Over the next 8-10 weeks we expect the risk of shortage due to hydro storage to remain low (though, in the unlikely event of multiple equipment failures the situation could deteriorate).
We are currently investigating the impact of restrictions to gas production at Pohokura on security of supply. At this time we do not believe it is necessary to modify the assumptions of the Hydro Risk Curves regarding thermal fuel availability, i.e. we would not expect there to be a physical limitation to thermal fuel that would constrain generation of electricity in an emergency situation. This view may change depending on the outcome of our ongoing investigation. We are also investigating the impact of future generator outages on the Hydro Risk Curves. We will provide further updates as more information becomes available.
The risk of shortage in the following 2-3 months is largely dependent on hydro catchment inflows. The Risk Meter is currently set to normal.
Current Situation
Aggregate New Zealand storage decreased over the last week and is at 35% of total storage, this is below the historical average (69% of average) for this time of the year.
Weekly hydro generation over the last 12 months has ranged between 48% and 71% of total generation. Last week hydro generation contributed 63% of total generation.
Hydro Storage Update
Controlled storage remains below average on the New Zealand and South Island hydro risk curves.
Inflows into Lake Taupo over the last week were lower than the historical average for the time of the year and there was a decrease in North Island storage.
South Island inflows were also lower than the historical average over the last week and storage levels have also decreased.
The spot price, based on available final and interim prices, has averaged $336 per MWh over the last two weeks, this is higher than prices experienced this time last year.
We periodically update the base HRC data curves and the Simulated Storage Trajectory Curves. The updated files for these are available on the Hydro Risk Curve page.
Data
Last Updated
Hydro Risk Curve Data File and Input Assumptions
12 October 2018
Simulated Storage Trajectories and Assumptions
25 September 2018
Next Report
The next scheduled weekly Security of Supply Report is due Tuesday 30 October 2018.