Safe use of hydrogen-fuelled generators

Introduction

Hydrogen-fuelled generators are an alternative to diesel-powered generators. They can be used as back-up power or where mains power is not available. Hydrogen-fuelled generators create less emissions, noise and particulate generation than diesel-powered generators. Hydrogen-fuelled generators produce electricity through either:

• an electro-chemical reaction between hydrogen and oxygen gas (electrolyser), or
• the combustion of hydrogen gas (hydrogen combustion engine).

For the purposes of this guidance, a hydrogen-fuelled generator system includes:

• hydrogen storage vessels such as manpacks and tube trailers, and
• hydrogen gas pressure reduction equipment, and
• a generator, which includes associated control and power equipment.

The system can operate either as standalone plant or be integrated with other power infrastructure on site. Hydrogen is often delivered to site in high pressure cylinder packs or tube trailers. These are connected to the generator system.

Using a hydrogen-fuelled generator system at a workplace introduces new hazards and risks. These risks need to be understood, assessed and controlled before the system is installed and used. This guidance provides information about the outdoor installation of stationary hydrogen-fuelled generators only.

Hydrogen hazards

Hydrogen is a colourless, odourless and tasteless gas. This means it is hard to detect a hydrogen leak. Hydrogen also burns with a clear flame. This makes detecting fires more difficult and presents a hazard to anyone in the area, as well as for emergency response.

Hydrogen is classified as a dangerous good. It is a ‘Class 2.1 Flammable Gas’ with an ignition energy 13 times lower than LP Gas. It is also lighter than air. This means it can dissipate easily and rise to the highest point of an enclosed or low airflow area, where it can accumulate.

Hydrogen will ignite very easily when exposed to an ignition source, including static discharges. Hydrogen may also heat up when it is depressurised and may cause ignition if vented or if a leak occurs.

Hazard profile of hydrogen

Assess and control the risks

Not all sites are suitable for hydrogen-fuelled generator systems. A risk assessment should be conducted before installation to help to determine:

• if the site is suitable for a hydrogen-fuelled generator system
• the best location on site for the generator system
• what risk controls need to be in place before a hydrogen-fuelled generator system is installed.

The risk assessment should be undertaken by a suitably competent person. It should consider:

• The location of the work site and any physical or environmental factors that could increase the risk of using a hydrogen-fuelled generator system.
• If appropriate separation distances can be maintained around generator systems.
• How hydrogen will be delivered and stored on site.
• How generator systems will be protected from impact and secured against unauthorised access.
• How hazardous areas will be identified and maintained.
• How potential ignition sources will be controlled. For example, static electricity, lithium batteries, tools that generate sparks (hot works).
• What fire protection needs to be in place.
• What emergency response planning will be required.
• How hydrogen-fuelled generator systems will be maintained. For example, making sure vents are clear of blockages.

Site location and layout

Before installing a hydrogen-fuelled generator, make sure the site is appropriate. Think about:

• What existing infrastructure and plant is currently on site?
• What infrastructure and plant might be on site in the future?
• Are there any management overlays on the site? For example, bushfire management or land subject to an inundation (flooding).
• Are there flammable or combustible materials, other dangerous goods, vegetation or overhanging trees on site?
• Does vegetation on site need regular maintenance? For example, mowing of grass around generators.
• Do you need to seek advice from Fire Rescue Victoria on site location and layout?
• Can the venting from the generator be directed away from buildings, air intakes and ignition sources?
• Is the site in an area known to have lightning strikes? Could a generator act as a lightning rod?
• Is the site close to:
  • houses
  • schools
  • aged care facilities
  • hospitals
  • correctional facilities
  • other populated areas or uses that could make evacuation difficult?
• Is access to the site restricted? Is there more than one way to access the site in case of an emergency?
• Is there a suitable firefighting water supply available near the generator site? For example, an on-site hydrant, fire water supply or street hydrant?

Separation distances

An appropriate separation distance should be maintained around hydrogen-fuelled generators. The appropriate separation distance will depend on a range of factors. These include the volume of hydrogen being stored on site and the site layout. The risk assessment should consider what the appropriate separation distances are for each generator.

The risk assessment should consider what other hazards are nearby, for example:

• work involving potential ignition sources, such as electrical or mechanical equipment
• vehicle, plant or pedestrian traffic
• other dangerous goods or incompatible materials
• areas where people are likely to congregate, such as emergency evacuation points
• areas with potential ignition sources, such as designated smoking or vaping areas, barbeques etc.

WorkSafe recommends the following minimum separation distances for hydrogen-fuelled generators. A risk assessment should be undertaken to determine the appropriate separation distances for each generator and each site.

Recommended minimum separation distances

Delivery, storage and handling of hydrogen

Before any generators or hydrogen packages are delivered, the site should be appropriately prepared. Hydrogen is typically delivered to site in tube trailers or smaller manpacks of high-pressure cylinders.

There is a risk of impact when plant, such as forklifts, are used around hydrogen packages. This could lead to serious injury from leaks, fires or explosions. This should be considered when:

• delivering, storing or moving hydrogen packages
• using plant in the area around hydrogen-fuelled generators and hydrogen packages
• planning works in the vicinity of hydrogen-fuelled generators.

Connections between hydrogen packages and fuel cells need to be completed by a suitably qualified gas fitter. This work should be planned in advance so there is sufficient time to install and commission the generator before use. More information on installing and commissioning fuel cells and fuel cell systems is available on the Energy Safe Victoria website.

Both full and empty hydrogen packages need to be stored and handled safely. Empty hydrogen packages need to be treated as though they are full unless confirmed to be gas free. Even when pressure is reduced, residual gas may be present, creating a risk of leak or explosion.

Hydrogen-fuelled generators and hydrogen packages must be secured, for example using perimeter fencing and locking valve panels. Install visible signage to clearly identify flammable gas hazards and access restrictions. Anyone without training in hydrogen safety should not enter areas where hydrogen-fuelled generators or hydrogen packages are stored.

Impact protection

Hydrogen-fuelled generators and the area around them must also be protected from impact from vehicles or mobile plant, so far as is reasonably practicable. Impact protection should be in place before hydrogen gas is delivered to the site. Impact protection can include concrete jersey barriers or water-filled barriers.

Traffic management

Appropriate traffic management can reduce the risk of impact from vehicles or mobile plant on hydrogen-fuelled generators. Site traffic management plans should consider the location of hydrogen-fuelled generators and how to limit or exclude plant movement near them. This includes movement of reversing or slewing machinery. The separation of people from hydrogen-fuelled generators should also be considered, for example using:

• physical barriers such as fences
• speed limits
• one-way traffic-flow systems
• dedicated pedestrian and vehicle paths.

Storing certain quantities of dangerous goods

Specific legal duties apply if a workplace stores or handles dangerous goods above the amounts specified in the table in Schedule 2 of the Dangerous Goods (Storage and Handling) Regulations 2022. WorkSafe has guidance on complying with requirements for storage and handling of quantities of dangerous goods in excess of the Schedule 2 amounts.

Hazardous areas

A hazardous area is an area where there is an explosive atmosphere present or likely to be present. Hazardous areas are classified into zones by AS/NZS 60079.10.1:2022 Explosive atmospheres, Part 10.1: Classification of areas — Explosive gas atmospheres. The immediate vicinity of a hydrogen-fuelled generator system is likely to be classified as a zone 2 hazardous area, unless verified otherwise.

The person in control of the installation of a hydrogen-fuelled generator is responsible for classification of a hazardous area. This classification should be carried out by a suitably competent person. Hazardous area classification should be conducted in line with the AS/NZS 60079 series of standards.

Any plant or electrical equipment used in a hazardous area needs to be certified for use within that zone. This includes powered mobile plant such as forklifts, power tools and lighting.

Any employees working in hazardous areas need to be trained in:

• the risks posed by flammable atmospheres
• how to work safely in a hazardous area
• static control
• emergency response.

Control of ignition

Static electricity

Hydrogen is sensitive to static. An accumulation of static electricity can lead to a spark which can cause ignition. >p?Static electricity can be generated by a range of sources including:

• movement of people, materials and plant
• clothing or PPE that is not static dissipative
• plastic surfaces, such as plastic matting, shade cloth or plastic chairs
• dry and dusty conditions
• mobile phones and radios.

Risk controls to manage the risk of ignition from static electricity, in and outside of hazardous areas, include:

• Ensure hydrogen-fuelled generator systems are adequately grounded. This should be verified by scheduled resistance testing and maintenance, where appropriate.
• Ensure any plant or equipment that is used for hydrogen systems have appropriate static controls. For example, use of specialised anti-static PTFE tapes on connection points.
• Provide employees with anti-static personal protective equipment (PPE), clothing and footwear.
• Use Ex rated tools and equipment.
• Establish safe handling procedures for hoses and fittings.
• Develop a static control plan.

Use of lithium batteries

Lithium batteries can be found in, or attached to, hydrogen-fuelled generators. If a lithium battery short circuits, it can overheat and ignite.

To control the risk of short circuits and ignition:

• Separate Battery Energy Storage Systems (BESS) from flammable and combustible goods.
• Protect lithium batteries from impact or water ingress.
• Ensure only trained employees access charging or maintenance points.
• Where hydrogen-fuelled generators contain battery units, ensure that any vents for the battery compartments are directed away from the hydrogen gas supply.
• Ensure vents for hydrogen-fuelled generators are not placed or directed near a BESS.

Fire protection

Hydrogen will combust quickly if ignition occurs. Appropriate fire protection must be provided for any site where flammable or combustible liquids or gases are stored.

There should be sufficient methods to cool and maintain hydrogen packages within safe limits to avoid ignition. There should be procedures in place to shut off the supply of hydrogen in case of fire.

Fire protection could include deluge, fire spray systems, portable extinguishers, hose reels etc. The fire protection system must be:

• properly installed, tested and maintained, and
• always accessible to people on site and emergency services, and
• able to be used with equipment that emergency services use, without any adaptation or modification.

Depending on the volume of hydrogen stored at the site, you may also need to seek advice from Fire Rescue Victoria on fire protection. Specific legal duties in respect of fire protection apply if a workplace stores or handles dangerous goods above the amounts specified in the table in Schedule 2 of the Dangerous Goods (Storage and Handling) Regulations 2022.

WorkSafe has guidance on complying with these legal duties.

Emergency response planning

Emergency procedures need to be in place before a hydrogen-fuelled generator system is installed on site. When developing emergency procedures, review information provided by the:

• supplier or installer of the system, and
• occupier of the premises, and
• relevant emergency services.

The details of any engineering controls built into hydrogen-fuelled generator systems should be included in emergency procedures. For example, remote emergency stop, automatic shut-off or leak detection.

Emergency procedures should include information about:

• the location and volume of hydrogen gas on site
• how to isolate the system
• the location of other hazards on site, such as dangerous goods stores
• evacuation measures.

Site evacuation plans, egress routes and emergency information books should be updated to include information about the location of hydrogen-fuelled generators.

Guide 115 of the NTC Australian and New Zealand Emergency Response Guidebook provides evacuation measures for flammable gases, including hydrogen.

Understand your legal duties

Suppliers of plant

Suppliers of plant have duties under the Occupational Health and Safety Act 2004 (OHS Act) and the Occupational Health and Safety Regulations 2017 (OHS Regulations). These duties apply to new, used and hire plant.

A person who supplies plant to a workplace must:

• ensure, so far as is reasonably practicable, that the plant is safe and without risks to health, if the plant is used for the purpose it was designed, manufactured or supplied for, and
• give information to each person they are supplying plant to. This information must include:
  • the purpose for which the plant was designed, manufactured, or supplied, and
  • any conditions necessary to ensure the plant is safe and without risks to health, if the plant is used for the purpose it was designed, manufactured or supplied for.

More information about plant supplier duties is available in the Plant compliance code.

Employers

Employers have duties under the OHS Act. They must, so far as is reasonably practicable:

• provide and maintain a working environment that is safe and without risks to the health of employees and independent contractors, and
• provide employees with the necessary information, instruction, training or supervision to enable them to do their work in a way that is safe and without risks to health, and
• ensure that persons other than employees are not exposed to risks to their health or safety arising from the conduct of the employer’s undertaking, and
• consult with employees when identifying or assessing hazards or risks and making decisions about risk control measures. Consultation must include any health and safety representatives.

The OHS Regulations require employers to ensure that employees and persons supervising the employees are trained and given information and instruction about hazards related to plant, including:

• the processes for identifying hazards and controlling risks, and
• safety procedures associated with using the plant at the workplace, and
• the use, fit, testing and storage of PPE, if relevant.

Occupiers of premises where dangerous goods are stored or handled

The Dangerous Goods (Storage and Handling) Regulations 2022 set out legal duties for occupiers of premises where dangerous goods are stored or handled.

Occupiers of premises where dangerous goods are stored and handled have a range of duties, including duties relating to:

• consultation, and
• information and training, and
• hazard identification and risk control, and
• security.

Relevant Standards

• AS/NZS 60079 Explosive atmospheres series
• AS 4332-2004 The storage and handling of gases in cylinders
• SA TS 5359:2022 The storage and handling of hydrogen
• SA TR 15916:2021 Basic considerations for the safety of hydrogen systems
• AS/NZS 1020:2023 The control of static electricity in non-hazardous areas