This project will gather safety evidence to support the delivery of a Village Trial of hydrogen gas supply. Future roll-out of hydrogen will be influenced by the suitability of existing natural gas installations to be safely repurposed for hydrogen use. The purpose of this project is to consider, identify, and mitigate all risks associated with repurposing an existing gas installation to hydrogen.
Benefits
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Learnings
Outcomes
The outcomes of the project are reported on in a single report, ‘EUSE Hydrogen Domestic Pipework Conversion – Final Report’, by Kiwa Energy. This is the report that is currently being reviewed by HSE. A summary of the key outcomes is as follows:
- Air permeability data for 24 domestic properties of various layouts which will inform ongoing research into ventilation of homes, and the use of gas detectors, with respect to the safe use of hydrogen. This is being further investigated in an ongoing NIA project, ‘Dispersion of Helium Releases in Domestic Properties’.
- Recommended conversion procedure for domestic gas installation pipework – informed by experimental data and practical demonstrations carried out by this project. The procedure includes the following key steps:
Several walks of the system to understand the likely route, sizing, and quality of the gas pipework installation.
More than one Gas Safe Registered engineer having passed judgement on the whole installation to assess its suitability before repurposing to hydrogen.
A series of 20 mbarg tightness tests, in accordance with IGEM/UP/1/B Edition 3, in natural gas, air, and hydrogen will be undertaken to confirm gas tightness.
A single, one-off, elevated pressure test at 1 barg (to be formally approved/accepted by wider industry) with the meter and appliances disconnected, to provide further, non-intrusive, assurance of installation pipework integrity and enable the detection and replacement of any poorly installed pipework joints.
- Recommendations on skills and competency required for operatives who will be carrying out the early hydrogen conversions.
- Review of novel inspection technologies and details of next steps required to develop bespoke solutions for the inspection of domestic gas installation pipework.
It is the belief of the project team that the outcomes will enable sufficient confidence from UK Government and the gas industry, that existing domestic gas installation pipework can be safely repurposed to carry hydrogen.
Lessons Learnt
The key lesson learnt has been the importance of being flexible with the project plans in first-of-a-kind research such as this. The methodology, while remaining largely the same, did change to enable some detailed experimental testing to be undertaken which has resulted in the project recommending a novel approach to domestic gas installation pipework assurance that could not have been foreseen at the start of the project. As part of this the project team also learned the power of demonstration of new ways of working to enable stakeholder confidence. The demonstrations undertaken at British Gas’ Academy enabled all project partners to have confidence in the recommendations being put forward and this simply would not have been the case based on the lab testing alone.
The research and subsequent demonstration undertaken by the project is thought to have been very effective in relation to the problem it was tasked with solving. A critical part of this result was the approach taken to stakeholder engagement. As alluded to throughout this report, the project received a lot of scrutiny from across industry. In response to this, the project partners organised a technical workshop in March 2023 which helped shape the experimental testing undertaken. Key stakeholders who had concerns at various points throughout the project were HSE, DESNZ, and IGEM, and they were all part of this workshop and any further engagement on the back of it. Further demonstration to these stakeholders will be required to enable standards to properly reflect the research however, and a project is being developed to deliver this.
The final key lesson learnt was the importance of having industry leading experts involved in the core project team. Whilst Cadent and Kiwa were the lead partners on the project, having representation from DNV to enable outputs to feed into their developing QRA model, as well as British Gas (not involved at the project outset but a conscious effort from Cadent to bring in) as downstream gas installation experts really helped in enhancing the power of the project outputs.
The learnings from the project can be exploited further in early hydrogen heating demonstrations (e.g., H100 Fife) where the project outputs can be further refined as necessary, based on a real-world feedback loop. The topic of elevated pressure testing in domestic gas installations was one that generated great concern at first, however, it is believed that the research conducted by this project and the recommendations put forward will allay these concerns. In early hydrogen heating demonstrations at least, it is likely that this project will form the basis of any installation pipework conversion in domestic properties.
The value of these lessons will be validated by the HSE review which is due to complete in early 2024.
