Learnings

Outcomes

This FMEA is an initial screening of the items or failure modes associated with functional risk of the transition to Hydrogen operation. The aim was to provide a comprehensive overview of the risks associated with transmission of hydrogen, but as yet many of the risks are only loosely defined.

Although the failure modes may be similar for the equipment regardless of process fluid, the associated risk of failure may well change with Hydrogen. This work has identified a few known risks, but it has not gone into that level of detail systematically as there are many unknowns in terms of hydrogen consequence analysis for compressor stations and it was out of scope for this project. The changed risks identified are also predominately operational challenges, but new safety and environmental risks may become more evident once more detailed design work is undertaken. 

Further analysis is required as the operational concept, asset configuration and network design are evolved, and more information becomes available. This should include development of this FMEA and further work such as the following for each compression station once a specific process design and layout is available and updated as the designs progress from feasibility, concept through to detailed design: 

-          Hazard Identification (HAZID) 

-          Hazard and Operability Analysis (HAZOP)

-          Review of DSEAR and ATEX rating and zoning 

The major risks identified at this stage can be summarised as: 

1.       Fire and Gas detection systems. This applies to both blended hydrogen and 100% hydrogen operation. Failure of these systems have the potential for progression to the most serious events, and as yet are largely unproven in operation for hydrogen transmission today. They will naturally be a focus to ensure safe operation of the network compression stations. 

2.       For 100% Hydrogen operation, the risks associated with use of hydrogen as a fuel in the existing gas turbine fleet that are reliant on development and qualification of new technology to ensure reliable and safe operation.

There are many more medium risk failure modes identified that have the potential to develop to high risk once more information becomes available, and therefore this analysis should be updated as and when possible.

Value tracking

                                           Data Point                                        Data Point Definition

Maturity                             TRL2-3                                               This project has increased NGT's knowledge of potential component compatibility with hydrogen at compressor stations, however more work is required to deepen the understanding.

Opportunity                       100% of single asset class                The project findings are applicable to all NGT compressor stations.

Deployment costs              -                                                        This project has not resulted in any solutions which can be deployed.

Innovation cost                  £91,784                                             This cost includes site visits and desktop work to produce the FMEA studies, as well as workshops to discuss and challenge the findings.

Financial Saving                 -                                                        There are currently no financial savings associated with the delivery of this project, however the repurposing of compressor stations for hydrogen operation could result in significant savings in the future.

Safety                                 -                                                        This project has not delivered any direct safety improvements, however it has increased NGT's understanding of component compatibility with hydrogen at compressor stations.

Environment                      -                                                        This project has not delivered any direct emissions savings, however transitioning the NTS to hydrogen could result in significant environmental benefits in the future.

Compliance                        Supports compliance                       This project supports the development of the hydrogen safety case which will demonstrate compliance with GSMR and other regulations in the future.

Skills & Competencies       Individuals                                        Individuals directly involved with the project have gained an understanding of the key areas which may be affected by the introduction of hydrogen at compressor stations.

Future proof                      Supports business strategy              The project findings will help enable hydrogen in the NTS and support the energy transition.

Lessons Learnt

•                     The original project plan included 3 weeks to attend the selected sites and gather the required data, however due to site availability, it took significantly longer to attend all sites. In future projects, more time should be allocated to attending sites and virtual meetings should be considered where appropriate to save time. 

•                     There were several key stakeholders to the project including NGT’s rotating equipment Subject Matter Experts and the Process Safety team. The challenge for the FMEA studies was conforming with the same approach to safety as the Process Safety team. Ultimately, this project did not go into the same level of detail as would be expected by the Process Safety team due to time constraints. It was agreed that this work was just an initial investigation into compressor station compatibility with hydrogen and that significant follow on work is required to apply the safety elements to the project, including ignition consequences, safe distances and occupied building proximity.