Email not displaying correctly? View this email in your browser
Weekly Update sent on 28 September 2021
Hi <<First Name>>
Latest Full report available here


Security of Supply

Hydro storage continues to climb and is 136% of average for the time of year, this is 211 GWh above the 90th percentile. We are at time of year when storage is typically at its lowest and starts to climb off the back of dropping demand and historically strong spring inflows. Snow storage in the Waitaki is reported at 129% for the time if year, typically this starts to melt from mid-October. Of note, Manapouri is operating above its maximum range indicating spill.

Weekly Demand

The return of daylight savings is a signal spring is here. Longer and warmer days are seeing demand trend downward. Demand fell 5.8% on the week prior to 758GWh.

Generation Mix

As expected, with high levels of storage and inflows, hydro continues to dominate the generaiton mix. The mix comprised of 61.3% hydro, 6.6% thermal, and 8.6% wind for the week. The renewable share of generation for the week totalled 90.1%.

Weekly Prices

Low demand and strong hydro storage have seen prices drop $50/MWh to $47MWh. Periods of $0.01/MWh in Southland are the result of a Manapouri above 100% of full combined with lighting and outages effecting transmission capacity out of Southland.


Strong hydro storage continued to push the HVDC transfer strongly northwards. Regularly transferring above 850MW when North Island wind generation was low.

Invitation to Tender for the Supply of Ancillary Services from 1 December 2021

In 2021, the System Operator are inviting tenders for Back-Up Single Provider Frequency Keeping, Black Start (North Island only), Instantaneous Reserves and Multiple Provider Frequency Keeping.

All services will be procured on a two year term from 1 December 2021 to 30 November 2023.

The tender information can be found on the Transpower website here.

Fact of the Week

The largest single power station in the world is the Three Gorges Dam. Located in China with a capacity of 22,500MW it could meet NZ’s record peak demand 3 times over!


Go to Security of Supply web page

Next Report

The next scheduled Market Operations weekly report is due Tuesday 5 October 2021.

Transpower Website

If you have any queries, please email
You can forward to a friendunsubscribe from this list or update your subscription preferences.