Electric power transmission: powering our everyday lives

Have you ever asked yourself how electricity gets to your house from a power plant? 

Although we don't think about it much, it’s crucial to our daily existence. The system that delivers electricity from power plants to residences, businesses and industries is known as electric power transmission. Without these systems, our power wouldn't reach its destination.

Power delivery in Australia is changing due to the country's shift to renewable energy. Beca is pleased to contribute to the process of updating infrastructure to facilitate this shift. We're assisting in connecting renewable energy sources in rural locations to the cities and towns that need them. Our efforts include overcoming huge distances and completing difficult modifications to maintain the system's stability and efficiency.

What is electric power transmission?

Electrical power transmission is the large-scale movement of electricity from generation plants to distribution networks, maintaining reliable delivery to consumers. It’s a complex system with multiple components working together to transport power efficiently.

Power plants, the source of the electricity that runs our daily lives, are often thought to be at the centre of it all — even though they're physically located at the fringes. That’s where transmission comes into play. This allows the energy created by these plants to power our daily lives.

How it works:

1. Power plants produce electrical energy.
2. Electricity is transported in power lines or cables at a high voltage level. High voltage is used to reduce energy loss over long distances.
3. Substations step down the high voltage to a medium voltage level more suitable for safe local distribution, as well as being cost-effective and space-efficient.
4. A distribution network delivers this electricity to consumers.

Electricity transmission primarily uses alternating current (AC) because it can be easily stepped up or down using transformers, allowing for high-voltage transmission, which minimises energy loss over long distances. Also, AC infrastructure is generally less expensive than its direct current (DC) counterparts. Hence, AC power grids have been developed extensively, forming a ubiquitous, versatile infrastructure compatible with a wide range of residential, commercial and industrial loads. 

However, at high voltage, DC plays an important role in specialised applications, such as underwater cables, and, due to its lower losses, connecting very distant renewable energy sources to the power grid. Together, AC and DC systems make sure electricity reaches consumers efficiently and effectively.

Overhead vs. underground power lines

Source: Europacable 

What are the differences between the two main types of power lines, and what are some of the advantages and disadvantages of the two?

• Overhead transmission lines carry high voltages between 110 kV and 500 kV and are used for long-distance transmission. The conductors are made of materials like copper and aluminium, and held aloft by towers. Overhead lines are usually used in rural or remote areas where crossing long distances is a critical factor, and the appearance of these structures is not of major concern. These types of lines are also cheaper to install and maintain, but are unsightly and can be damaged by adverse weather conditions, which may affect their reliability.

• Underground lines — although more costly to install and maintain — have the following advantages in some cases. These can be more suitable in urban and environmentally sensitive regions, as they are less detrimental to the aesthetic value of the area and less susceptible to adverse weather conditions. However, owing to high costs and installation complexities, their use is generally restricted to short spans or in areas where appearance and reliability are particularly important.

In Australia, other issues such as fire risk and animal life also influence which one of these options is employed. At Beca, we always consider these factors to offer solutions that will meet the needs of the project in terms of cost, reliability and environmental impact. To learn more, visit our Transmission and Distribution services.

What is the role of substations in power distribution?

Beca project: Hawera Substation Refurbishment 

Substations are the key nodes of moving electrical power from the generators to the loads. They are where voltage levels are altered and power is switched or diverted during fluctuations or changes in demand, making sure the grid's balance and reliability. Substations might not look glamorous; however, they are packed with vital components continuously operating in the background that make it all happen safely:

• Transformers change voltages so that the electricity is at the right levels for transmission, distribution and use.
• Circuit breakers act as very fast switches and are the system’s protectors, stepping in to isolate any power infrastructure experiencing faults and hence reduce damage.
• Surge arrestors shield sensitive equipment from damaging voltage spikes.
• Busbars are the energy highways, distributing electricity efficiently within the substation.
• Remote monitoring systems are the watchful eyes, making sure everything runs smoothly and any issues are spotted quickly.

These components work together to maintain the grid’s stability, minimise supply losses and damage should there be any failures, and provide a steady electrical supply. For instance, at Chalmers Street and Granville Junction Substations in Sydney, we employed 3D modelling and virtual reality to enhance system design. Our goals were to increase the substation’s capacity within a constrained physical footprint and to make it easier to maintain. These upgrades addressed constraints at the site near Central Station and incorporated the distant Granville Junction, enabling the substations to handle the increased power demands from the new air-conditioned trains. 

By enhancing the reliability of service for millions of rail users, projects of this nature have shown how innovation can enrich power supply delivery. 

Strategies for efficient power transmission

When discussing power transmission, we must also address the issue of efficiency during the delivery of electricity to accommodate Australia's growing energy needs and transition to renewable sources. How we resolve these problems isn't just a matter of technological innovation. We also need innovative social and economic policies that complement new tech and help sustain the community in the long run.

Advanced smart grids have the potential to transform our approach to energy management. Real-time digital systems and automation will continuously improve supply dependability. Smart grids achieve this by monitoring consumption, load balancing and optimised energy management. As the grid becomes more reliable and the available infrastructure is used more effectively, there will be fewer outages, and the overall system will become more efficient.

High Voltage Direct Current (HVDC) cables support the transmission of power across great distances throughout the country. These systems have less power loss and are more controllable than conventional AC networks when transmitting power long distances from renewable sources to settlements, and this offsets their initial higher cost. By enhancing our ability to regulate how power flows, this technology contributes to the stability and supply of the grid. 

However, technology alone does not solve all challenges. We also need well-thought-out policies to clear the way ahead. To achieve this:

• The Powering Australia Plan is creating jobs in the clean energy sector and aims to lower energy prices as well as decrease emissions¹. 
• The National Energy Transformation Partnership is an alliance between various departments dedicated to transforming Australia’s energy network, while also targeting carbon neutrality by 2050². 
• The Future Fuels and Vehicles Strategy, on the other hand, helps Australia move away from more polluting forms of transportation and toward the long-term safety of alternative fuels³.

Challenges in power transmission

Beca project: Deakin University Microgrid

Maintaining and modernising transmission infrastructure throughout Australia's diverse regions comes with significant challenges.

Physical and logistical hurdles
Australia’s varied geography makes installing power transmission systems difficult. Long transmission lines connect remote renewable energy sources like solar and wind power to urban areas. For example, some transmission projects have 200 kilometres of high-voltage lines, demonstrating the challenge of transporting electrical energy over long distances while limiting environmental impact. Navigating rough terrain and reducing influence on local ecosystems are key problems, as are dealing with fire dangers and wildlife protection.

Social licence and community engagement
Community acceptability is critical for many transmission projects. Farmers, for example, have raised concerns about the visual and environmental impact of transmission lines⁴. Issues like this underline the importance of effective community engagement and fair compensation. In keeping with this, landowners in New South Wales earn $200,000 per kilometre of new transmission infrastructure over 20 years. However, sometimes remuneration alone is insufficient to obtain permission. Furthermore, without community involvement, projects may face delays and increased costs.

Cost of underground versus overhead cabling
The choice of underground or overhead cabling has a considerable impact on project costs and community acceptance. Underground cables, while less visually invasive and more weather-resistant, are significantly more expensive to install and maintain. Overhead power transmission lines are less costly and easier to repair, but they are typically considered eyesores and are more prone to natural calamities such as bushfires. The decision must strike a balance between expense, environmental impact and societal acceptance.

Reliability and energy security
Maintaining grid dependability and energy security is critical. We need an extensive transmission network to connect renewable energy to our existing grid — but this integration also creates security risks, such as transmission failure and infrastructure stress. HVDC and smart grids can improve efficiency and reliability, but the infrastructure must withstand Australia's harsh weather and long distances. For example, the Nyngan Solar Farm project (more on this later) highlights how Beca addressed connectivity and environmental concerns while prioritising efficiency and maintainability.

Integrating renewable energy into the transmission grid

The challenge with renewable energy initiatives is that they are typically located in isolated locations far from the cities that require electricity, i.e., the supply/source is not where the demand is. Building the right transmission infrastructure is essential to reducing energy losses and preserving grid dependability. Unfortunately, Australia's vast and wild landscape doesn't make things easy. With that being said, every project needs a different technological answer, whether you're operating in a rugged mountain range or a large desert.

In addition to practical considerations, we also need to keep the environment in mind. In isolated or environmentally delicate areas, local ecosystems are especially susceptible to the disturbance that transmission line construction may bring about. Thorough environmental assessments are not just nice-to-haves; they are necessary to protect endangered species and maintain natural ecosystems. However, the human aspect is just as important. We must interact with local communities and address their concerns over the project's appearance and the use of the land to win their trust and support.

By solving these challenges, we can connect renewable energy to Australia’s electrical grid and make real progress toward a sustainable future. Learn more about our wider Energy capability. 


Source: New Atlas 

The Nyngan Solar Farm is a fantastic example of what is achievable. Set in outback NSW, the Nyngan is Australia's largest solar farm, with over 1.3 million PV modules scattered across 250 hectares. It powers around 33,000 dwellings. At Beca, we addressed the project's connectivity and environmental difficulties by establishing and assessing plans to meet Australian standards. It demonstrates how renewable energy can be reliable, efficient and cost-effective all at the same time.

However, there are still misconceptions regarding renewable energy. Some are concerned about the visual impact of solar farms and mistrust their effectiveness at replacing the current non-renewable energy sources. However, effective planning and open communication with communities can alleviate these worries. Furthermore, new technologies make renewables more reliable than ever. Nyngan, for instance, highlights how solar power can deliver — and why it’s a wise investment for Australia's future energy needs. 

Read more about our solar farm projects here.

Powering a sustainable future with Beca

Connecting renewable energy to Australia’s transmission grid isn’t straightforward. Wind and solar farms are often far from the cities that need their power. Bridging these distances means navigating tough terrain and addressing environmental concerns while working closely with communities.

At Beca, we take a practical, people-first approach to these challenges. Our team combines advanced technology with thoughtful planning to reduce environmental impact and work toward gaining community support. We don’t just design and build infrastructure — we also engage with the people affected by them, listening to their concerns about how the lines will look and how the land will be used. This helps us earn trust and approval while delivering projects that work for everyone.

With decades of experience, we know what it takes to make the electrical grid more resilient and integrate renewable energy efficiently. Our focus on sustainable solutions not only strengthens Australia’s energy system, but also supports the nation’s goals for energy security and sustainability.

With every project we take on, we aren’t solely interested in meeting technical demands — we also aim to benefit the communities we serve and make every day better. Learn more about how we’re shaping the future of Australian power transmission or contact us today to discuss your project needs. 



 

Sources

1. Australian Government | Department of Climate Change, Energy, the Environment and Water - Powering Australia
2. Australian Government | Department of Climate Change, Energy, the Environment and Water - National Energy Transformation Partnership
3. Australian Government | Department of Climate Change, Energy, the Environment and Water - Future Fuels and Vehicles Strategies 
4. Farmers for Climate Action - Enhancing community engagement in transmission building rule