1. Overview

TIMES-NZ produces a model solution that meets projected energy demand while minimising costs. To effectively determine the cost of an additional unit of generated electricity, the model uses detailed costs and technical parameters of:

• existing generation assets

• potential future generation assets

• peak load requirements

• transmission and distribution costs and losses

• current and potential future storage methods

• winter energy and capacity margin requirements

• renewable availability (i.e. what times of year and day solar and wind are available)

1.1. Scenario adjustments

The different TIMES-NZ scenarios, Steady and Shift, are structured on four different critical uncertainties. For electricity supply, we adjust costs and availabilities of future generation technology to align with these uncertainties. Current scenario adjustments include:

• In Steady, we use the MBIE Reference generation stack scenario data for potential future plants, with costs falling over time in line with the NREL Conservative scenario. For battery technology costs, we use CSIRO’s “Current policies” scenario.

• In Shift, with anticipated greater investment in renewable technology and faster technology development, we instead use the MBIE Innovation generation stack scenario, with the faster cost declines of the NREL Moderate scenario. For battery technology costs, we CSIRO’s “NZE by 2050” scenario. Other assumptions will apply no matter the scenario, unless specified otherwise. Further details on these scenario adjustments can be found in the relevant sections of this document.