Energy use data is collected for the Waikato Region as a whole and for the Hamilton area.
The amount of energy used in the Region is monitored by Environment Waikato every 3-4 years. Energy use relative to GDP is also monitored at 3-4 year intervals
The first energy survey for the Waikato Region was conducted in 2003.
We obtain GDP data from Statistics New Zealand.
Fuel consumption and energy use data is obtained from industry, electricity line companies, fuel suppliers, surveys and from local authorities. Fuel consumption data are converted to energy use based on the calorific value of the fuel. Energy consumption data includes losses from within the electricity line network and losses associated with the conversion of fuel to energy.
We obtain electricity data from electricity line companies, who estimated industrial versus domestic consumption.
We estimated data for domestic coal, wood and gas use from a survey of home heating methods and fuels. This was carried out for Hamilton, Te Kuiti, and Tokoroa in 2001 and for Taupo, Huntly, Matamata and Putaruru in 2000. We used home heating data from the 2001 census in conjunction with these data to estimate fuel use for other areas of the Region. Data for 2003 were estimated using Statistics New Zealand population projections.
We estimated LPG use for transport using national LPG use statistics. Data for the Waikato Region were based on Transit New Zealand territorial local authority VKT data.
We obtained data for industrial gas use from resource consent data and from contacting industries directly. We targeted industrial activities holding consents for discharges to air, although a few other processes were also included. Methods for estimating gas use for domestic heating are outlined above.
We estimated transportation fuel use using petrol tax data provided by territorial local authorities. We estimated aviation fuel use based on the proportion of national aviation fuel consumed in the Waikato Region. This was based on aviation carbon dioxide emissions data from the National Transport Emission Inventory. We estimated energy use associated with diesel consumption from rail transport using data from the 1998 Ministry of Transport (MOT) Report Impacts of Rail Transport on Local Air Quality, data from the New Zealand Transport emission inventory and fuel use information supplied by Tranzrail.
Energy use data are reported for the Region based on the 2003 calendar year. These data were compared with GDP data for the year ending March 2003 and presented by sector.
Table 1 shows energy consumption per total GDP by sector for the Waikato Region for 2003. These comprise baseline energy consumption data to GDP data. Future indicators for energy will show trends over time in energy use relative to GDP.
Table 1: Energy consumption by sector
|% energy consumption / GDP by sector||21%||6%||73%||100%|
Data are also presented for the energy use of different activities relative to their contribution to the Regional GDP. The graph below shows the relative contribution of the different standard industry classification (ANZSIC(external link)) categories to national GDP and the Waikato Region’s GDP.
The graph below shows the energy use by ANZSIC sector per dollar contributed. Domestic heating and passenger transport both contribute to energy use but are not part of the classification system. In this graph, energy use from these sectors is included in the property and business services sector and the transport and storage sectors respectively. Forestry related activities such as wood and paper product manufacturing, including sawmilling and timber dressing, are included under manufacturing. Similarly, activities relating to dairy product manufacturing are included under the manufacturing classification, rather than agriculture.
This indicator depends on industry, electricity line companies, fuel suppliers, fuel transporters and local authorities providing energy use data. Data were not provided by some sources, due to commercial sensitivities, and other less accurate methods of estimating fuel use were used. For example, aviation fuel consumption data and Rockgas gas use data were unable to be provided for commercial reasons. The methods used to estimate fuel use from these sources are likely to be less accurate than total fuel consumption data from retailers.
Petrol tax data were provided for Hamilton, South Waikato, Hauraki, Matamata-Piako, Thames-Coromandel, Waikato and Waipa Districts. These areas contain about 75 percent of the total number of dwellings in the Waikato Region. Petrol tax data from these areas were used to estimate fuel use for the rest of the Region.
No fuel tax data were available for Hamilton alone. Hamilton data were based on estimates of fuel use for Hamilton from road network modelling, carried out by Gabites Porter for the 2001 air emissions inventory. This was extrapolated to 2003 based on projected population growth. These methods provide less accurate estimates than if petrol tax data had been obtained specifically for the whole study area and if the Hamilton use data were able to be segregated on the basis of fuel use.
Trends in energy use per GDP will be incorporated into the indicator once the Regional Energy Survey has been repeated.
No technical quality assurance documents have been prepared outlining process, data quality assurance or validation techniques.