Safe placement of Battery Energy Storage Systems on construction sites

Background

Battery Energy Storage Systems (BESS) contain Lithium-ion batteries. They are used to power electrical equipment where site power may not be available.

A BESS may also be used to:

• power plant such as tower cranes and piling rigs
• provide general site power and lighting.

Some construction sites use large BESS units. These larger units may provide as much power as a community BESS and contain a similar quantity of Lithium-ion batteries. For example, a tower crane BESS may be rated for 500kW. A community BESS can range from 20kW to 5MW.

These large BESS units are designed with explosion or deflagration panels. These panels are usually built into the roof of the BESS unit. They ensure that if the batteries inside the BESS unit overheat or catch fire, any explosion, deflagration, fumes and smoke are directed upwards. This helps protect any people who are at ground level near the BESS unit.

Safety issues

When overheated, Lithium-ion batteries of all sizes can catch fire. The fire is often hard to put out and the smoke can be toxic.

If a BESS unit is designed with explosion or deflagration panels in the roof, the fumes and smoke are directed upwards. This can affect or prevent people safely evacuating elevated plant and equipment like tower cranes. This risk is increased if there is only one means of evacuation.

Recommended ways to control risks

Do not place BESS units where:

• employees are working near the top of, or above the BESS
• the only way to evacuate is alongside the BESS unit. For example, next to the base of a tower crane.

When positioning BESS units on site:

• Ensure there are clear evacuation routes so people can safely evacuate away if the BESS unit overheats or catches fires. Plan the evacuation route so people are not exposed to any fumes or smoke from the BESS, particularly near the top of the unit or near other vents. If the site does not have sufficient room for evacuation routes, do not use a Lithium-ion BESS unit.
• Place units at least 3m away from equipment and plant access ladders. For example, access ladders for tower cranes and other elevated work areas. If a 3m clearance is not possible, place fire rated barriers between the BESS and areas where people work.
• Consider site conditions such as surrounding buildings and prevailing wind conditions. Position BESS units to limit potential impacts from any fumes or smoke.
• Consider site access for emergency services responders. Where possible, provide alternate access paths should one path be blocked by fumes or smoke.
• Ensure there is an easily accessible way to disconnect or isolate power and the BESS unit.
• Have emergency response plans that address the risk of a Lithium-ion battery fire. Emergency response plans should include clear instructions for people to:
  • evacuate the area via a suitable route, or shelter in place whilst awaiting rescue if it is not safe to evacuate
  • not try to extinguish a fire involving Lithium-ion batteries.

Legal Duties

Employers have duties under the Occupational Health and Safety Act 2004. 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
• 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
• ensure that persons other than employees are not exposed to risks to their health or safety arising from the employer's conduct
• 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 Occupational Health and Safety Regulations 2017 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 risk
• safety procedures associated with using the plant at the workplace
• the use, fit, testing and storage of PPE, if relevant.