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Current Status as at: 12 May 2019


As mentioned in previous weeks, national storage remains above average for this time of year, which indicates a low risk of shortage this winter. While there was some rainfall in the Taupo region over the weekend, North Island storage remains below average for this time of year at 58% of average. South Island storage decreased slightly over the last week, but remains above average at 113%.
We have published the next edition of the HRC 101 series. This week we review all the previously discussed input assumptions and examine what impact they can have on the HRCs.

The review of the Security of Supply Forecasting and Information Policy is almost complete. The policy has been through the governance process at the Electricity Authority. We are currently working with the Authority to finalise the changes to the policy and draft a decision paper based on the policy approved by the Authority’s board. This process is expected to be completed in the week beginning 27 May, with the publication of the decision paper and a gazette notice.

Current Situation 

Aggregate New Zealand storage decreased over the last week and is at 77% of total storage, this is above the historical average (109% of average) for this time of the year.

Weekly hydro generation over the last 12 months has ranged between 54% and 66% of total generation. Last week hydro generation contributed 59% of total generation.

Hydro Storage Update

Controlled storage remains above 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 slightly higher than the historical average over the last week however storage levels have marginally decreased.
View the latest Hydro Risk Curves  »
Read more about Hydro Storage  »

Generation Mix Update

Generation from non hydro sources are expected to remain at current levels.
Read more about Generation Mix  »

Demand Update

New Zealand electricity usage is about average for this time of the year.
Read more about Demand »

Transmission Update

There was a net HVDC energy transfer to the North Island of 86 GWh last week. 
Read more about Transmission »

Wholesale Prices Update

The spot price, based on available final and interim prices, has averaged $108 per MWh over the last two weeks, this is higher than prices experienced this time last year.
Read more about Wholesale Pricing »

Data Updates

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 30 April 2019
Simulated Storage Trajectories and Assumptions 30 April 2019

Next Report

The next scheduled weekly Security of Supply Report is due Tuesday 21 May 2019.

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