Environment Agency
Emerging techniques are novel techniques for an industrial activity that, if commercially developed, could provide one of the following:
- a higher general level of protection of the environment
- at least the same level of protection of the environment and higher cost savings than existing best available techniques
This guidance is for production of hydrogen by electrolysis of water. This is an emerging technique.
You may need to prepare the hydrogen for:
- use on site
- export as a product
These activities are outside the scope of the guidance and you should discuss other permitting requirements with your regulator.
These environmental regulators (referred to as the regulators) worked with industry and other stakeholders to develop a review of emerging techniqueswhich informs this guidance:
- Environment Agency
- Natural Resources Wales
- Scottish Environment Protection Agency
- Northern Ireland Environment Agency (an executive agency of the Department of Agriculture, Environment and Rural Affairs)
Except where regulations apply, this guidance on emerging techniques is not a regulatory requirement but identifies best practice to address important environmental issues.
The regulators expect operators to follow this guidance, or to propose an alternative approach to provide the same or greater level of protection for the environment.
1.Who this guidance is for
This guidance is for:
- operators when designing and operating their plants and preparing their application for an environmental permit
- regulatory staff when determining environmental permit applications
- any other organisation or members of the public who want to understand how the environmental regulations and standards are being applied
This guidance covers all sizes of industrial plant (installations) producing hydrogen by electrolysis of water.
The guidance covers both new plants and variations (changes) to existing plants.
When you apply for an environmental permit for this activity, you must tell your regulator whether you are going to follow this guidance. If not, you must propose an alternative approach which will provide the same or greater level of protection for the environment.
In the UK, these installations are permitted under the:
- Environmental Permitting (England and Wales) Regulations 2016
- Pollution Prevention and Control (Scotland) Regulations 2012
- Pollution Prevention and Control (Industrial Emissions) Regulations (NI) 2013
For environmental permitting purposes, the hydrogen production plant is a:
- Part A (1) 4.2 (a)(i) inorganic chemicals activity in England and Wales
- Schedule 1, Part A 4.2 (a)(i) inorganic chemicals activity in Scotland and Northern Ireland
Some plant may be eligible for a simplified permitting process, a low impact installation or standard rules permit, where available. You can check with the environmental regulator for your plant location. For relevant guidance:
- in England, use the Environment Agencys guidance on A1 installations: environmental permits
- in Wales, use Natural Resources Wales guidance on installations
- in Scotland, use the Scottish Environment Protection Agencys guidance for part A installations
- in Northern Ireland, use the Department of Agriculture, Environment and Rural Affairs guidance on Integrated Pollution Prevention and Control (IPPC)
There are no existing best available techniques (BAT) reference documents (BREFs) or guidance which specifically cover the production of hydrogen from water by electrolysis.
WhereBATfor an activity is not covered in existingBREFsor where all the potential environmental effects are not addressed, the regulator must followArticle 14(6) of the Industrial Emissions Directive (IED).
This means that the regulator must set permit conditions including emission limit values (ELVs) for direct emissions to the environment, together with other permit conditions. These conditions must be based on the regulators own assessment of emerging techniques using the criteria listed inAnnex III of theIED. They should also consult with operators before setting these conditions. The regulators consulted industry and other stakeholders when developing the review of emerging techniqueson which this guidance is based.
Permits must protect the environment by setting conditions to make sure operators do not breach any environmental quality standards (Article 18 of theIED).
Your regulator may grant a?temporary derogation?of BAT-associated emission levels (BAT AELs) for up to 9 months, on the basis that hydrogen production by electrolysis of water is using an emerging technique (see?Article 15(5) of IED). (Derogation means having less strict emission limit values in the permit than the emission levels associated with the best available techniques.) You should discuss this with your regulator if this is likely to apply.
Your regulator will decide on the emission limits and other permit conditions that will apply on a case-by-case basis. They will do this based on the elements outlined in this guidance and the most appropriate source of reference. This is unless you can show that you can comply with an appropriate standard rules permit, where available.
Thereview of emerging techniquessummarises the available evidence used to inform this guidance. We refer to the relevant sections of the review in this guidance.
2.Technique selection
When designing a hydrogen production plant and its associated activities, you should consider its overall environmental performance.
You should justify your choice of technology at each stage using the principles of best available techniques throughout your permit application including:
- energy demand and efficiency
- water demand, efficiency and evaluation for re-use
- emissions to the environment
These are the hydrogen production by electrolysis methods the regulators considered when producing this guidance:
- alkaline electrolysis (ALK)
- polymer or proton electrolyte membrane (PEM)
- solid oxide electrolyser cell (SOEC)
The guidance may also be generally applicable to other types of electrolysers using water for hydrogen production. Consider it where appropriate.
The choice of technology will determine, for example, the energy required for compression. The selection will depend on the difference between the electrolyser system operating pressure and the pressure required by the user.
This guidance covers activities to prepare hydrogen ready for:
- use of hydrogen on site
- export of hydrogen as a product
These activities are outside the scope of the guidance and you should discuss other permitting requirements with your regulator.
Other associated activities may include:
- feed water treatment
- hydrogen purification and compression
- storage o