Legal framework: permissions and restrictions (and Ownership constraints (unbundling))

This LAP concerns the injection of hydrogen into the gas grid at the TSO level and the legal framework status covering authorised bodies and varying hydrogen concentration levels in the TSO transmission system along with potential changes to the regulatory framework to support enhanced hydrogen injection and utilisation


The existing national legal framework for the DSO to carry out hydrogen activities, which is normally restricted to natural gas. Ownership constraints refer to the constraints related to ownership associated with the process of injecting.
Is it a barrier?
Type of Barrier
Structural barriers, Operational barriers, Economic barriers, Regulatory gap
Assessment Severity


Question 1 Which is the responsible authority/legal entity for the permission of the connection/injection of hydrogen in the gas grid?
The DNO is responsible – in conjunction with the Health & Safety Executive (HSE) who would need to agree the connection (in terms of design and operation) on Health & Safety grounds The UK has a long standing privatisation framework covering the unbundling of the gas network to allow separate Distribution Network Operators (DNO), Transmission Network Operations (TNO) and System Operator (SO) roles, responsibilities and activities, to ensure fair access to the gas grid network for transmission and distribution purposes at transparent pricing – but permits only a low concentration of H2 in the gas stream at 0.1%. This was imposed at the time of transition to use of North Sea Gas and is in line with other European networks including AT, CZ, DK, ES, FI, GR, IE, IT, NO, PT, SE based on EN437:2003
Question 2 What is permitted or restricted according to national legislation under your responsibility as DSO regarding the transmission of pure hydrogen and mixtures of hydrogen and natural gas.
Gas injection is permitted – the DSO must comply with the Gas Safety Management Regulations 1996 (GSMR) which sets the permissible concentration of H2 to 0.1%
Question 3a - Is there a maximum concentration defined that you are allowed to transport as a DSO? (e.g. are you allowed to transport 100% hydrogen)
a - Maximum concentration of H2 is allowed to 0.1% applies to both DNO and TSO gas transport 0.1% H2
Question 3b - In case the maximum hydrogen concentration in your transmission grid (system) is less than 100%, is it allowed to inject pure hydrogen- 100%? into gas grid on transmission level (up to the allowed concentration)?
b - No – GSMR limits to be observed
Question 3c - If no, who is responsible for the blending with natural gas? Is there an obligation for the TSO to provide the necessary natural gas for blending the hydrogen (with several EU Directives transposed into national legislations the functions of gas grid operator and natural gas supplier are separated)
c - to comply with the permitted GSMR limit blending down to 0.1% would be required and in principle would need to be done in advance of injection
Question 4 If the concentration for injection is different than the maximum allowed concentration (question 2 and 3) question please answer this question What is the maximum allowed concentration in your country for injection in the gas grid on transmission level?
GSMR limit of 0.1%
Question 5 Are there specific requirements for increasing or decreasing the admissible threshold of hydrogen concentration (upstream and downstream networks, infrastructure elements and appliances with lower tolerance)? If yes: please describe.
There is an intent to allow higher H2 concentrations but this will mean changes to the primary legislation under the Gas Act and GSMR. The UK Health & Safety Executive HSE has looked at the case for a higher concentration of H2 in the gas network for sustainability and security of supply purposes and other reviews such as HyDeploy (testing gas with up to 20% H2 in a private network) and Hy4Heat, are considering H2 in gas flows as part of renewable Heat network use
Question 6 Are there specific restrictions/permissions for the transport of hydrogen other than “concentration” and “quality”, if yes which ones?
Question 7 If it can be guaranteed that the gas is on the required quality specification (on spec) at the next customer, is it allowed to feed in off-spec gas (read: a higher concentration of Hydrogen)?
Question 8 Which part of the connection facility (the injection installation is part of the connection facility) is owned by or under the responsibility of the DSO?
The connection facility is for the responsibility of the supplier looking to inject gas
Question 9 As TSO, do you see legal and administrative restrictions with regard to the ownership of your part of the connection facility (the injection installation is part of the connection facility) of hydrogen into the grid?
No – but H2 at high concentrations is currently a hypothetical option
Question 10 Is there a difference in legal and administrative restrictions between connections for hydrogen injection into TSO and DSO-networks? If so could you please specify the differences?
Question 11 Are there specific national (add-on) restrictions for the connection/injection of hydrogen in TSO networks compared to the connection/injection of natural gas? If yes: please name them. Are there other requirements for the injection of H2NG-blends compared to pure Hydrogen?
No. Must meet HSE safety and risk assessments
Question 12 Is it foreseen to review the current regulation to consider hydrogen injection into natural gas network and if yes on which term?
Potentially yes. A formal review is not expected in the short term, however current programmes supported by government (BEIS and HSE) such as the HyDeploy and Hy4Heat programmes are looking at options that might be implemented in the 2020’s (subject to change in laws) and the Leeds H21 study shows a longer term pathway to 100% H2 and the UKs HSE has already concluded that “injection of hydrogen at concentrations of 20% v/v or less is unlikely to have a deleterious effect on the gas network and most appliances". An amendment to the primary legislation would be required to support a higher concentration than currently written into law (Gas Act and Gas Safety Management Regulations )
Describe the comparable technology and its relevance with regard to hydrogen

National legislation:

  • Gas Act 1996
    Privatisation and unbundling of the gas industry; limiting the market power of British Gas; extending competition to industrial and domestic markets to obtain benefits of competition in terms of market entry and in benefits to customers
  • Gas Safety Management Regulations 1996
  • Pipeline Safety Regulations 1996
    Establishing a safe operations framework that applies to pipelines in Great Britain and to those in territorial waters and the UK Continental Shelf. Establishing a safe operations framework that applies to pipelines in Great Britain and to those in territorial waters and the UK Continental Shelf.
  • Utilities Act 2000
    Provided for the establishment and functions of the Gas and Electricity Markets Authority and the Gas and Electricity Consumer Council; to amend the legislation regulating the gas and electricity industries; and for connected purposes – subsequently to become the Office For Gas & Electricity Markets (OFGEM
  • UK Health & Safety Executive 1996
    The HSE has formal responsibility for enforcing health and safety law for gas supply management, transportation and storage 

EU Legislation:

  • Directive 2009/73/EC concerning common rules for the internal market in natural gas
    Directive 2009/73/EC establishes common rules for the transmission, distribution, supply and storage of natural gas.

    Its provisions and obligations apply to Hydrogen Gas by virtue of Article 1 (2), which states that the rules established by this Directive for natural gas, including LNG, shall also apply in a non–discriminatory way to biogas and gas from biomass or other types of gas in so far as such gases can technically and safely be injected into, and transported through, the natural gas system.

    Article 25 establishes the “Tasks of the distribution system operator” which include: ensuring the long-term ability of the system to meet reasonable demands for the distribution of gas […];shall provide any other distribution, transmission, LNG, and/or storage system operator with sufficient information […] as well as to ensure that the system operator does not discriminate between system users or classes of system including, including e.g. when setting rules for the charging of system users, etc

    Article 32 sets the rules on “Third party access”: access to the transmission and distribution system, and LNG facilities shall be based on published tariffs, applicable to all eligible customers, including supply undertakings, and applied objectively and without discrimination between system users.
  • Regulation 715/2009 on conditions for access to the natural gas transmission networks
    Regulation 715/2009 sets non-discriminatory rules for access conditions to (a) natural gas transmission systems; (b) LNG facilities and storage facilities taking into account the special characteristics of national and regional markets

    To achieve this, it sets harmonised principles for tariffs, or the methodologies underlying their calculation, for access to the network, but not to storage facilities, the establishment of third-party access services and harmonised principles for capacity-allocation and congestion-management, the determination of transparency requirements, balancing rules and imbalance charges, and the facilitation of capacity trading.
  • Regulation (EC) No 713/2009 of the European Parliament and of the Council of 13 July 2009 establishing an Agency for the Cooperation of Energy Regulators
    Article 1 Project matter and scope
    This regulation aims at:
    (a) setting non–discriminatory rules for access conditions to natural gas transmission systems taking into account the special characteristics of national and regional markets with a view to ensuring the proper functioning of the internal market in gas;

    Article 8 “Tasks as regards terms and conditions for access to and operational security of cross border infrastructure
  • Commission Regulation (EU) 2015/703 of 30 April 2015 establishing a network code on interoperability and data exchange rules
    The network code on interoperability aligns the complex technical procedures used by network operators within the EU, and possibly with network operators in the Energy Community and other countries neighbouring the EU.Article 7, Measurement principles for gas quantity and quality. In addition to interconnection points, Article 17 shall apply to other points on transmission network where the gas quality is measured. Article 18 shall apply to transmission systems. This Regulation may also apply at entry points from and exit points to third countries, subject to the decision of the national authorities.