Annual Assessment Results

This year we have prepared a web-application to view different combinations of sensitivities on the three core scenarios presented in the Security of Supply Annual Assessment 2019 report


The three scenarios are:

  • Low demand:  this scenario represents a world where New Zealand’s carbon emissions are not addressed through the electrification of transport and industry. As a result, electricity demand growth is similar to what has been observed in recent years. This scenario assumes a demand forecast that is similar to forecasts used in previous annual assessments where significant electrification of transportation and industry was not accounted for and assumes underlying wholesale market demand for electricity growth averages 0.6-0.7% across the decade.
  • Medium demand: this scenario uses a demand forecast that broadly aligns with the base case scenario in Te Mauri Hiko. The Te Mauri Hiko base case scenario involves a coordinated, but moderate response to climate change—increasing electricity growth is observed as regulation and market incentives lead to the electrification of transport and process heat. This effect starts slowly but grows over time and this scenario assumes underlying wholesale market demand for electricity grows at an average of 1.0% per year. 
  • Thermal constraints: this scenario represents a future where gas-fired thermal generation growth is limited. It uses the same demand outlook as the medium demand scenario above but assumes 500 MW of new gas-fired thermal generation is unavailable. This could occur if less new thermal generation is built, or, equivalently, existing thermal generation is reduced by 500 MW.

The sensitivities are shown in the table below:

Sensitivity Rationale Assumptions
High Demand This sensitivity explores the situation where demand growth is higher than anticipated. Follows the Vibrant Haven Te Mauri Hiko demand forecast, equivalent to an average growth rate of 2-3% annual growth rate (growth increases rapidly near the end of the 2020s.
Solar Generation This sensitivity explores the impact that different degrees of solar uptake could have on future demand and generation. Solar energy generation is related to the demand forecast used, and the impact of solar on capacity is approximated to battery storage at peak. Solar generation is divided into 4 sensitivities with the following annual increases – very high solar, high solar, medium solar, and low solar.
Tiwai Early Exit This sensitivity explores the situation where the NZAS aluminium smelter starts reducing its output from 2025 and closes at the end of 2026. It is assumed the Rankine units at Huntly would shut at the same time. NZAS reduces load in stages beginning in 2025 until it reaches 0 GWh of demand in 2027.  Assumed to consume 616 MW in 2024, 411 MW in 2025 and 205 MW in 2026. Generation at the Huntly Rankines stops in 2025.
Thermal Decommissioning This sensitivity explores the situation where one of the two Combined Cycle Gas Turbines shuts down in 2022. Generation from one of the Combined Cycle Gas Turbines stops at the beginning of 2022 (equivalent to 360 MW of generation).
De-rated Generation This sensitivity explores the impact of a reduction in electricity supply. This sensitivity is designed to indirectly account for internal and external influences that may reduce the output of electricity generation. External influences include effects such as reduction in geothermal field pressure, systemic changes to inflow patterns, etc.  Internal influences include effects such as statistical errors in historical generation data and forecast errors for new generation. In the calculation of energy margins, all non-thermal generation energy contribution is reduced by 5%. In the calculation of capacity margins, all non-thermal generation capacity factors are reduced by 5%.
Delayed Build Times This sensitivity explores the situation where the commissioning date for new generation is delayed by 1 year. Commissioning dates for all new generation is delayed by 1 year.

 

For more information, refer to Appendix 2: Sensitivities in the Security of Supply Annual Assessment 2019 report.

 

Glossary:

LD

Low Demand Scenario

MD

Medium Demand Scenario

TC

Thermal Constrained Scenario

HD

High Demand Sensitivity

E+C

Existing and committed (consented and proceeding)

Coh/Amcc

Consented and on hold/awaiting market conditions to change

Coh/Amcc/RcR

Consented, and on hold/awaiting market conditions to change. But for this project the consent requires revision or reconsent.

NC

Not consented, but consent is likely to be sought within the next 2 years

Please note that this web-application may take longer to load when run in Internet Explorer. We recommend using Chrome or Firefox to avoid this. 

Annual Assessment Chart

Filters

Scenarios:





Solar:





Sensitivities: