Why Japan Uses Overhead Power Lines Instead of Underground?

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Why Do Tokyo’s Streets Have Overhead Power Lines Instead of Underground Cables?

The travelers may noticed that the streets of Tokyo, and much of Japan, filled with unsightly overhead power lines. All across Japan, there are about 40 million utility poles, which is equal to the number of cherry trees in the country. If you walk down almost any street or side road, you’ll see a network of overhead wires held up by poles made of concrete, steel, or wood.

It has fueled criticism that the city’s development lags far behind places like Paris, London, Fort Collins, Hong Kong and some developed cities in China, where 100% of power lines are buried underground, while in central Tokyo, only 10% are.

More than travelers and visitors, the general public often wonders why Japan has so many crowded utility poles and power cables compared to other developed countries. Let’s explore the real reason behind this.

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Table of Contents

Frequent Earthquakes

Japan is one of the most seismically active countries in the world. Overhead lines are easier, quicker, and cheaper to inspect and repair after earthquakes compared to underground cables, which can be difficult to access if the ground shifts or collapses.

It is known that during a disaster, overhead power lines are easier to repair after an earthquake because the damage is visible and easily accessible. If underground lines are damaged (especially by liquefaction, as seen in the Christchurch earthquakes in New Zealand), locating and repairing them can be extremely difficult and time-consuming, sometimes requiring extensive digging through rubble.

However, it’s also acknowledged that toppled poles can block roads and hinder emergency response, and modern underground lines are designed to be more resilient to seismic activity. So, while not a definitive reason to avoid undergrounding, it’s part of the complex decision-making.

Japan is highly prone to earthquakes. In the next 25 years, there is a 70% chance that a magnitude 7 earthquake will hit the capital area and nearby regions. It is similar to the 6.9 magnitude quake in 1995 that killed over 6,000 people. If such a major earthquake strikes Tokyo, utility poles could worsen the destruction. Collapsed power poles may spark large fires and block emergency vehicles from passing through the city.

While earthquakes can damage both above and below-ground infrastructure, above-ground lines are often seen as easier to repair after a disaster, as the damage is more visible and accessible.

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Post-War Reconstruction

After World War II, many Japanese cities were devastated by bombing. The priority was rapid reconstruction as Japan experienced rapid economic growth and urbanization. Overhead lines were by far the fastest and cheapest way to restore electricity to homes and businesses. What was initially intended as a temporary solution became the established norm due to its efficiency in rebuilding. This established a de facto standard that persists today.

Cost-Effectiveness

The most significant reason is cost as there are some advantages of overhead transmission over underground transmission. Installing underground power lines is significantly more expensive than overhead lines, typically 4 to 10 times more for transmission lines and 2 to 6 times more for distribution lines. This involves extensive digging, conduit installation, and specialized insulated cables. Japan’s terrain (often rocky and with high water tables in coastal areas) can make excavation even more costly.

While overhead lines are more susceptible to damage from external factors (like wind, snow, falling trees), locating and repairing faults is much quicker and easier. Technicians can visually inspect lines and make repairs in hours. For underground lines, locating a fault can take days or weeks as it often requires digging up large sections of the street. Hence, it leads to longer power outages and more expensive maintenance and repairs.

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Will Japan Get Rid of the Ugly Cables in the Future?

Utility poles in Japan often carry more than just electricity. They also house communication cables (internet, phone, cable television). Additionally, these poles serve other civic functions, providing locations for streetlights, traffic signs, and even address markers, which are particularly helpful in Japanese towns where many streets lack formal names.

Once an infrastructure is in place, replacing it is a massive undertaking. Despite government initiatives over the past few decades to promote undergrounding, the sheer scale of the existing overhead network makes rapid change difficult.

Some argue that the “chaotic” aesthetic of overhead lines has even become an iconic part of the Japanese urban landscape and culture for some residents, sometimes even appearing in anime and other media.

Despite the challenges, the Japanese remain determined to move forward. Makoto Imabeppu, a manager at TEPCO’s power grid unit, stated, “In our view, the current situation no longer allows us to say we won’t do it just because of the cost.”

A budget of $6.8 billion has been allocated to TEPCO (Tokyo Electric Power Co. Holdings Inc.) to remove hundreds of thousands of utility poles across Tokyo. TEPCO is the same company that spent $144 billion on the cleanup after the Fukushima nuclear meltdown in 2011. Currently, TEPCO is laying about 100 kilometers of underground cables per year.

Yuriko Koike, the Governor of Tokyo, said in a speech to parliament that she wants to reduce the number of utility poles in Tokyo to zero.

The Tokyo Metropolitan Government plans to bury between 916 km and 1,442 km of overhead power lines throughout the city. Japanese cities often have very narrow streets and closely packed buildings, making excavation for underground lines difficult and disruptive. One big issue is that 15,000 more over-ground poles are added in the city each year.

Despite major challenges such as transportation, installation, and the fact that underground cables cost ten times more than overhead lines, Imabeppu of TEPCO said, “We still believe we can achieve the zero-pole goal in the near future.”

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Why Japan Uses Overhead Power Lines Instead of Underground?