Electricity Demand and Supply Generation Scenarios 2016

The Electricity Demand and Supply Generation Scenarios (2016) are published below.

EDGS Scenario and Results Summary report provides an overview of the five modelled scenarios and key results.


EDGS results tool provides interactive charts to help compare the assumptions and results across time and between scenarios


Assumptions for each modelled scenario are provided in the Assumptions Summary. New and existing electricity generation plant capital and operational costs are provided in the Generation Cost Assumptions file.

Results files provide yearly figures (2016 – 2050), with a summary of results for all five scenarios included in the Scenario summary file and more detailed scenario specific results provided in the named scenarios results files.


Energy Sector Modelling Technical Guide provides a detailed guide to the modelling methodology employed to produce the EDGS scenarios


The Interactive electricity generation cost model is published by MBIE. This interactive tool illustrates the LRMC of potential new generation capacity that could be built in the New Zealand electricity market under different assumptions.

Draft EDGS Consultation Response

The Ministry identified three high priority issues from the submissions and cross submissions on the draft EDGS published in April 2015 that had clear consensus among stakeholders and/or the impact was material - see the Response to submissions [PDF 202KB]. The actions MBIE has taken on these are summarised below:

Verifying peak demand forecasting.

The Ministry commissioned a review by NZIER of Transpower’s peak demand forecasting model. After amendment by Transpower the forecast model was judged fit-for-purpose for use in the EDGS.

The Ministry investigated alternative models for forecasting peak demand but found no suitable models. More complex half hourly peak demand models have been scoped; however the investment to build more detailed peak modelling has not been undertaken at the time of publishing the Electricity Demand and Supply Scenarios in 2016. The Ministry now has the ability to run the Transpower ensemble model in-house and will monitor the model diagnostics.

Residential demand forecasts

MBIE has further explored many different explanatory variables in order to better explain recent trends. Understanding the drivers influencing residential demand changes is complex and there are limitations to the available explanatory data. This is an area MBIE will continue to explore. However, the residential model has been revised to take into account the recent per capita demand reductions, by including lagged terms, resulting in a lower residential demand forecasts. Flat per household residential demand has been assumed in one of the scenarios modelled in the 2016 EDGS scenarios.

Adding a disruptive technology scenario

MBIE has modelled a scenario which assumes high uptake of new technology that could be disruptive to the electricity grid. This includes high uptake of technologies that could affect the grid such as solar with batteries and electric vehicles.

Detailed hourly solar supply and battery operation has been modelled in conjunction with solar and solar with battery economics. This is used to inform both the uptake of household and commercial solar and solar with batteries and the impacts on electricity energy and peak demand

Review the scenario design

MBIE has reduced the number of scenarios from eight to five. The five scenarios have been developed to explore a plausible range of uncertainty about the future electricity system. The five scenarios are described below:

The Mixed Renewables scenario has a mixture of geothermal and wind plant built, starting in the early 2020’s. This scenario assumes an average of 1% annual electricity demand growth, reflecting moderate GDP and population growth, and current views on relative technology cost and expected fuel and carbon prices.

The High Grid scenario assumes higher GDP and population growth rates leading to higher electricity demand across all sectors; with 1.3% per year growth in grid connected electricity demand. Higher gas exploration effort results in higher domestic gas supply with a flat wholesale gas price of around $6/PJ to 2040.

The Global Low Carbon scenario assumes a high carbon price and lower cost renewable technology (wind and solar) which leads to more renewable build. This scenario assumes high uptake of petrol hybrid vehicles and solar PV systems, and flat electricity demand per household due to efficiency measures.

In the Disruptive scenario a reduction in technology costs leads to high uptake of Solar PV with batteries and electric vehicles. Both total electricity demand and grid connected demand increases as the additional electric vehicle demand is only partially offset by solar generation. Peak and off peak retail electricity price signals lead to flattening of demand, with a lower peak demand through battery load shifting and off peak EV charging.

In the Tiwai Off scenario Tiwai shuts at the start of 2018 and lower GDP growth leads to lower electricity demand across all sectors, averaging 0.4% p.a.