Greenhouse gas (GHG) emissions

It is necessary for us to release quantities of methane (which is a potent greenhouse gas) from the commissioning, operation, maintenance and decommissioning of the assets in the system. We are incentivised on the quantity of greenhouse gas emitted from our system compressors as these are currently the most significant venting source.

Each asset type on the NTS has different characteristics including the extent to which gas is inherently released, or periodically vented, as part of its operation or maintenance.

Greenhouse gas emissions incentive

The current Greenhouse Gas Emissions Incentive compares actual venting quantities against a defined volumetric allowance of 2,897 tonnes per year.
The new scheme running from April 2021 for 5 years, replaces the downside only scheme to a mirrored upside/downside scheme with a Cap and collar of £1.5m+/-, which means that there is now scope for National Gas to earn revenue from venting if below the allowance but will be penalised for any venting in excess of the allowance. The scheme value is based upon the Treasury's Green Book providing government analysts with rules for valuing energy usage and greenhouse gas emissions. You can view our performance on this incentive by downloading our Supporting Information document.

 

Operational performance

We are also investigating alternatives to venting natural gas, which will identify the potential to reduce emissions from assets such as compressors and chromatographs taking into account the operational and mandatory maintenance requirements.

Supporting documents

National Grid Gas Transmission Venting Verification Statement 2019

Verification of Venting Reporting for Gas Transmission 2019