Multiple Frequency Keeping Trial

Multiple Frequency Keeping (MFK)

Multiple Frequency Keeping (MFK) is an ancillary service used by the System Operator to help maintain New Zealand’s electricity system frequency close to 50 Hz to support the secure and reliable operation of the power system. The MFK tool responds to changes between electricity supply and demand by directing selected providers to adjust their output accordingly to restore frequency close to 50 Hz. The national MFK band is currently set at 30 MW.

MFK Trial

New Zealand’s electricity system is changing rapidly as more renewable generation, particularly wind and solar, connects to the grid to meet growing demand. While these technologies play an important role in New Zealand’s energy future, they can also increase variability in the balance between electricity generation and demand, creating additional challenges for frequency management. 

Our recent analysis completed for the Electricity Authority indicates that the current MFK settings are becoming increasingly constrained during periods of rapid demand change and higher levels of intermittent generation. 

We will undertake a targeted three-month trial increasing the national MFK band from 30 MW to 50 MW during defined daytime operating hours. The trial will help assess whether a wider MFK band can improve frequency quality and support the reliable operation of New Zealand’s evolving power system. The trial will also inform future decisions on frequency keeping arrangements as part of the Authority’s development of a Frequency Management Strategy.

The System Operator recognises that increasing the MFK band may increase Frequency Keeping procurement costs. For that reason, this will be a time-limited and closely monitored trial, with defined operating hours and clear investigation and suspension triggers. Following the completion of the trial, the System Operator will review and publish a Summary Report, which will include proposed next steps.

More information

For further detail on why we will conduct the trial, refer to the MFK Trial Report below. If you have any questions on the MFK trial, please contact us at [email protected].