Summary
Security of Supply
National hydro storage increased this week to 125% of average for the time of year (76% of full). This was the result of above average inflows in the South Island.
North Island storage increased three percentage points to 83% of the historical average. South Island storage increased by 11 percentage points to 131% of the historical average.
Weekly Demand
National weekly demand increased 23 GWh (three percent) on the previous week to 785 GWh.
This week's peak was 6,492 MW and occurred at 18:30 on Monday 8 September 2021.
Generation Mix
Total generation was 821 GWh this week, with hydro making up 60%, and thermal 8% of the mix. Wind generation was high at 79 GWh, or 9.6% of the mix; up by 27 GWh from last week.
Weekly Prices
The average price at Haywards was $93/MWh, up 45% from $64/MWh last week.
Prices at Haywards peaked at $493/MWh on Wednesday morning, corresponding with high demand (the first evening of Alert Level 2 outside of Auckland) and moderate levels of wind generation.
This Friday inter-island price separation and high North island prices followed the unplanned outage of Pole 2 of the HVDC system from 07:30 to 13:00. The Pole 2 outage is believed to be related to very high winds driving the conductor too close to a tower located in the northern Canterbury region.
On Sunday there was intra-island price separation in the lower South Island. Transmission was constrained due to the potential loss of both the Clyde – Cromwell - Twizel circuits 1 and 2 being managed as a single event, due to a severe te uira (lightning) storm in the area.
HVDC
HVDC transfer has remained Northward throughout the week. HVDC transfer exceeded a 1,000 MW on Saturday evening.
Fact of the Week
In the German language, there is a word that refers to the fear of having inadequate sunshine or wind to maintain a viable supply of renewable energy: dunkelflaute. The dramatic connotation of the word may be lost a bit in translation, but essentially, dunkelflaute means “a dark lullˮ.
|
|
