Introduction to Exit Capacity
Exit capacity gives shippers an entitlement to take gas off the National Transmission System (NTS), and so capacity is often also referred to as ‘rights’ or ‘entitlements’. A shipper needs to buy 1 unit of capacity, in order to flow 1 unit of energy. Units for both capacity and energy are in kWh/day. If a shipper’s flow exceeds their capacity entitlements for any given gas day, then a shipper will incur overrun charges.
Firm & Off Peak Capacity
National Grid makes firm and Off Peak capacity available to the market at each offtake point. The volume of firm capacity made available at each offtake point consists of the following amounts:
Baseline Capacity (obligated) – As defined by National Grid Gas's Gas Transporter Licence
Incremental Capacity (obligated) – Firm capacity made available over and above baseline, in response to market demand and supported by User commitment. This increase in capacity is permanent.
Incremental Capacity (non-obligated) – at its discretion, National Grid can release additional firm capacity at an offtake point over and above obligated levels.
Off Peak capacity is made available to the market at offtake points where it can be demonstrated that firm capacity is not being utilised. The volume of Off Peak capacity available at an offtake consists of three parts:
Use it or Lose it (UIOLI) – any firm capacity that has been unutilised over recent days, can be resold to the market as interruptible capacity.
Unutilised MNEPOR - During D-1 at 13:30 the NTS Demand Forecast is published. Where this demand forecast is less than 80% of the annual peak 1 in 20 demand forecast, National Grid is obligated to release any remaining capacity up to the MNEPOR level as Off Peak capacity.
Discretionary - National Grid is able to make additional Off Peak capacity available to the market at its discretion.
If there are low pressures on the network, then National Grid may curtail Off Peak capacity rights, without any compensation for the Users affected.
Once a shipper has obtained a shipper licence then they can be considered a ‘User’ of the NTS under the terms of the Uniform Network Code (UNC). Shippers can obtain Exit Capacity by making applications or bids on the Gemini Exit system through a number of application windows and auctions. These applications or bids are allocated in accordance with UNC, and with consideration to National Grid’s incentive schemes. Details of the Exit Capacity application windows and auctions can be found within Section B of the UNC published on the Joint Office website.
National Grid NTS will monitor Users’ utilisation of their Available System Capacity at Interconnection Points (IP(s)).
After each 6 month period, consisting of 1 April to 30 September and the 1 October to 31 March, National Grid NTS will then, in accordance with the principles set out in the CMP LTUIOLI Guidance Document, identify whether or not a User(s) at an IP has underutilised its Available System Capacity and provide notification to that User of its utilisation.
LTUIOLI Guidance Document - Final
LTUIOLI Guidance Document - Marked up