As countries worldwide develop their renewable energy capacity, governments are exploring innovative ways to transport electricity across borders to promote energy sharing. One way that’s becoming increasingly popular is the undersea cable, which is used to transport electricity under the sea from one country or region to another. There are several large-scale projects already underway in Europe and we can expect this technology to soon extend to other parts of the world, supporting a global green transition.
Recent estimates suggest that the submarine power cable market size could surpass $32.86 billion by 2032and grow at a CAGR of 8.5%, having previously been valued at $14.6 billion in 2022. The demand for undersea power cables has increased significantly in recent years as governments and private companies look for ways to reliably and efficiently transmit power across long distances. Many are connected to offshore wind farms, island power systems and across borders, and the market is expected to grow substantially more, based on the massive global renewable energy pipeline. The growth of the offshore wind sector will support sectoral growth, while governments are increasingly in favour of cross-border power sharing to accelerate the green transition.
In recent years, greater investment in research and development has resulted in the creation of stronger, more efficient subsea cables, capable of carrying power over longer distances. This is attracting even more investment to the sector and encouraging companies to pursue power-sharing agreements. Subsea cables are expected to continue improving in terms of performance and capacity over the coming decades, which will support the expansion of the renewable energy industry.
Nonetheless, there are substantial challenges facing the market, including high installation and maintenance costs, which often deter developers from investing in the technology. Further, there are environmental concerns over the manufacturing of the cables and worries over their impact on marine life. Due to their positioning under the sea, it can also be difficult to access and repair the cables.
Undersea cables have become more popular since the development of the first offshore wind farm in Europe in 1991, this resulted in a shift in cable technology to be focused on power transportation. The international standard IEC 60288 sets the regulatory standards for all subsea cable installation. These cables typically carry alternative current (AC) for short-distance power transportation and direct current (DC), which offers improved electrical efficiency, for longer distances. AC cables are usually used for distances of 80km or less, while DC cables can extend for more than 700km. The cost of submarine cables varies quite a bit, with communication submarine cables typically costing between $30,000 and $50,000 per km and submarine power cables costing over $2.5 million a km.
The U.K. recently approved a power grid project worth over $2.27 billion, which will see the construction of a 190km subsea electricity superhighway aimed at transporting power from Scotland to the north of England. This is part of the National Grid and Scottish Power’s collaborative efforts to develop the $3.16-billion high-voltage power line along the east coast of the country from East Lothian to County Durham from 2025. The Eastern Green Link 1 (EGL1) project is expected to be capable of transporting enough clean electricity to power two million households once complete.
The U.K. government has made ambitious clean power pledges in recent years, and as the country’s electricity demand is expected to double by 2040, there has been increasing pressure on the government to invest in the grid. Recent estimates suggest that the U.K. would have to put over 100km a day of electric cabling in place between now and 2040 if it hopes to meet its climate goals. The national grid says it will need to quadruple the number of undersea cables to respond to the growing demand for power. Peter Roper, the project director for EGL1, stated that the super-cable would be “a transformative project for the UK, enhancing security of supply and helping to connect and transport green power for all customers”.
As well as expanding its domestic power transmission capabilities, the U.K. is also working with other countries to boost its clean energy capacity. In December, Denmark hopes to launch its Viking Link subsea cable, which will transport clean wind energy from Denmark to the U.K. Once fully operational, the link will have a capacity of up to 1,400 MW. The Danish transmission system operator (TSO) Energinet is managing the Viking Link, which is thought to be the world’s longest electricity interconnector. Once a pilot phase is complete, Energinet will boost the capacity from an initial 800 MW.
Denmark already has connections with neighbouring Sweden, but it looking to develop more ambitious clean energy transmission projects over longer distances. The Viking Link could, therefore, offer a blueprint for other countries to follow. Meanwhile, significant investment from National Grid is expected to establish the U.K. as an example for clean subsea cable energy transmission, which could encourage the development of similar systems in the U.S., where National Grid also operates.
By Felicity Bradstock for Oilprice.com
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