The two most common options for utility power lines are overhead and underground power lines. Both have their advantages and disadvantages. We will discuss these power lines and what the future holds for us.
How Are Overhead Power Lines Beneficial?
The overhead power lines can transfer a higher current capacity voltage of up to 400 kV than underground power lines that can transmit 66 kV. Underground power lines are mostly used to transfer smaller capacities of 33 kV.
Overhead power lines are comparatively easy to install than underground cabling. Furthermore, adding extra connections to the overhead power lines is easier. The contractors must consider soil conditions and conflicting power lines when installing underground power lines. Moreover, performing upgrades and replacements in underground power lines is also complex. Accidents with underground power lines are rare, so they are mostly repaired after they have completed their life span.
Overhead power lines are cheaper because they are insulated only at the contact tower. Conversely, underground power lines are insulated all over. Thus, the cost is the deciding factor which explains why overhead power lines are widely used. Underground cables have superior insulation that needs to withstand soil, chemicals and weather, so they are over ten times pricier to manufacture. Moreover, as underground power lines are more expensive, they are harder to replace and upgrade.
How Are Underground Power Lines Beneficial?
The Quality of the Signal
As underground power lines are placed underground, they deliver high-quality signals without any interference. Conversely, overhead power lines are vulnerable to signal interferences and are more likely to suffer from voltage drops. Moreover, overhead power lines interfere with the signals of communication lines.
Underground lines are safer as people can’t get into contact with underground power lines. Underground power lines are not affected by natural disasters as much as they impact overhead ones. The risks of death and injuries to people are much higher with overhead power lines.
Underground power lines provide a clean and seamless look to the cityscape as you’ll not see wires hanging through the air space.
Underground power cables are better for the environment as they don’t generate as much sound as overhead power lines. Furthermore, underground power lines are not involved in as many accidents with forests and wildlife, including vulnerable species.
Overhead Vs Underground Power Lines In Australia
Less than 7% of households in Australia are served by underground power. While more prominent outer suburbs have this facility, you’ll see overhead wiring in older suburbs. However, some of these older suburbs are located near the city centres and demand higher property values.
Which Countries Of The World Have Only Underground Power Lines?
Well, only a tiny minority of countries where most power lines are placed underground are in Europe. All low and medium-voltage power lines are placed underground in the Netherlands. Whereas in Germany, around three-third of medium-voltage power lines and nearly ninety percent of low-voltage power lines are underground. Due to the safety of underground power lines, there is a lower risk of power outages and electricity-related injuries in these countries. Due to the limited current transmitting capacity of underground power lines, mostly overhead power lines are used everywhere in the world for transmitting high-voltage power.
What Does The Future Hold for Overhead & Underground Power Lines?
Overhead power lines will be there as they can carry higher voltages, are easy to repair and have low costs. However, serious efforts are being made to develop underground power lines further as they offer better safety and uphold environmental concerns. Aussies will use both underground and overhead power lines in combination in the future because utility companies like to use the benefits of each.
Apart from overhead and underground power lines, a third alternative is available, known as aerial cables. They are positioned above the ground like overhead power lines but are entirely insulated, making them safer and helping avert electrical shock. Furthermore, they are safeguarded to avert electromagnetic interference. Aerial cables are standard in Japan and are pricier than overhead power lines.