Demand forecasting

The Commission develops forecasts of future electricity demand at national, regional, and grid exit point level. These forecasts are the starting point for decision-making about new investment in transmission, generation, and demand-side response. The demand forecast is published in a Statement of Opportunities (SOO), and is required to be used by Transpower in forming its Grid Upgrade Plans.

The Commission’s approach to forecasting has been to develop base forecasts that project forward on a ‘business as usual’ basis, using historical indicators of demand for electricity. Step changes in demand are then modelled separately, and used to adjust the base forecast (for example new energy efficiency programs, technologies, or industries). This approach enables the impact (or benefits) of the ‘step-changes’ to be quantified and incorporated into scenarios.

An initial set of national and regional demand forecasts was prepared by the Commission in 2004 and published as part of the 2005 SOO.

In 2006 the forecasting methodology was reviewed. Revised forecasts were published as part of the May 2007 draft Grid Planning Assumptions.

A further revision of the May 2007 demand forecasts was prepared as part of the preparation for the draft 2008 SOO. The resulting energy and peak demand forecasts, and associated review document have been published as part of the 2008 draft grid planning assumptions.

Taking into account comments received in submission, the Commission has prepared the following updated demand forecasts:

• National and regional energy forecasts xls [43 KB]
  
• Excel summary of forecast input data xls [58 KB]
• Regional peak demand forecast document pdf [234 KB]
  
• Annual peak forecasts in text file format zip [26 KB]
  
• Mean ADMD forecasts xls [1329 KB]
  
• Prudent ADMD forecasts xls [1329 KB]
• Regional load probability forecast document pdf [323 KB]
• Regional load probability forecasts in text file format zip [260400 KB]
  
• Regional load probability plots zip [766 KB]
• MATLAB national and regional energy models zip [56 KB]
• MATLAB ADMD models and scripts zip [136456 KB]
  

The Commission published the draft 2008 SOO for consultation on 4 July 2008.

The Commission held an industry workshop in Wellington on Monday 21 July 2008 to set out the key results of the work, describe the content and processes used and provide a forum for discussion to assist participants in their submission process.

Following consultation, the Commission will finalise the demand forecasts.

The above forecasts are all long-term econometric projections covering at least 30 years. For shorter time frames, the Modelling Group have recently completed a Security of Supply medium-term demand forecast extending to 2012, which has been used in the 2007 Reserve Energy Needs Assessment (RENA). An update of this forecast is currently in preparation.

Contact Brian Kirtlan for any further information on the Commission's demand forecasting work programme.