Aug 2016
Gas Transmission
Gas Quality 2020
Aug 2016
Sep 2017
National Grid Gas Transmission
John Harris (Project Manager) , Robyn Jenkins (Stakeholder lead contact) ,
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Network Innovation Allowance
Gas Transmission Networks
It is predicted that the future shift of gas supply sources will drive the requirement to reconsider the basis of the current GS(M)R specifications so that the UK gas market is able to operate efficiently and continue to attract these alternative sources of supply. In addition there are a number of other factors that make a review of the GS(M)R prudent at this time being:-

European gas quality harmonisation.

The European Commission has asked ENTSOG (European Network of Transmission System Operators for Gas) to develop a draft amendment, following a detailed impact assessment, to the EU Network Code on interoperability to codify the CEN standard EN 16726 (Gas Infrastructure – Quality of Natural Gas – Group H.) by the end of June 2017. At present the standard does not include a Wobbe Index component but there are detailed differences in other areas from the current GS(M)R specification.

The European Commission is continuing the process over the next few years of finding a consensus on the Wobbe Index range for the next version of the CEN standard. One key option for this is the adoption of the EASEE “H-gas” Wobbe range

UK Wobbe Range

Currently the UK Wobbe range is narrower than in most other EU gas markets. Maintaining this narrower range could affect the attractiveness of the UK market to upstream parties if such parties would incur additional gas processing costs for entry into the UK compared to other markets.

The project seeks to deliver an assessment of the likely impacts of legislative or supply changes on gas quality and the downstream impacts on the National Transmission System.  This will include a concise review and explanation of where an impact is anticipated, a detailed study when an impact is not known and an assessment of the impacts with required mitigating options, including time and cost. The report will also provide the range of gases that the NTS can accommodate with no material or economic impact. This information will provide the foundation of NGGT’s ongoing gas quality management ensuring an effective and efficient management of the network for all stakeholders.  

The output of the programme will provide an assessment of equipment, processes and specifications that would be impacted if a change to gas quality specification is required to meet a maximum / minimum limit from across the selected specifications of GS(M)R, CEN and EASEE ‘H’ Gas. The assessment must provide sufficient information that NGGT will be able to communicate to an external audience a clear understanding of the type of NTS assets impacted by a widening of the Wobbe within UK and an estimate of the further work required and options available to mitigate the risks identified. This further work, if required, will be accompanied by associated estimates of the costs and timescale to achieve this work as necessary.

This evaluation could then be used as a common process baseline for the NTS assets from which any future changes in gas quality can be related.