Increasingly, as Singapore’s green plan takes shape, the city-state is likely to tap renewable power from neighbouring countries with subsea power cables. In addition, Singapore is a communications hub as it is the landing point of 26 optical fibre cables.
To take a step back, Singapore’s green plan involves producing 2 gigawatts (GW) of solar energy at peak by 2030 and importing 4GW of low-carbon electricity by 2035. This would make up around 30% of Singapore’s projected electricity supply. Some of the imports are likely to be transported to Singapore from neighbouring countries by high-voltage direct current (HVDC) cables.
While it is possible for Singapore to transmit renewable power like wind energy from Vietnam, hydroelectric power from Sarawak and solar power from Australia via undersea cables to the city-state, there are costs and challenges in undertaking such projects.
In May, Sembcorp announced that energy companies from Malaysia, Singapore and Vietnam signed a joint development agreement to explore the export of renewable electricity from Vietnam to Malaysia and Singapore. Tenaga Nasional (TNB), Petroliam Nasional (Petronas), PetroVietnam Technical Services Corporation (PTSC), and Sembcorp Utilities announced they will evaluate the feasibility of exporting renewable energy from Vietnam to Malaysia and Singapore via a new subsea cable, through the Peninsular Malaysia National Grid, with potential additional firming renewable energy generation and storage.
See also: Opinion: Free electricity can break the climate deadlock
In October, Sembcorp Utilities was granted conditional approval by the Energy Market Authority of Singapore (EMA) to import an estimated 1GW of renewable energy from Sarawak to Singapore. This is likely to be done with an HVDC subsea cable.
Considering Singapore’s target of about 6GW of import power, the successful completion of even one of these projects would represent a significant step change in the country’s carbon emissions profile,
The Sarawak project is more complicated, involving Sarawak, the Federal Government of Malaysia, Indonesia and Singapore, and the lead time for ordering high-voltage underwater cables can be lengthy.
The timeline for bringing Vietnamese wind power to Singapore is expected to be in the 2030s.
Prysmian was engaged to carry out an undersea pre-FEED study for the Sarawak project, with the overall project timeline targeted for the mid-2030s. The subsea cable sector is currently in high demand, driven in part by the rapid growth of global offshore wind projects, which are utilising much of the available high-voltage direct current subsea cable manufacturing capacity.
Prysmian has a large orderbook with a backlog and the timeline for implementation of new projects is likely to be in the 2030s. Contracts awarded this year and next will likely start in another couple of years. Global offshore wind projects are also soaking up production capacity from HVDC subsea cable manufacturers.
Globally, only a handful of subsea cable manufacturers are capable of producing the specific HVDC cables for distances of 100km and above.
The HVDC subsea cables are high-voltage cables made of copper or aluminium for power transmission. Connectivity subsea cables are made from glass fibre for optical transmission, enabling the transmission of high-bandwidth terabytes.
Very few companies manufacture these HVDC power cable systems. There are numerous manufacturers of alternating current (AC) systems, but these are better suited for shorter distances of less than 100km, for instance, Batam to Singapore.
Corporate Monitor, an independent, locally-based research firm, says: “The subsea cable industry is currently experiencing strong cyclical tailwinds. Global demand for digital data and offshore renewable energy connectivity is growing rapidly, driving the need for cable installation and maintenance vessels. However, just like other capital-intensive industries, strong prospects often attract substantial new capacity that tends to come on stream at the same time, leading to a glut.”
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HVDC subsea cable manufacturers
Prysmian, listed on Euronext and in Milan, is arguably the world’s largest manufacturer of subsea cables. The other major power subsea cable manufacturers are NKT, listed on the Copenhagen Exchange; Nexans, which was privatised earlier this year; and Sumitomo Electric Industries, listed on the Tokyo Exchange.
Both Prysmian and NKT have announced order backlogs. On Oct 30, Prysmian CEO Massimo Battaini told analysts that the company’s transmission backlog was EUR16 billion ($24 billion) and it clinched EUR3 billion more orders in 3Q2025. Transmission grew 40% in 3Q2025, bringing the nine-month growth rate to 40%.
In addition, the ebitda margins during 3QFY2025 were 18%, a goal that had been set for 2028. Prysmian’s trailing 12-month free cash flow amounted to just under EUR1 billion, due to large down payments and milestones, despite additional investments.
As of the end of June, NKT’s 2QFY2025 order backlog was EUR10.1 billion. To get an idea of the backlog and future orders, NKT continued to invest in high-voltage capacity, including a new high-voltage production facility in Karlskrona, Sweden; the new cable-laying vessel, NKT Eleonora; and additional capacity in the high-voltage factory at Cologne, Germany. These are expected to be operational from 2027. Additionally, as a result of the investment, NKT reported negative free cash flow for 1HFY2025 ended June.
These companies are crucial for power transmission, including renewable energy, as the technology and installation of cables are complex and require specialised expertise. The projects are lengthy, and market observers often point out that banks may only lend for projects that utilise HVDC cables manufactured by this select group.
Take NKT, which has signed a contract with Danish energy company Energinet to deliver a HVDC power cable system for the offshore interconnector linking the Bornholm Energy Island to the power grid on Zealand. NKT was selected because of its technology. The project uses a specific NKT 525kV HVDC onshore and offshore power cable system.
Platforms and cables
A key cog in the HVDC wheel is none other than Seatrium. In 2024, Seatrium and GE Vernova announced they had won a third contract by TenneT TSO BV for the construction of a 2GW HVDC electric offshore transmission system in the Netherlands. The project started in June 2024, with commissioning expected by 2031.
A framework cooperation agreement signed in 2023, when Seatrium was still part of Sembcorp Marine, covers a period of five years with an option to extend for an additional three years. It consists of three contracts, each valued at approximately EUR2 billion, to supply the HVDC electrical transmission systems for three mega offshore wind farm projects, with a combined capacity of 6GW in the Netherlands.
“Seatrium’s contracts for the 2GW HVDC Offshore Converter Platform were awarded through a tender process conducted by TenneT. We are part of a consortium with GE-Vernova for this project, operating under the five-year Framework Cooperation Agreement with TenneT that the Seatrium-GE Vernova consortium announced in March 2023,” says a Seatrium spokesperson.
Each project, IJmuiden Ver Beta, IJmuiden Ver Gamma and Nederwiek 2, is valued at approximately EUR2 billion, she confirms.
“The current contract is for Nederwiek 2, TenneT’s third project with the consortium. The contracts for IJmuiden Ver Beta and IJmuiden Ver Gamma were awarded to the consortium in March 2023,” the spokesperson says, referring to an announcement made by Seatrium in June last year.
The HVDCs are currently at different stages of progress: the first two are currently in the construction phase, while the third is scheduled to begin construction soon. “Our scope of work includes engineering, procurement, construction, installation and commissioning (EPCIC), with each offshore convertor platform (OCP) weighing approximately 30,000 tons,” she explains.
According to a Seatrium press release, the three 2GW HVDC OCPs are the largest and most powerful of their kind in the industry. The platforms will contribute to TenneT’s sustainability ambitions through its offshore grid development programme, which involves the installation of 40GW of offshore wind energy in the German and Dutch North Seas, enabling Europe to become the world’s first climate-neutral continent.
The OCPs will be progressively installed to serve the IJmuiden Ver Beta, IJmuiden Ver Gamma and Nederwiek 2 grid connections. The IJmuiden Ver projects are located approximately 62km off the coast of the Netherlands, while the Nederwiek 2 project is located approximately 95km off the coast.
Construction of the OCPs, each comprising a 25,500-tonne topside and a 9,500-tonne jacket foundation structure, started in 3Q2024 in Seatrium’s Batam and Singapore yards.
A Seatrium subsidiary based in the UK will be performing the offshore hook-up and commissioning. This will include the provision of logistics and warranty support from its base in the UK, as well as the establishment of a European office in the Netherlands.
In the German and Dutch North Seas, Seatrium is currently constructing an HVDC OCP for the Sofia Offshore Wind Farm and an HVDC platform for the DolWin 5 Offshore Wind Farm. Completion of the offshore platforms is expected from 4Q2029 to 2031.
The fundamental difference between offshore converter platform cabling and subsea cabling lies in their installation locations and the connections they facilitate. OCP cabling is installed on the OCP and connects the platform’s internal equipment and systems to the onshore grid.
Subsea cabling is laid on the seabed, connecting offshore wind turbines to each other and to the platform, or carrying electricity from the platform back to shore. OCP cabling is above water and internal to the platform, while subsea cabling is underwater and links the offshore assets together or to land.
Connectivity cables
Alcatel Submarine Networks (ASN), which was privatised a few years ago, and SubCom, which was acquired in 2024 by the New Jersey Fire Exchange from a private equity firm, manufacture connectivity cables.
SubCom designs, manufactures, and installs undersea fibre-optic cable systems. The company has played a strategic role in US national security efforts, including covert cable-laying missions for military bases and installations.
According to the Submarine Telecoms Report 2024–2025, ASN has several major projects planned for 2024–2027, including the Bifrost Cable.
Aaron Bateman, assistant professor of history and international affairs at George Washington University, writing in the July issue of Bulletin of the Atomic Scientists, points out that more than 550 submarine cables, stretching in excess of 1 million km along the seabed, serve as the information highways for both civilian and defence organisations.
“Submarine cables are the physical infrastructure of global connectivity. The same cables that connect billions of users to the internet also transmit sensitive defence-related messages. The fact that cables are lengthy, immobile, and land at fixed points complicates efforts to secure them against both intentional acts of interference and accidents,” Bateman writes.
As the world connects digitally, subsea cables, their manufacture, upkeep and servicing have become integral to the tech sector and for the trillion-dollar data centre and AI industry. Subsea cables have increasingly become focal points of national security discussions. Once considered solely as commercial assets, they now play a critical role in geopolitics, particularly as they are responsible for the vast majority of global communications, including financial transactions, internet traffic and military operations, notes the Submarine Telecoms Industry Report.
Bateman says in Apac, economies such as Japan, South Korea, Australia, Taiwan and New Zealand all rely on subsea cables for connectivity with the US. Singapore itself is the landing point for more than 26 subsea cables, which is why it is so valuable as a data centre hub. According to the Centre for Strategic and International Studies (CSIS), at least 13 additional cables are “in the works” for Singapore.
Most recently, Keppel, along with its partners, has completed installing the ASN-manufactured Bifrost Cable System across the Pacific Ocean. No surprise then that Keppel is likely to be increasingly focused on the subsea fibre-optic cable value chain. Keppel Infrastructure Fund and Keppel Infrastructure Trust (KIT) are set to be the new major shareholders of Global Marine Group (GMG) following an EGM held on Nov 11.
GMG is focused on fibre-optic cables, with very little involvement in power cables. It owns six vessels involved in the installation and maintenance of fibre-optic cables, which contributed 55% of the company’s revenue in FY2024. OceanIQ, a GMG unit providing advisory and consultancy services for both subsea fibre optic and power cables, contributed just 2% to FY2024 revenue. Activist investors are questioning the relevance of GMG to KIT’s portfolio, arguing that its ageing fleet will be outflanked by new vessels.
Subsea cables, whether power cables or data-carrying fibre optic cables, are the unseen intermediaries connecting our lives to those of others around the world, enabling companies to collaborate. Ensuring the maintenance and security of these cables will help the world stay open for business.
