Security of Supply and Capacity
Energy
Hydro storage sits at 147% of average for the time of year, a 2% decrease on the week prior. South Island storage is at 150% of the historic average, a minor decrease from the week prior as high hydro generation barely outpaced above average South Island inflows.
Huntly Unit 5 is still on outage until 20 November, and Nga Awa Purua (136 MW geothermal) is on outage as of 12 November until 3 December.
Capacity
Residual generation continues to be healthy as we move into the warmer and lighter season with lower demand. The NZGB report for November 2022, covering the next six months, is available on the NZGB website, and forecasts no shortfalls.
Electricity Market Commentary
Weekly Demand
Demand increased slightly on the previous week from 729GWh to 742GWh. Demand peaked 8am on Wednesday morning (9th November) at 5,337 MW. The evening peaks are starting to show the distinct summer pattern of two peaks, one when people get home, and one later as lighting load starts.
Weekly Prices
Wholesale prices increased from the previous week, up from $9/MWh to $50/MWh at Haywards as wind and run-of-river hydro generation decreased. Prices peaked at $384/MWh in the North Island at 8am on Wednesday coinciding with the peak load for the week and when the HVDC was setting the risk. North Island sustained reserve prices were $225/MW. Due to planned HVDC equipment outages, island price separation occurred several times during the week.
Last week saw the first trading period to use a Price-Responsive Schedule Short (PRSS) in its final pricing calculation as the system was on Stand Alone Dispatch (SAD) due to a brief market system outage. This is a feature of Real-Time Pricing (RTP) that provides price certainty.
Generation Mix
Similar to the week previous, a large portion of the week was spent with no thermal generation other than co-generation plant. Renewable contribution to the generation mix was even higher than the week prior at 97%, up one percentage point on last week's record.
Wind generation decreased from 8.7% to 6.7% of the energy mix, while hydro generation increased to comprise 72% of the weekly generation mix.
Low thermal generation at just 1% of the generation mix was due to Huntly Unit 5 still being on an outage until 20 November and, again, only one Rankine unit running for part of the week.
HVDC
The HVDC was in high north flow all week reflecting the high hydrological position in the South Island.
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