Hydrogen: planning and consenting guidance

2. About Hydrogen

2.1. What is Hydrogen and How is it Used?

Hydrogen is a highly versatile, simple and abundant element. Like fossil fuels it can be combusted to create heat in industrial and residential settings, it can be used to power transport (including in fuel cells) or as a feedstock in chemical processes and production of sustainable fuels, and it can be stored and used to generate electricity (hydrogen-to-power). Unlike fossil fuels, it does not produce CO₂ emissions when combusted. It therefore has the potential to play a significant role in the de-carbonisation of a wide range of sectors and activities particularly including heavy duty and long-distance transport, high-temperature heat for industry, chemical manufacture processes, sustainable fuel production as hydrogen-to-power and as a long-term store of energy. This versatility and range of use cases means green and blue hydrogen can make a significant contribution to achieving net zero carbon emissions. There is however potential for combustion of hydrogen to produce oxides of nitrogen (NOx) a local air quality pollutant and consideration should be given to emissions to ensure air quality standards are not breached.

The use of hydrogen as a fuel source or feedstock is not new. Hydrogen has been produced and utilised at a major scale in Scotland’s chemical and industrial sectors for many years and its application and characteristics are well understood. However, the production of hydrogen today is almost entirely as ‘grey’ hydrogen, which is reliant on extracting hydrogen from fossil fuels through the reforming of natural gas.

2.2. Green & Blue Hydrogen

Low-carbon (‘blue’) and renewable (‘green’) are fast emerging as new modes of producing hydrogen, involving carbon capture and renewable energy technologies to produce clean hydrogen that can be utilised as a low or zero-carbon fuel source, feedstock, or energy store.

• Green (or renewable) Hydrogen – is produced from the electrolysis of water using renewable electricity. The electrolysis process uses an electrical current to split water into its constituent parts of hydrogen and oxygen (H₂O). When linked to the electricity generated from on-shore and off-shore renewables, the production of green hydrogen through electrolysis is zero carbon.
• Blue (or low-carbon) Hydrogen – is produced in the same way as grey hydrogen through reformation of natural gas or biogas to extract hydrogen. However, it integrates carbon capture, utilisation and storage (CCUS) systems to capture carbon dioxide emissions and transport them for safe geological storage. Blue hydrogen is therefore very low-carbon and is considered a viable option for the decarbonisation of energy intensive industries.

These new, modes of hydrogen production are based upon well-established technologies and production processes. Green hydrogen in particular is a modular technology capable of operation at a diverse range of sites, but in many cases similar in scale and nature to other industrial processes and energy infrastructures. It can typically be housed within standard warehouse buildings, or often in ‘modular’ containers within a secure site. Associated plant and equipment such as water treatment, cooling systems, compression and pressurisation are often situated externally or in separate buildings within a single site.

For green hydrogen in particular, the overall environmental impacts of production are typically relatively low. Through established measures of planning control and environmental mitigation, production should be capable of being safely and sustainably accommodated in a range of settings across Scotland. Nonetheless, it remains important that any emissions (e.g. noise, odour), discharges (e.g. waste-water), and other activity associated with hydrogen production (e.g. vehicle movements), are clearly detailed and assessed as part of proposals. Measures to avoid, minimise, and mitigate impacts should be pro-actively identified at an early stage in design development and reviewed with the planning authority and other consultees.

Green and blue hydrogen projects will emerge in a range of configurations and scales as the hydrogen sector continues to mature, and as technologies evolve. In the short-medium term many hydrogen projects may be relatively small-scale as operators look to establish pilot, demonstrator, and ‘scale-up’ facilities with potential to grow over time. These may be co-located with existing renewable energy projects such as constrained onshore wind, and look to utilise related land and infrastructure.

As demand for hydrogen grows both domestically and internationally, larger and more complex projects and associated infrastructures (such as pipelines or utility-scale storage) are likely to come forward, with potentially more complex consenting requirements.

Further detail on core site requirements, characteristics, and infrastructures involved in green and blue hydrogen production are set out in Annex A.