What is the Gas Quality Working Group?
A group of experts brought together to facilitate the production of a new IGEM standard specifying the quality of gas that is allowed to be injected into the UK’s gas transmission and distribution network.
Working Group Documents
All of the documents produced by this working group are available here.
Changes in gas quality have the potential to impact the whole of the supply chain and the makeup of the gas quality working group aims to reflect this. The individuals involved represent: the Health and Safety Executive (HSE), National Grid Transmission, the Gas Distribution Networks (GDNs) Cadent, SGN, Northern Gas Networks and Wales & West Utilities, Energy UK, the Industrial and Commercial Energy Association (ICOM) and boiler manufactures. In addition the working group has input from a number of specialist consultants including DNV GL and Kiwa.
Why is this standard required?
The UK benefits from a long established gas network with a proven history of delivering natural gas safely, affordably and reliably to millions of customers each year. However, if we are to meet the target of an 80 per cent reduction in greenhouse gas emissions by 2050, then it is essential that we consider how we will continue to supply heat, power and light whilst reducing our impact on the environment.
In response to the emissions challenge the gas industry has embarked on a number of innovative projects designed to decarbonise the gas network and reduce the carbon footprint associated with gas usage. Many of these projects explore the potential of alternative, low carbon gases such as biomethane, bioSNG and hydrogen.
Some low carbon gases are already being added into the network alongside natural gas. However, in order to maximise the full potential of alternative gases a change is required to the specification of gas that is permitted to be injected into the network.
The current specification for UK gas quality sits within the Gas Safety (Management) Regulations 1996 and was developed based upon the characteristics of North Sea natural gas. As an increasing percentage of the natural gas used in the UK is imported and we seek to increase the use of low carbon alternatives to natural gas, there is a requirement to change the specification of gas that is permitted for use under the GS(M)R and to align the UK standard with the European standard.
How is gas quality measured?
Gas quality is measured by the Wobbe index which is used to compare the combustion energy output of different composition fuel gases in an appliance (fire, cooker etc.). If two fuels have identical Wobbe indices then for given pressure and valve settings the energy output will be identical.
The Wobbe index is a critical factor in minimising the impact of substituting natural gas with low carbon alternatives. Each of the various types of low carbon gas measures differently against the Wobbe index and some do not fit within the parameters set out within GS(M)R. For example, the Wobbe index requires the addition of propane to some upgraded biomethane products.
The IGEM gas quality standard will set a new Wobbe index range for gases used within the UK network. Initially it will extend the upper range however it will seek to widen the lower range at a later date.
The publication of an IGEM standard covering gas quality. This work is a pre-curser to a request to change the specification of gas quality that sits within GS(M)R in order to enable an increase in the use of low carbon gases alongside natural gas.