Like Internet Cables Covering Land... The Era of Submarine Cables 'Approaches' [Tech Talk]

Ultra High Voltage Direct Current (HVDC) Submarine Cable
Gaining Attention as Eco-Friendly Energy Increases
UK, Australia and Others Also Commission 4000km Project

With the advent of the high-speed internet era, we experienced a boom in 'undersea internet cables' from the 1990s to the early 2000s. Although the cable boom has temporarily paused as the telecommunications industry has matured, it may once again take off. However, this time, the demand is more likely to be driven by 'power lines' rather than communication lines.

Thousands of Kilometers of High-Voltage Power Lines Laid Under the Sea

Export submarine cable of Korean company LS Cable.

On the 21st of last month (local time), Australian IT company Atlassian announced that it had received approval from the Australian government to construct an undersea power cable spanning 4,000 km. This cable will start from the Australian coast and connect to Singapore. As a result, solar power generated from vast solar panels installed on Australia's plains will be supplied to Singapore.

The expected completion date is currently projected for 2029. If this project becomes a reality, it will be recorded as the longest power transmission system in human history. A 4,000 km-class transmission network project is also underway in Europe. The 'Xlink' project, which aims to connect a 4,000 km undersea cable between the UK and Morocco, is in operation to integrate the UK's wind power facilities with Morocco's solar power facilities.

To Succeed in Eco-Friendly Transition... 'Intermittent Energy' Must Be Transferred

The downside of eco-friendly power generation facilities such as wind and solar power is that they are sources of 'intermittent energy.' In other words, they achieve maximum efficiency only on days with strong winds or intense sunlight, while power generation drops sharply during bad weather.

Therefore, in the era of eco-friendly power generation, 'demand control' becomes more important than power supply. Integrating power generation facilities of countries thousands of kilometers apart is part of such demand control plans. When country A lacks power, it can draw electricity from country B, and vice versa.

However, previous transmission technologies would not have been able to build such vast transmission networks. Thanks to advances in High Voltage Direct Current (HVDC) technology, constructing transmission networks spanning thousands of kilometers has become possible. HVDC is a technology that converts alternating current (AC) power into direct current (DC) for transmission, then converts it back to AC at the destination to supply homes and other facilities. It is optimized for transmitting electricity over long distances.

The 4,000-scale submarine cable project 'Xlink' operating between southern England and the coast of Morocco [Image source=Captured from YMorocco]

HVDC itself existed as early as the 1950s, but at that time, it was too rudimentary to realistically envision large-scale inter-country power transmission. However, the latest generation of HVDC currently manufactured can transmit up to 1.2 gigawatts (GW) of power through a single cable, with power loss of about 3% per 1,000 km.

Continental countries like India have already installed and are using 'electric highways' spanning 1,000 to 2,000 km, and the UK-Morocco and Australia-Singapore projects plan to double that scale.

Will Undersea HVDC Experience a Boom Like 'Internet Cables'?

If the Australia-Singapore transmission network and the UK-Morocco Xlink succeed, the 'integration of transmission networks' among countries equipped with eco-friendly energy facilities will trigger a boom. For instance, the UK plans to build offshore wind farms with a capacity of up to 50 GW by 2030, and the European continent is considering 100 to 150 GW.

The undersea power cable boom may resemble the 'internet cable boom' of the early 21st century. From 1999 to 2020, the length of undersea communication cables laid worldwide more than doubled. Notably, the four major US big tech companies (Google, Meta, Microsoft, Amazon) controlled 50% of the total investment.

Initially, massive investments in communication cables were made to globalize the internet, and in the 2010s, these companies entered the communication cable business directly to handle the demand for cloud data transmission.

The HVDC cable business is also growing rapidly, but it has not yet reached the explosive demand growth level experienced by internet cables in the early 21st century. However, as eco-friendly energy becomes the main power source for humanity, this may finally lay the foundation for a leap forward.