Review of 2021 dry year event

The ‘dry year problem’ is that New Zealand’s hydro lakes sometimes don’t receive enough rainfall or snowmelt. The level of hydro storage runs low decreasing the capacity for generation. When this occurs some form of back-up generation is needed. This is currently provided by thermal fuel generation.

We contracted MartinJenkins to conduct an independent review of the 2021 dry year event to learn from the management of fuel supplies and performance of the system operator and Electricity Authority. The review made several findings and recommendations. We released this review for industry feedback and received the below submissions.

As a result of this review, we made changes to our communications with Transpower. The system operator made changes to their communications with us, and updated their security of supply forecasting and information policy and emergency management policy. They also implemented some of the additional activities recommended, such as regular industry forums.

In December 2021, we sought industry feedback on the independent review of the 2021 dry year event. To follow is our consultation paper which includes MartinJenkins report in Appendix A.

In early 2021, hydro lake levels began to decrease significantly changing the security of electricity supply. In March/April, the perceived risk to supply had reached such a level that generators began striking deals to divert natural gas from industrial users to power generation. In May the rain came, boosting hydro lake levels well out of any danger zone and resolving security of supply.

We contracted an independent review of the 2021 dry year event in order to identify and act on the lessons learned.