Notes (for 2004 survey)
[ Last Updated 27 September 2007 ]
1. Calculations of effective charges are based on the assumption that the model domestic customer consumes 7000kWh/year of gas. Effective charges will vary by consumption level, due to differences in tariff structures (i.e. fixed charges versus variable charges). When evaluating the cheapest gas charges consumers are advised to assess tariff information provided from gas companies for their level of consumption.
2. Effective unit charges (c/kWh) are calculated using the following formula: (Total annual cost incurred by a 7,000kWh consumer)/7,000.
3. The total annual cost incurred by a 7,000kWh/year consumer is calculated as: (FC(incl GST)x365+VC(incl GST)x7000)(1-PPD), where FC represents the fixed daily charge, VC the variable charge and PPD the prompt payment discount.
4. In calculating the total annual cost it is assumed that the consumer pays on time and receives any prompt payment discount (PPD) offered. It is assumed that a consumer does not receive any direct debit discount.
5. Some companies have a number of plans in each region. The plan used in calculating the total annual cost is the one that has the lowest total cost i.e. the model consumer is assumed to be on the optimal tariff for their level of consumption (7,000kWh/year).
6. Tariff options that are not available to new consumers are not considered in the survey.
7. Distribution. Distribution charges do not include transmission charges or metering charges.
8. Retail. Retail charges across networks will vary due to, among other things, differences in transmission and distribution charges. Comparisons of charges across networks should be made with caution.
9. Some retailers offer an additional dual fuel discount to consumers who purchase both electricity and gas from them. To recognise this effective charges are also calculated with the dual fuel discount subtracted from the total annual cost incurred by the model consumer. These charges are presented under the Additional Discounts heading. These charges represent the effective additional charge that an electricity consumer of these retailers would face in receiving gas from these retailers.
10. Mercury Energy only supplies gas to their electricity consumers, hence only charges incorporating Mercury's dual fuel discount are reported.
11. Contact Energy only will supply new domestic connections to these networks.
12. All of Wanganui Gas' retail domestic consumers, as at the 1 October, qualify for a 5% loyalty discount on the variable component of their bill. This increases each year by 1% to a maximum of 9%. In the above table a 5% discount is assumed as standard. Effective charges with the full 9% discount are also calculated and presented under the Additional Discounts heading.
13. To 1 November 2003 gas measurement system charges were bundled with network charges. In the table the post 1 November 2003 meter charges have been subtracted from the pre 1 November 2003 line tariffs.
14. This figure represents the total of the above listed networks. Generally, only networks with 500 or more domestic consumers are covered in the survey. Therefore, not all networks with domestic consumers are surveyed.
15. Calculations based on most expensive and least expensive charges shown in the table, weighted by consumer numbers.
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