The pulse of the grid – energy transmission voltage explained
06 May 2025
When you flick on a light switch, charge your phone, or start heavy machinery at an industrial or even mine site, you’re tapping into a big and powerful system, that for the most part – many of us rarely think about. That system is high voltage transmission.
These systems are the hidden lifeline of our modern energy infrastructure, working tirelessly to carry electricity across regions, states and even sometimes, countries. So, what exactly makes high voltage so important, and when, should it be used?
Yurika’s General Manager Assets & Operations, Sam Bush explains,
“Voltage classification isn’t just a technicality – it determines everything from cable type to safety measures and infrastructure requirements.
Understanding these differences helps us ensure we design and build systems that are safe, efficient and future-ready”.
Understanding these differences helps us ensure we design and build systems that are safe, efficient and future-ready”.
To properly understand this spectrum of energy transmission, based on its role in the delivery of electricity, here are the definitions we work to in Australia:
Low voltage (LV) —
up to 1,000 volts
(used for residential and small commercial connections)
High voltage (HV) —
11 kV, 33 kV and 66 kV
(used for regional and bulk supply to zone substations)
Extra high voltage (EHV) —
132 kV, 275 kV, 330 kV volts and 500 kV
(used for major transmission lines across long distances)
Working with high voltage infrastructure, understandably brings with it serious risks, including electrical arcing, equipment failure, or exposure to hazardous energy, and as a result, Australian standards require strict compliance and rigorous procedures to protect both people and assets.
“From design to maintenance, every part of a high voltage system must meet exact safety standards,”
So why high voltage and what are the benefits you ask?
First and foremost, is the reduction in energy losses. A key advantage of transmitting electricity at high voltage is that it lowers the current required for a given amount of power. This greatly reduces energy loss along the lines (often known as ‘joule heating’).
“Efficiency over distance is a real driver here” explains Yurika’s Manager Field Services Lines, Travis Jacklin.
“Lower current means less wasted energy, and that’s so important when you’re moving electricity hundreds of kilometres across Queensland, the east coast, or any space across our vast country.”
The second benefit is notably lower infrastructure costs.
Really, how? You ask.
High voltage enables the use of thinner, lighter cables which not only reduces material costs, but also makes transmission towers lighter and cheaper to install. It’s an ideal combination of both performance and practicality.
The final benefit is long-distance reliability.
“It’s impossible to support Australia’s energy transition without robust, high voltage infrastructure” said Travis.
“It’s what connects regional or remote generation to city demand and underpins the entire National Electricity Market”.
And so, Australia’s geography demands long-distance energy transmission HV and EHV systems to make it possible to move power seamlessly from generation to consumer.
While overhead towers and lines are probably the most recognisable of elements of these HV systems, they also involve many other components working together to safely deliver reliable energy.
Overhead lines, are arguably the most recognised backbone component of long-distance transmission, designed for strength, reliability and minimal power loss. They feature conductors, insulators, support towers, corona rings, and earthing systems.
Whether in remote or urban areas, substations also play a critical role. They step the voltage levels up or down, and manage safe transition from generation to transmission to distribution.
“A critical component of our HV systems, is also SCADA (Supervisory Control and Data Acquisition)” said Sam. “This technology helps us monitor, control and protect networks in real time, and nowadays, many of these systems are highly automated. This level of visibility and control is critical to maintaining uptime, especially during peak demand periods or in extreme weather events” he said.
At Yurika, we’ve been delivering high voltage networks, generator grid connections and major infrastructure projects cross Australia for some time now.
From early planning to energisation, we offer complete turnkey solutions, built to national standards and shaped by our deep industry experience.
Whether you’re developing a renewable project, integrating distributed energy resources, upgrading an industrial facility or mine site, or simply extending your grid capacity, our specialist teams can help you explore whether a high voltage solution may be just what you’re looking for.
