The postalisation tariff consists of a capacity and commodity charge that applies for use of the Northern Ireland transmission network system.
The tariff calculation is based on the allowable revenue, as agreed with the Ofreg, and forecast demands. The tariff is set to give each pipeline owner their appropriate rate of return while also recovering their operating costs. Forecast capacities/demands set at the outset of the gas year are based on expected reserved capacity and expected commodity use of gas. There is a 75:25 capacity/commodity split to recover the allowable revenue on the system. The postalised tariff archive is available here.
The requirement to publish the Gas Transmission Charging Methodology Statement is specified in condition 2A.2.1.9 of each TSO’s licence. Under this Licence Condition, the TSOs are required to set out the approach to charging in respect of Overrun Charges and VRF Services. Annex A is included in this document for the purposes of satisfying the Licence requirement, and was approved by NIAUR on 30 June 2015.