Security of Supply
National hydro storage has decreased by four percentage points to 75% of average for this time of year, dropping further below the 90th percentile of its
Despite some inflows over the past fortnight, North Island storage has decreased by 14% to 72% of average for this time of year. South Island storage has decreased by 3.5% to 75% of average for this time of year.
The Maui outage continues until 08 June and Methanex's consumption remains reduced at around 60 TJs per day.
Demand increased slightly from the week prior to 804 GWh. This was the highest demand of the year to date. The ramp up in demand is consistent with the winter seasonality patterns of previous years.
Demand peaked at 6,205 MW on Thursday 26 May at 6:00pm, during a period of low temperatures. This was the highest peak demand observed this year to date.
National generation was 834 GWh this week with 77% of the generation mix contributed by renewable generation. Reflecting current hydrology, hydro generation comprised 54% of the total generation mix. Wind generation decreased from the week prior to comprise 4.9% of the generation mix. Wind generation was stronger towards the start of the week.
The average price at Haywards was $217/MWh, a 10% increase from $197 MWh the week before. Prices fell to $0.03/MWh in the early hours of Monday 23 May. This coincided with low demand and moderate wind generation. Prices peaked at $465/MWh on Tuesday 24 May at 7:30am during a time of high demand, low wind generation and a Huntly U5 generator trip.
This week there were periods of southward HVDC flow each night due to a combination of high wind, low demand periods and higher North Island baseload thermal generation.
2022 Security of Supply Annual Assessment Consultation
The draft 2022 Security of Supply Annual Assessment (2022 SOSA) is currently out for consultation and is available here on the Transpower website. Consultation closes at 5pm on 08 June.
Seven of the top 10 highest demand trading periods this year (to date) occurred this week.