typical winter demand.
Thursday 3 July observed an unusual load profile with the typical midday trough not eventuating, and demand remaining relatively flat from morning to afternoon due to a combination of wind and rainy weather.
Weekly Prices
The average wholesale electricity spot price at Ōtāhuhu last week decreased to $81/MWh from $91/MWh the week prior. Wholesale prices peaked at 1:30pm on Thursday 3 July with higher than usual midday demand and declining wind generation, reaching $329/MWh at Ōtāhuhu.
Generation Mix
Hydro generation picked up last week to 63% of the mix, from 56% the week prior, supported by recent inflows. As expected, thermal generation trended downwards as prices decreased and hydro storage picked up, contributing only 6% of the generation mix compared to 9% the week before. Geothermal contributed 23% of the generation mix and wind generation was slightly below average at 7% of the mix.
HVDC
HVDC flow last week was net northward, though southward flow dominated the weekend with low North Island demand. In total, 31 GWh was sent north and 15 GWh was sent south.