With regard to the demand forecasts, the Commission reviewed the underlying model and therefore, most of the feedback sought in the 2009 GPA consultation paper was around input assumptions and methodology of the demand forecasts, as changes in the population growth forecasts produced by Statistics New Zealand appeared likely to impact significantly on the Commission's forecasts. The Commission considered it prudent to have its methodology peer reviewed before publishing an updated version. Therefore, in preparing the 2009 GPA scenarios, the Commission used the 2008 demand forecasts.

The Commission expected stakeholders and Transpower to use the GPA presented here as an appropriate starting point for their own analyses.

As part of its process to seek feedback from participants about the development of the GPA, the Commission held a workshop on 16 October 2009 in Wellington:

James Cook Hotel Grand Chancellor
147 the Terrace
Wellington

The workshop was of both a general and a technical nature and provided stakeholders with an opportunity to hear directly from Commission staff and to ask questions about various aspects of the GPA.

Comments on the draft 2009 GPAs were sought by 5 pm on Friday 6 November 2009, The Commission received 11 submissions.

GPA Input Files

Following the 16 October 2009 workshop a request was made for the input data used in the GEM runs.

The following input files were used for developing the 2009 GPA:

2009 Demand forecasts - Consultation December 2009

The 2009 generation scenarios were prepared using the 2008 demand forecasts. The Commission had noted that the 2009 demand forecasts would be peer reviewed before being published for consultation.

Two peer reviews indicated that the Commission's approach was reasonable and the Commission sought stakeholders' feedback on the 2009 demand forecasts. The deadline for feedback was 5pm on Friday 29 January 2010, three submissions were received.

Other technical reports

The report on Nuclear Feasibility below was completed by an undergraduate student and may be of interest to stakeholders. Nuclear options have not been used in the 2009 GPA's and the report is provided for information only.

Review of 2009 Demand Forecasts

The 2009 Demand Forecasts were updating using Statistics New Zealand’s latest population projections which resulted in a significant jump in forecast electricity demand. The Commission therefore asked Statistics Research Associates Ltd to review the existing models used for demand forecasting, including the development and testing of alternative modelling approaches to those currently used by the Commission.