Security of Supply
Following above average inflows in the South Island this week national hydro storage increased to 104% of average for the time of year (66% of full).
North Island storage decreased six percentage points to 65% of average for the time of year, while South Island storage increased by four percentage points to 109% of average.
National weekly demand rose 32 GWh on the previous week. The week's demand peaked at 7079 MW at 6pm on Monday evening, during a cold Southerly storm. This was the highest ever national peak demand.
Total generation was 904 GWh this week, with hydro generation making up 58%, and thermal 14% of the generation mix. Wind generation was high at 64 GWh, or 7% of the mix. This represents a 98% increase on last week.
The drop shown in geothermal generation for the morning of 14 August reflects lowered levels of generation from Mercury's Kawerau geothermal plant.
The average price at Haywards was $284/MWh, up 55% from $155/MWh last week.
Following last Monday's high demand event, prices rose to over $10,000/MWh between 19:00 and 21:00. This is in line with the scarcity pricing methodology set by the Electricty Authority in the event that there is insufficient generatrion to meet national demand.
From 18:00 to 19:00 on Monday 9 August prices reached around $2,700/MWh. This was reflective of the reserve deficits during these trading periods.
Note that all pricing discussed for Monday 9 August is currently interim, subject to pricing error and undesirable trading situation (UTS) claims.
HVDC transfer has remained Northward throughout the week.
Fact of the Week
Temperatures at many major centres on Monday 9 August were in the bottom one percent of temperatures over the evening peak since 1995.