The risk of transmission lines starting a fire is extremely low, and they are designed and managed to minimise these risks.

In recent decades across Australia, there have been only two instances where transmission lines have caused a fire (validated with transmission companies in New South Wales, Queensland, Tasmania and Victoria).

It's important to note that there have been fires started or exacerbated by some types of distribution lines, in particular Single Wire Earth Return and 22kV lines. The 2009 Victorian Bushfires Royal Commission found that these smaller powerlines running near trees were the key fire risk that needed to be managed.

For clarity, distribution lines carry lower voltages of electricity to homes and businesses; there are probably some outside your house or farm. Transmission lines carry high voltages of electricity over long distances; they are tall structures and have large clearances or are sometimes placed underground. Once electricity is generated, it moves along the transmission line, then through a transformer, then to the distribution lines to get the power where it's needed.

Transmission networks are unlikely to start or be damaged by fire because:

• Transmission lines are supported on tall towers (up to 80m high)
• The lines have dedicated corridors (easements) with an average width of 50 metres, which allow access to private land to maintain infrastructure
• There is greater control of vegetation growing immediately underneath the lines, which reduces the risk of contact from trees and branches
• If transmission component failures do occur, they often occur in extreme weather events that are usually accompanied by rain (e.g. cyclones and thunderstorms)
• Individual transmission line conductors are separated by great distances and are not likely to clash during extreme weather events.

When bushfires do burn near to transmission lines, there are increased risks – but energy and emergency management agencies work hard to restrict fire near to these assets and minimise the risk to ongoing power supply.

Former Fire and Rescue NSW Commissioner and veteran firefighter Greg Mullins says taking extra precautions around higher-risk infrastructure during fires is part and parcel of the job – and transmission lines are "nothing new."