Regional base forecast

Grid planning requires forecasts at a regional level in order to assess transmission requirements for servicing potential demand across geographical locations in New Zealand.

A paper outlining possible approaches to regional forecasting was prepared by J Lermit in October 2004.

The Commission has carried out a review of alternative regional forecasting methodologies based on currently available information. While a draft approach to regional forecasting was developed by the Commission, the different methodologies tested produced very different regional level forecasts. Therefore we believe it is essential to get a better understanding of the mix of demand types and historical growth patterns within each of the regional areas before settling on a final approach.

The current lack of publicly available information on the relative balance between the commercial/industrial load and the residential load in each region severely hampers the Commission’s capability in this respect. The Commission is therefore proposing to approach retailers to obtain data that would allow the split of commercial/industrial and residential load to be identified at a regional level.

The need for additional data is reinforced by the implications of the regional modelling carried out to date. For example, initial indications are that forecast demand in the northern half of the South Island may be understated at present.

• Paper outlining the regional forecasting review undertaken by the Commission

The draft regional forecast described here is a ‘work in progress’. It is not part of the Grid Planning Assumptions and has not been published in the SOO. In the SOO the Commission has adopted the Transpower regional demand allocation until it completes development of its own regional forecast.