Security of Supply
National hydro storage has increased by two percent to 79% of average for this time of year, remaining just below the 90th percentile of its historical range. This is due to an inflow event, which was more impactful for both the Manapouri and Te Anau catchments.
North Island storage has increased by 5% to 86% of average for this time of year. South Island storage has increased by 1.9% to 79% of average for this time of year.
Aligned with the start of the Maui outage we have observed Methanex curtailing their demand, which is releasing gas to other industries.
Demand decreased slightly from the week before to 766 GWh. The national demand profiles remained relatively consistent from Monday to Friday with an anticipated drop for the weekend.
Demand peaked at 6,047 MW on Friday at 6:00pm. This is a two percent decrease from the previous week's peak of 6,164 MW.
Despite the slight decline in demand from the previous week, we experienced the first winter storm for the year, which led to four relatively small loss of supply events on Friday the 20th.
National generation was 797 GWh this week. In reflection of current hydrology, hydro generation comprised 51.6% of the total generation mix (a 2% reduction on the week prior). Despite TCC having returned to the market since Tuesday the 17th, thermal generation comprised 16.4% of the generation mix (a 1% reduction on the week prior). Wind generation increased significantly from the week earlier to comprise 10% of the generation mix. Wind generation peaked at 728 MW on Thursday the 19th at 5:30pm.
Prices continued to hover around the $200 mark, reflecting the below average hydrology, and upward price pressure on thermal fuels including carbon.
The average price at Haywards was $199/MWh, an 11% decrease from $224 MWh the week before. Prices fell drastically to $5/MWh in the early hours of Friday the 20th as a result of 659 MW of wind generation during the overnight demand trough.
This week we saw daily periods of southward HVDC flow through the night due to a combination of high wind, low demand periods and higher North Island baseload thermal generation. The highest northward flow was 570.
2022 Security of Supply Annual Assessment Consultation
The draft 2022 Security of Supply Annual Assessment (2022 SOSA) is currently out for consultation available here on the Transpower website. Consultation on the 2022 SOSA closes at 5pm on 08 June.
2022 Ancillary Services Procurement Plan
The new 2022 Ancillary Services Procurement Plan (effective 03 May 2022) is now live on the Electricity Authority website here. The new procurement plan enables BESS to provide injectable reserves in the instantaneous reserves market.