Risks with extra low voltage solar photovoltaic (PV) systems

Queensland’s Electrical Safety Office investigated the electrocution of a person who was modifying the solar panels on an off-grid solar PV system in a remote area. The deceased was found with significant burns to their hands and fingers.

The investigation found the solar PV system operating at around 100VDC, had been operating at an extra low voltage (not exceeding 50VAC or 120V ripple-free DC). The person performing the work was not required to be a licensed electrical worker, however, this incident highlights the real risk of working on such installations.

Anyone working on solar PV systems requires specific skills and knowledge to understand electrical safety and installation requirements, particularly when it comes to DC voltages.

A licensed electrician must be engaged to carry out work involving installation and maintenance of solar PV systems that are operating at and above low voltage (greater than 120 volts DC and greater than 50 volts AC).

Safe work practices and compliance to safety standards for equipment and installations is imperative, and can reduce risks associated with such systems, such as electric arcing, electric shock, and fire risks.

Issues to consider:

• Even at extra low voltage there can be significant electrical current in solar PV systems that can cause arcs and burns to the body (even solar panels operating at extra low voltage create electricity while the sun shines on the panels). Panel-to-panel connections and disconnections are a significant risk.
• Health issues could compromise situations, even at extra low voltages, because cuts, wounds, or ulcers can reduce resistance or medical issues involving pacemakers can be aggravated.
• Environmental conditions (such as high humidity or wet seasons and heavy rain) can increase risks, especially if the extra low voltage is at the higher range.
• Remote locations may have difficult access which could hamper assistance, so extra precautions are warranted.
• If located on a roof or other structure, there are working from heights and fall risks, as well as when accessing the roof (ensuring secured ladders).
• Failure to weatherproof the electrical parts creates a fire risk.
• Safety standards to ensure safe means of isolation should be followed.

The exact effect from extra low voltages depends on the size of the voltage, which parts of the body are involved, how damp the person is, and the length of time the current flows.

Regardless of voltages present, safety standards for equipment and installations should be followed to reduce risks associated with any solar PV systems. It’s also important, especially in a remote area where there may be high humidity, that risk assessments and mitigating actions are taken to reduce chance of shock, burns, or fires, while working on or using extra low voltage solar PV systems.

More information

Read the Managing electrical risks in the workplace code of practice 2021 (PDF, 1.34 MB) .