Work package 7
Safety assessment
This work package focused on assessing the safe use of hydrogen gas in certain types of domestic properties and buildings.
The Health and Safety Executive (HSE) has independently reviewed the Hy4Heat Safety Assessment and has written a letter of assistance to BEIS confirming its relevance to gas network operator future duty holders for trials.
What does this mean?
This assessment indicates that the use of 100% hydrogen can be made as safe as natural gas is when used for heating and cooking in certain types of houses (detached, semi-detached and terraced houses of standard construction), that were studied.
This is an important milestone on the pathway to the first community trials using hydrogen as a heating source, which should generate important learning to support policy decisions on the role of hydrogen in decarbonising heat.
The HSE has independently reviewed the evidence provided and has formally stated its view that the conclusions provide an appropriate basis for designing a trial and informing the risk assessment for a trial. The HSE view assures gas network operators can draw on these results to plan initial trials, such as the neighbourhood trial as set out in the Ten Point Plan.
In the Ten Point Plan, the Government committed to support industry to begin a large village hydrogen heating trial, and to set out plans for a possible pilot hydrogen town before the end of the decade. BEIS is working with industry to deliver the wider safety, cost and feasibility evidence that will be needed before any future decisions are taken on further trials or network conversion.
What are the limitations?
This analysis does not mean that any type of trial or wider rollout of hydrogen have been proven to be safe, feasible, or economically viable. The scope of the assessment was limited, and substantial further work will need to be done. In addition, any gas network operator proposing trials will need to demonstrate all necessary safety arrangements have been made for the specific trial site.
The scope of this first safety assessment was limited in a number of ways, including:
The findings are not applicable to flats, multi-occupancy buildings, and other housing that lacks natural ventilation or was out of scope of assessment
The assessment only considered the safe use of hydrogen downstream of the emergency control valve (ECV), not the safety of supply through gas networks to the home. This is currently being investigated separately through projects being managed by Gas Distribution Network Operators (GDNOs)
6 July 2021, HSE documents and Annex to support Site Specific Safety Cases
HSE Letter of Assistance – 27.5.21
HSE letter of assistance to BEIS / Operators of future 100% hydrogen heating trials
Hy4Heat: HSE Conclusions Memo – May 2021
HSE conclusions memo of the review of the Hy4Heat Safety Assessment
Annex to Site Specific Safety Case for Hydrogen Community Demonstration
Annex prepared to support Site Specific Safety Cases for hydrogen gas community demonstrations, based on work undertaken by the Hy4Heat programme. It covers a collection of recommended risk reduction measures for application downstream of the Emergency Control Valve (ECV)
6 JULY 2021, SAfety Assessment: Precis summary and Conclusions documents
Safety Assessment: Precis
An overview of the Safety Assessment work undertaken as part of the Hy4Heat programme
Safety Assessment: Conclusions Report (incorporating Quantitative Risk Assessment)
A comparative risk assessment of natural gas versus hydrogen gas, including a quantitative risk assessment; and identification of control measures to reduce risk and manage hydrogen gas safety for a community demonstration
6 JULY 2021, Safety AssessmenT: assessments and analysis Documents
Safety Assessment: Consequence Modelling Assessment
A comparative modelling assessment of the consequences in the event of a gas leak and ignition event for natural gas and hydrogen gas
Safety Assessment: Gas Ignition and Explosion Data Analysis
A review of experimental data focusing on natural gas and hydrogen gas ignition behaviour and a comparison of observed methane and hydrogen deflagrations
Safety Assessment: Gas Dispersion Modelling Assessment
A modelling assessment of how natural gas and hydrogen gas disperses and accumulates within an enclosure (e.g. in the event of a gas leak in a building).
Safety Assessment: Gas Dispersion Data Analysis
A review of experimental data focusing on how natural gas and hydrogen gas disperses and accumulates within an enclosure (e.g. in the event of a gas leak in a building)
Safety Assessment: Gas Escape Frequency and Magnitude Assessment
An assessment of the different causes of existing natural gas leaks and the frequency of such events; and a review of the relevance of this to a hydrogen gas network
6 July 2021, Safety Assessment: experimental testing documents
Safety Assessment: Experimental Testing - Domestic Pipework Leakage
Comparison of leak rates for hydrogen and methane gas from various domestic gas joints and fittings seen in typical domestic gas installations
Safety Assessment: Experimental Testing – Commercial Pipework Leakage
Comparison of hydrogen and methane leak rates on a commercial gas pipework system, specifically the gas meter and equipment contained within the Plant Room of an MOD site
Safety Assessment: Experimental Testing - Cupboard Level Leakage and Accumulation
Comparison of the movement and accumulation of leaked hydrogen vs. methane gas within cupboard spaces in a typical domestic property
Safety Assessment: Experimental Testing - Property Level Leakage and Accumulation
Comparison of the movement and accumulation of leaked hydrogen vs. methane gas within a typical domestic property
Safety Assessment: Experimental Testing - Ignition Potential
Investigation of the ignition potential of hydrogen-air mixtures by household electrical items and a comparison with the ignition potential of methane-air mixtures
9 JUNE 2021, WP7 DOMESTIC HYDROGEN PURGE PROCEDURES
The aim of the report, written by Steer Energy, was to review the current purge standards for UK domestic installations, in particular IGEM/UP/1B, and to carry out experiments to assess the validity of those standards for use with hydrogen. These activities were carried out in order to understand and recommend safe purge practices for hydrogen in a domestic environment.
5 June 2019, BEIS appoints WP7 contractors
BEIS has appointed DNV GL and Steer Energy to conduct a range of comparative experimental tests, using both natural gas and hydrogen, that simulate scenarios found in domestic environments to quantify the relative risk of using hydrogen versus natural gas - as part of demonstrating and de-risking the use of hydrogen for heating in UK homes and businesses.
Steer Energy will undertake WP7 Lot 1:
Lot 1: Research and evidence gathering to compare the fitness for purpose of fittings and general pipework within a typical domestic property for both hydrogen and natural gas
DNV GL will undertake WP7 Lots 2, 3, 4:
Lot 2: Research and evidence gathering to compare the movement and accumulation within different confined spaces within a typical domestic property for both hydrogen and natural gas
Lot 3: Research and evidence gathering to compare the movement and accumulation of leaked gas within a typical domestic two storey property for both hydrogen and natural gas
Lot 4: Research and evidence gathering to compare the ignition risk from different gas concentrations for both hydrogen and natural gas
6 MArch 2019, WP7 ITT PUBLISHED
The ITT has been published for contractors to carry out safety assessments for the suitability of hydrogen in existing buildings. Suppliers now have until 12 April 2019 to submit applications.