Dynamic cables – Opening up new markets in offshore wind development

Did you know that 80% of the total ocean space is too deep for conventional offshore wind farms?

As wind energy takes on a greater role in providing sustainable electricity to millions, harnessing stronger and more consistent winds found farther offshore is critical. In recent years, advancements in high-voltage (HV) dynamic cables, critical to transporting energy back to land, are opening up new opportunities for offshore commercial wind power.

Harnessing wind power in areas previously impossible

A vast, untapped potential lies in harnessing offshore wind power. Although fixed-bottom wind projects currently lead offshore generation, nearly 80% of the world’s offshore wind potential is in waters deeper than 60 meters. This offers a tremendous challenge for the electrical transmission industry.

Yet, during the past thirty years, offshore wind has played an essential role in the decarbonization of energy. According to McKinsey, the growth of offshore wind capacity is projected to reach 630 gigawatts (GW) by 2050, up from 40 GW in 2020.

Since deeper waters are common along most coastlines worldwide, floating offshore wind turbines are crucial for these regions to harness offshore wind energy. Thus, floating offshore wind offers many countries and regions a viable path to electricity decarbonization. But getting this energy back to shore requires robust HV dynamic cables that can withstand the harsh conditions of the seas.

From sea to shore: How tech breakthroughs are powering up floating wind farms

One of the many advantages of placing wind turbines further out from the shoreline is the sheer power of the winds. More powerful and consistent wind speeds equate to a more reliable energy source.

Turning this powerful wind into sustainable energy is possible in part due to new developments in HV dynamic cables and enhancements in floating wind turbines and substation designs.

And it is thanks to these advances that by the end of the decade, large-scale floating wind farms on the West Coast of the United States, France, and South Korea will finally be a reality.

And we’re already seeing this happen. The first commercial floating wind project to be awarded is in France, off the coast of Southern Brittany. This monumental project will, upon completion, be the largest floating offshore wind farm in the world. The 250 MW site will double Europe’s current floating offshore wind capacity.

However, reaching this milestone requires getting the energy back to land where it can be transmitted and used. And this is where HV dynamic export cables are the critical link. To do that requires cables that can withstand deep-water seas. A feat that has taken years to achieve!

Overcoming new challenges going forward

The oil & gas industry has a long history of using medium voltage (MV) electrical subsea equipment. Today, that same philosophy is being explored for subsea substations. However, HV systems are a different playing field!

Transitioning to HV subsea equipment brings in a lot of additional challenges due to both increased voltage and larger sizes. This generates new challenges for design and handling offshore, combined with even more strict requirements for design tolerances and water tightness.

All HV subsea systems, including cables and potential substations and their connectors, require significant testing and qualification efforts over long time spans. Often, new failure modes arise as we acquire more knowledge about higher-voltage subsea equipment.

When it is possible to install subsea offshore substations or converter stations on the seabed, it will be a game-changer. It will unlock vast new areas for wind energy production, improve efficiency, and contribute significantly to the transition towards a sustainable energy future. For example, this advancement will significantly enhance the cost efficiency of electrical export, ultimately reducing costs and optimizing resources.

Growth of floating wind farms in the years to come

The vast open seas hold great potential in the world’s quest to decarbonize electricity. Floating wind farms, farther out and deeper, will play an increasingly important role in the battle against climate change.

Major advancements in HV dynamic capabilities play a critical role in achieving the commercial success of floating wind farms. Nexans’ groundbreaking 145 kV dynamic cable capable at 1300 meters opens up new opportunities for deep sea projects in harsh water conditions. This innovation is crucial for the future of commercial floating wind farms.

According to an August 2023 Global Wind Energy Council (GWEC) report, the floating wind market will accelerate by the end of the 2020s, with 11 gigawatts (GW) installed by 2030 and 26 GW by 2032.

Starting in 2031, floating wind installations will constitute over 10% of annual offshore wind installations, a notable achievement given the rapid expansion of offshore wind overall.

This growth will significantly contribute to adding decarbonized electricity generation to power grids, supporting global efforts to reduce carbon emissions, and the transition to sustainable energy sources.

Power grids are undergoing a monumental transformation. Driven by the energy transition, vast offshore wind farms are sprouting across the globe, promising a more sustainable future.

Connecting these remote parks to the mainland grid requires a crucial but often overlooked hero: the submarine power cable.

Imagine these cables as the silent arteries of the energy sector, carrying enough electricity to light entire cities. Their importance is undeniable – a single high-voltage cable tripping can put energy security at risk.

These underwater giants, stretching for hundreds of kilometers, face a unique set of challenges. Unlike their above-ground counterparts, they’re largely hidden from view, making proactive maintenance a critical and complex task.

Yet, recently, a declaration announcement emanating from six North Sea countries and NATO has emphasized the significance of infrastructure security and robustness.

This is where cable monitoring comes into play.

Monitoring of subsea cables: 3 main challenges

Due to the increasing reliance on offshore power sources, grid operators are being faced with changes and challenges. Here’s a closer look at some of the key concerns:

1. The end of a decentralized past

Traditionally, cable health data was scattered across individual local control rooms and equipment, making it nearly impossible to get a holistic view of the system. It was like having ten different doctors analyzing your health, each with their own reports and interpretations.

Thankfully, the tide is turning. We’re witnessing a shift towards centralized platforms that consolidate data from various sources, offering a comprehensive view and enabling faster, more informed decision-making.

2. The data deluge: Making sense of the noise

But the journey to a truly robust monitoring system isn’t without its obstacles. One major hurdle is the sheer volume of data generated by an array of sensors. Imagine being bombarded with continuous data streams from a thousand sensors – how do you identify a subtle change that can lead to a threatening event?

Another hurdle arises from the fragmented nature of the monitoring landscape. Different vendors often use proprietary technologies, making it difficult to integrate data from various monitoring systems. This creates a tangled web of information, hindering efficient analysis. The ideal solution lies in open platforms that seamlessly integrate with diverse monitoring technologies, providing a unified view of cable health.

3. The limitations imposed by longer interconnections

Subsea interconnectors, the power cables linking distant grids across vast stretches of ocean, pose a unique challenge for traditional monitoring techniques.

Take, for instance, the ambitious Great Sea Interconnector project, a planned high-voltage cable stretching a staggering 900 kilometers to connect the power grids of Greece and Cyprus.

At such immense distances, conventional monitoring methods using optical fibers suffer from signal attenuation – essentially, the message gets weaker as it travels, making it harder to detect issues.

To overcome this challenge, the integration of technologies akin to those used in transoceanic cables, such as amplifiers, is essential. Amplifiers can boost the signal strength at regular intervals along the cable, ensuring that monitoring systems maintain accurate and reliable communication.

5 advanced techniques for subsea cables monitoring

Thankfully, the world of cable engineering can count on plenty of solutions. Here are some of the cutting-edge technologies playing a vital role in safeguarding the health of subsea power cables.

Monitoring and the revolution of artificial intelligence (AI)

Of course, AI is among the most promising revolutions for the monitoring of subsea cables.

Indeed, the sheer volume of data generated by advanced monitoring systems can be overwhelming. This is where AI steps in, helping to:

• Filter Out Noise and Identify Threats: By analyzing complex data patterns, AI can effectively distinguish between background noise and real threats. This ensures that operators focus their attention on the most critical issues.
• Predictive Analytics: AI can leverage historical data and real-time sensor readings to assist in identifying potential problems before they even occur. This allows for preventative maintenance and minimizes downtime.

The road ahead: Monitoring powered by constant innovation

Imagine a user-friendly cockpit that displays real-time data, analyzing failure modes, and proposing remediation actions for all your cable assets in single place: this, in essence, is the future of cable monitoring.

Comprehensive cable monitoring solutions are paramount. A centralized approach not only simplifies cable management but also empowers operators to make informed decisions quickly and efficiently.

Nexans, at the forefront of these innovations, has developed a solution that isn’t just an abstraction layer: it is a versatile data platform, with state-of-the-art digital frameworks, intuitive dashboard and harmonized analytics that brings the cable data management to the next level. It integrates information from various sources and presents a clear picture of the network’s health.

Built to scale, it adapts seamlessly to the growth of the grid. Whether through on-premise deployment or cloud-based access, this solution offers flexible options. Prioritizing cybersecurity, the platform utilizes the latest technologies and maintenance processes to safeguard critical data.

The energy transition depends on the silent guardians of the grid – subsea power cables. As we harness the power of offshore wind farms, robust cable monitoring becomes an indispensable tool. By overcoming the challenges of data management, signal interpretation, and technological fragmentation, we can ensure the health and longevity of these critical underwater connections.

Innovative monitoring technologies can help the silent heroes under the sea to continue to play a vital role, ensuring the lights stay on and our cities vibrate with sustainable energy.

Electrification, particularly from renewable sources, is playing a pivotal role in the world’s quest for net zero emissions. And as we move towards a more electrified future, it’s crucial to acknowledge the environmental impact of the very cables that power our lives.

The demand for subsea cables that can safely and efficiently carry the growing current is surging. As innovative technologies are reaching new heights in their ability to transmit sustainable energy at greater volumes, distances, and depths, ensuring their sustainability throughout their life cycle is equally important.

Let’s dive into the innovations in electrical transmission that are unquestionably promoting this shift.

Subsea cables: the need for a sustainable mindset

But first, there are two reasons why the question needs to be raised.

1. Cables’ components

The environmental footprint of the cables’ materials demands our attention. These are the obvious environmental costs it takes to electrify the future.

Above all, the conductor, which channels the electrical flow, is composed of copper or aluminum and constitutes a significant part of the overall GHG emissions of subsea cables. Much of this is due to the energy required in producing and purifying the metals, which is why it is essential to use renewable energy in the extraction process to reduce the environmental impact.

2. The importance of sustainability in a resource-constrained world

Did you know electrical wire and cable can contain up to 80% copper?

Known as ‘the metal of electrification,’ copper is paramount in the production of cables. The metal is excellent for conducting electricity efficiently: its unique properties allow for a smooth flow of electrons, which minimizes energy loss in transmission lines.

Yet, due to the growing focus on electrification, global copper demand is expected to reach 39 million tons in 2030 (compared with 13 million tons in 1995 and 29 million tons in 2020). And possibly, at the same time, it might become increasingly scarce. Furthermore: its excavation and mining come with its own social and environmental challenges. Co-existence with other industries such as fisheries as well as local communities which might be adversely affected by mining can limit access to potential resources.

Let’s now explore the solutions and innovations that are key to help us mitigate the environmental impact of subsea cables.

The future – moving to a sustainable mindset

Nexans positions itself at the forefront of this impetus. For example, the Group’s casting facilities in Canada, France, and Peru reused roughly 19,700 metric tons of copper scrap in 2022. In 2008, Nexans and Suez formed the joint venture RecyCâbles as a complete cable recycling solution. Since its inception, it has become a European leader for cable recycling and recovery.

Here are three concrete examples of current innovations that are leading the way:

SF₆ replacement and GIS terminations

Replacing SF₆ as insulating medium in cable terminations, with alternative insulating gases (such as GE’s g³) or with dry-type solutions, is critical. This would reduce the GWP, with more than 99 percent, in any event of accidental gas emission. Converter manufacturers are also currently developing switchgears using alternative gas to SF₆, so this gas can be substituted in the complete HVDC cable systems.

The advantage of using GIS terminations is twofold, because GIS terminations also allow a major reduction of space needed in the offshore converter stations, which leads to significant reduction of converter platform size, and consequently of steel used for its construction.

The OceanGrid Project

Innovative research initiatives are instrumental in seeking more sustainable and viable interconnectors. With the OceanGrid Project, research is being carried out on a new aluminum alloy aiming to advance the deployment of profitable offshore wind farms in Norway in 2030 – 2050.

The AluGreen consortium

In the AluGreen consortium, Nexans leads the exploration of introducing end-of life conductor materials in new subsea cables. The consortium draws from the full aluminum value chain in Norway which sets the stage for piloting full circular business models.

The world is electrifying, and the cables that carry this energy surge need a sustainable upgrade.

Subsea cables are crucial for efficient transmission of renewable energy offshore. Yet, they can have a significant environmental footprint.

Traditional materials and production methods create challenges; however, innovation, from recycling to new technologies, is paving the way for a more sustainable future.

Imagine a giant sea serpent made of copper and steel, winding along at a depth of 3,000 meters under the sea. No, it’s not a mythical sea creature, it’s an interconnector cable!

You are no doubt already familiar with subsea fiber optic cables, the technology making it possible for you to read this article. Yet the underwater depths also host far larger cables, able to transmit electricity from one country to another.

What is an interconnector?

Routed under the sea, these high-voltage cables play the role of invisible highways, taking electricity from one country to another.

They measure up to 300 mm in diameter and can weigh up to 140 kg per meter… for a total weight of up to 9,000 metric tons! We’re talking here about gigantic structures that can weigh as much as the Eiffel Tower.

To imagine what’s inside, think of a big sushi: the cable body is made of copper and sometimes optical fiber, protected by an armor of thick steel.

These subsea cables are manufactured in ultra-modern plants, able to assemble the various components with millimetric precision. They are then transported on cable-laying vessels, which deploy them on the seabed.

This operation is a real technological feat, making it possible to transfer power across seas and oceans, in order to support the energy transition.

What are the advantages of subsea interconnectors?

Let’s just take a step back in time: the first interconnections between national power grids took place two decades after World War Two.

Today, Europe is the most advanced continent in terms of interconnections. Its highly sophisticated network relies in part on these subsea cables.

A fast-growing interconnection market

It is no surprise to see the offshore wind and interconnection markets expanding at a rapid pace. Major investments will be needed wherever the level of interconnection remains insufficient.

Subsea cables are becoming an increasingly common choice, not only in America and Europe, but also elsewhere in the world. In September 2023, for example, the grid operators of Greece and Saudi Arabia signed a strategic agreement setting up ‘Saudi Greek Interconnection”, a joint venture to link their power grids.

So, in short… Subsea interconnection cables are invisible giants, energy highways winding along the seabed.

As such, they have a crucial role to play in the global energy transition: enabling the exchange of electricity between countries, promoting the integration of renewable energies, securing supplies and contributing to lower prices.

These cables represent both a technological feat and a colossal level of investment. Their development is part of an ongoing dynamic. Subsea cables are a key part of efforts to address climate change and to build a more sustainable energy future.

Renewable sources of electricity become an increasing and exceedingly important factor in the energy equation. Global annual renewable capacity additions increased by almost 50% to nearly 510 gigawatts (GW) in 2023, the fastest growth rate in the past two decades, marking a major step forward in the reduction of fossil fuel power. Moving to renewable energy is vital to decreasing greenhouse gas emissions and aligning with the 1.5 Celsius climate target set in the Paris Agreement.

Even as renewable energy generated a record 30% of global electricity in 2023, furthering the growth of renewable energy relies heavily on grid interconnection.

Interconnections provide the optimal way to ensure energy security across regions and continents:

• When grids are interconnected, surplus energy from one region is easily transported- via the interconnected power grid – to where electricity is needed. This ensures energy security across the interconnected grids and avoids reliance on fossil fuels when renewable energy cannot meet local demand.
• By equalizing demand and supply across interconnected grids, excess power is more readily available to areas with increased demand, thus ensuring energy price stability and future renewable investments.
• The harnessing of electricity across grids goes beyond adjacent regions to include the interlinking of power grids across continents and islands and offshore renewable energy sources. Deep water, once a barrier to interlinking grids, is less of an issue thanks to innovations in cable design, new materials and alloys, and cable installation and maintenance advancements.

1. Deep sea grid interconnections – from megawatts to gigawatts

The interconnection of grids is not only reaching impressive depths, but their capacity has also gone from hundreds of megawatts to gigawatts.

To date, the deepest installed HV cable system is the SaPeI interconnector, stretching 435 kilometers, linking Sardinia and mainland Italy, reaching 1,640 meters below sea level.

One revealing example of this revolution is the Tyrrhenian Links project, currently under construction. It will connect Sicily with Sardinia and the Italian peninsula. It will be installed at a record-breaking 2,200 meters deep, for a transmission capacity of 1,000 MW. Achieving this is possible thanks to advances in high-voltage direct current (HVDC) systems, which can transmit larger amounts of power over long distances.

If this technology is already available for shallow waters, engineering challenges arise when increasing the water depth.

2. Mass-Impregnated (MI) undersea cables – decades-long reliability track record

Mass-impregnated cables’ first commercial use was in 1954 for the Gotland HVDC Link to connect the Island of Gotland to mainland Sweden. Since then, mass-impregnated cables have been the primary choice for subsea HVDC interconnector projects requiring voltages surpassing 500 kV over long distances and extreme depths.

Simply put, a MI undersea cable is a type of HVDC cable specifically designed for underwater applications. Here is the breakdown:

• Construction: it is made with layers of high-density paper tapes wrapped around the conductor. These tapes are then impregnated with a special, high-viscosity compound. This compound is key – it’s thick and doesn’t flow easily, even if the cable is damaged.
• Application: it is used for transmitting large amounts of electrical power over long distances underwater. They are particularly useful for applications exceeding 500 kV DC and long distances.

MI cables offer three main advantages that make them innovative for undersea applications:

1. Reliability: The high viscosity compound prevents leakage even if the cable is damaged, making it more reliable for underwater use compared to older designs.
2. Durability: cables installed decades ago are still operational today, demonstrating their long lifespan.
3. Depth capability: they can be used for extreme depths with proper design features.

Overall, MI cables are a well-established and trusted technology for transmitting large amounts of power underwater, making them a key innovation for subsea power transmission.

Breaking even new barriers to deep sea cable depths will be the Great Sea Interconnector project. Reaching depths of up to 3,000 meters in some areas, the project will connect Israel, Cyprus, and Greece via Crete. Stretching 900 kilometers from Crete to Cyprus, the 1,000-megawatt, bi-pole cable will bolster energy security and facilitate electricity exchange between the countries.

3. Overcoming subsea cable challenges – new design approaches

The main challenge in using MI technology in subsea cables however is the elongation of the insulation system during deployment and retrieval.

There are many ways this can be overcome. The most prominent is through cable design, conductors, materials, or installation methods.

Additionally, 500+ kV extruded cable designs are also being developed. A major advantage of extruded cable design is its ability to sustain greater elongation compared to MI cables. A challenge for extruded design is the need for effective water blocking in the conductor in the case of damage to the cable. At 3,000 meters below sea level, the pressure is so great that if the water is not blocked in the conductor, it can easily penetrate tens of kilometers into the cable, leading to costly repairs.

Nexans is deeply involved in the electrical transmission revolution that is going on.

In fact, the Group has been playing an essential role for a long time. In 1977, Nexans deployed its first HVDC MI cables for the Skagerrak subsea interconnector between Denmark and Norway. Almost 50 years later, the original cable system is still in use. Today, its expertise in building, installing, and repairing deep sea HVDC systems spans MI and extruded technologies.

Its most monumental undertaking is currently crafting the world’s longest and deepest subsea interconnection: The Great Sea Interconnector. This colossal project symbolizes a new era in energy interconnections and demanded immense resources and logistical mastery.

Innovation is the lifeblood of deep sea grids. For this sustainable future revolution to reach its full potential, robust and far-reaching interconnectivity is paramount. Deep sea grid interconnectors are the invisible threads weaving a global energy tapestry. Challenges remain, but solutions are on the horizon.

Deep sea grids are not simply cables on the ocean floor; they are the lifelines of a safer energy landscape. They are the physical manifestation of a global commitment to a sustainable future, a future powered by the boundless potential of renewable energy.

Faster, higher, stronger – together is the motto of the Olympics, but it can also apply to the changes happening in the electricity transmission and distribution industry.

As decarbonization of energy takes on a heightened importance globally, it will take a unified approach to reach net zero by 2050. To do so will mean eliminating fossil fuel combustion and transforming power grids to accommodate intermittent renewable energy.

Rejuvenation of the grid that a decarbonized and electrified world needs differs significantly from the ones built post World War II and on which we still rely today. Modernization and newer storage technologies are crucial in decarbonizing electricity. But equally important are the connections of supply from one electric network to another to ensure energy reliability and stability and transition the world to renewables.

Thus, according to a report published by the International Energy Agency, the world must add or replace about 80 million km of grids by 2040, equal to all grids globally today, in order for countries to meet their climate goals and to achieve energy security priorities. Considering only offshore wind in Europe, 48 000 to 54 000 km of HV cable route length shall be added by 2050 to meet the offshore wind targets of the European countries, according to a ENTSO-E’s TYNDP report published in January 2024.

For decades, experts have discussed interconnections. However, two crucial factors are now driving their escalating importance: the increasing availability of renewables and the vulnerability of today’s network to climate change.

Put simply, an interconnection links a network of grids together at a synchronized frequency. This enables the transfer of surplus energy from areas with excess power to those with higher demand than they can meet locally. Harnessing electricity from a regional grid allows the local network to reduce the risks of power outages or failures, thereby boosting power reliability and stability.

In addition, interconnection links islands and continents to sources where renewable energy generation is more plentiful, thus progressively diminishing reliance on fossil fuels. Examples include the interconnection between Crete to Greece, Mallorca to Spain and Tasmania to Australia. This enables the development of renewable energy sources on these islands, freeing them from dependence on polluting power generation.

Here are five innovations that will make electrical transmission reach new heights.

Interconnections globally are instrumental in ensuring the viability of sustainable energy and reducing the reliance on fossil fuels. Achieving this requires a cutting-edge mindset in designing, manufacturing, and installing deep-sea cables that can transmit increasingly higher energy levels and that can realize interconnexions in previously impossible areas.

Moreover, innovation in electrical transmission is unquestionably linked to unerring monitoring as well as highly sustainable design.

From the engineering, manufacturing, construction, and installation of HVDC cables for connection systems, to the world’s first electrical Type Test with 320 kV HVDC cable termination using GE’s g³ gas to considerably lessen global warming potential, by way of the increasing amount of recycled metals used in cables: Nexans is at the forefront of these innovations.

In the coming weeks, we invite you to deep dive into these innovations that will revolutionize the electrical transmission industry.

Modern transmission and distribution electrical grids are the most complex machines ever built. They span continents and encompass numerous interconnecting components and subsystems—while intricately balancing energy demand and fluctuating supply.

Not only are today’s grids complex, they are mammoth in terms of components and their geographical size. There are over one billion operational smart meters worldwide and the cables and lines stretch across 80 million kilometers. In other words: ten roundtrips between earth and moon!

And this complexity is only expected to grow. According to a newly released IEA report—Electricity Grids and Secure Energy Transitions—to reach climate targets and ensure energy security, 80 million kilometers of power lines will have to be replaced or added by 2040.

As power grids increase in complexity and scope, grid operators are turning to digital twins. While digital twins have been applied for decades by an array of industries, they are increasingly being used to help grid operators make strategic planning decisions, optimize operational performance, and manage risks within the context of unprecedented complexity.

3 factors that made grids so complex

1. As the world transitions from fossil fuels to renewables, grids need a better equipment to handle the variability of energy sources from wind, solar and hydroelectric.
2. The growing threat of severe weather caused by climate change is putting an additional strain on antiquated electric infrastructures globally.
3. 40GW of rooftop solar panels have been installed worldwide in 2022. This massive, fuzzy, intermittent deployment of solar energy injected into the grid has brought major challenges in power quality and load forecast management.

To handle these growing challenges, power grid operators have turned to digitization to improve the operational management of networks. Smart meters and IoT sensors provide operators with valuable data; yet, they add an additional layer of complexity.

Digital twins: From grid knowledge to understanding

With this increasing complexity and the overwhelming flow of real-time data, digital twins are proving pivotal to the operation of smart grids. They are used in order to:

• Simulate ‘what-if’ scenarios to understand, for example, operational outcomes of varying decisions
• Manage and foresee maintenance needs
• Avoid or limit grid downtime
• Help operators present data-backed asset investment plans.

The power of digital twins is their capacity to virtually reproduce the multi-scale interactions and correlations between organizations, thus providing a more holistic view of the grid and avoiding decisions made in silos. This gives decision-makers of any given department, such as engineering, planning, and operations, the ability to stimulate the consequences of various decisions and their impact throughout the organization. As such, calculated decisions are made based on implications, expected outcomes, and trade-offs and not just on past knowledge and experience.

Digital twins are revolutionizing grid management, as demonstrated by the landmark initiative to build a digital twin of Europe’s electricity grid. One of the initiative’s key aims is fostering innovative technologies in the race to ensure the readiness of the electricity grid for the drastic increase of renewable energy and resiliency to future shocks (such as climate and cyber-attacks).

6 key areas where digital twins are revolutionary

There are six key areas where the deployment of IoT-connected instrumentation sensors together with digital twins are providing impactful benefits and value to grid operators.

Digital twins represent a significant paradigm shift in electrical grid management. They facilitate all aspects of the business and operational mission of grid operators. They are paving the way for more reliable, resilient, efficient, and sustainable power grids, thus enabling the industry to meet its ambitions to be at the forefront of the transition to clean and decarbonized energy.

As a key driver to move away from fossil fuels, which are a massive source of CO2 emissions, renewables are an essential part of the future of energy. In this context of race against time to combat climate change, a growing emphasis is put on decarbonization of electricity.

The transition to renewable energy on a large scale is reliant on energy storage technologies. Energy storage is an essential part of the transition to clean energy and the foundation upon which the decarbonization of today’s grids must be built. Due to the intermittent nature of renewable energy — mainly wind and solar — grid operators must rely on energy storage systems to balance supply and demand. This interdependence means that storage is integral to grid resilience and reliability.

It is projected that by 2030, global energy storage installations will reach a cumulative 411 gigawatts (GW), according to the latest forecast from research company BloombergNEF — an increase of 15 times the storage online in 2021.

Other significant factors driving energy storage growth are government policies aimed at curbing increasing energy prices, meeting peak demand, and energy independence. In 2022, the Inflation Reduction Act (IRA) bill was signed into law, representing the U.S.’s largest investment to fight climate change.

Energy storage challenges: the need for widespread grid-scale technologies

A major challenge facing the industry today is the need for widespread grid-scale storage technologies. Today, the most viable solution is pumped-storage hydropower, which generates electricity by pumping water into a reservoir and then releasing it to generate electricity at a different time. Unfortunately, this technology can only be applied in specific locations. As such, grid operators must resort to fossil fuel energy sources to meet peak demand periods.

However, in recent years, advancements in storage technologies are now providing new opportunities for the potential to meet energy fluctuations in energy demand without resorting to fossil fuels. Thus giving grid operators the ability to store excess renewable energy and, to some extent, help balance in real-time energy demand to meet peak periods.

Five renewable energy storage technologies ensuring a reliable power supply

Proper energy storage ensures a reliable power supply as the electricity grid becomes more dependent on variable renewable energy (VRE) sources. What often differentiates technologies are their storage capabilities, reactivity, scalability, and application requirements.

Thermal energy storage: a viable alternative for commercial buildings

The emergence of newer thermal energy storage (TES) technologies is making it a viable alternative in commercial buildings. TES systems can store heat or cold to be used later and are divided into three types: sensible heat, latent heat, and thermochemical. When installed in a building, a TSE solution allows the building itself to act as a thermal battery — storing renewable energy in tanks or vessels to be used when needed.

Superconducting magnetic energy storage: for an instant and efficient release of energy

Superconducting magnetic energy storage (SMES) stores energy in a magnetic field. Because it can release stored energy instantaneously, it is considered ideal for grid applications requiring fast reaction time. Due to its negligible energy losses, there is increasing interest in finding a way to use it in large-scale energy storage applications. A few prototypes are currently in service, mostly under investigation, and they are beginning to be identified as a possible cost-effective solution.

What is the future of energy storage?

New materials and the development and supply of storage batteries for surplus renewable energy are quickly evolving to meet maturing requirements. Newer power electronics can convert stored energy into electricity to provide low to zero-impact solutions.

Nexans contributes in several ways to the energy transition, of which electricity storage is a key element, starting with the supply of transmission and distribution grids for the collection of renewable energy—wind and solar—at the source. It is crucial to collect electricity where it is generated (e.g. offshore wind farms) at an acceptable cost. The integration of storage sites is based on the same connection capacity, whether on a high-power scale or more widely distributed over a region.

Integrating variable renewable energies into smart grids will require an ever-increasing ability to monitor real-time usage requirements alongside automated systems in order to balance demand and supply loads. Faced with the need for greater flexibility, Nexans has developed new services accordingly.

For electric mobility applications, which are highly dependent on the technical and economic performance of electricity storage, Nexans supplies proper cable connections and protections, as for charging stations of electric vehicles, through specific safety functionalities to ensure safe energy storage.

Nexans has also acquired worldwide expertise and leadership in electrical and fire safety, that can be extended to the new applications of storage, such as vehicle batteries as they are becoming increasingly crucial.

The Group has been innovating for decades with industrial cryogenic and superconducting systems, such as with the development of a cryogenic transfer system of liquefied natural gas and hydrogen. As liquid hydrogen is very likely to play a key role in storage, Nexans will continue to innovate with breakthrough technologies to design tomorrow’s electricity grid.

Progress in energy storage technologies is vital to the transition to clean energy and the decarbonization of electricity. In the future, large-scale energy storage technologies will evolve and thus provide smart grids with the ability to reach their full potential. Diversifying and strengthening the supply chain of the new equipment for a massive deployment is a major challenge, especially for critical raw materials in a tense geopolitical context. Innovating by recycling materials used in end-of-life products is already a key driver, for which Nexans has prepared and positioned itself particularly well

As intermittent renewable energy becomes a larger share of the world’s power, grid flexibility will become increasingly instrumental. According to the European Commission Joint Research Center, compared to today, grid flexibility requirements will more than double by 2030 and be seven times as large by 2050.

As clean energy transition advances, grid digitalization will be an enabler alongside flexibility management. In recent years, grid digitalization investments have progressively increased from 12% of total grid investment in 2016 to 20% in 2022, driven by system operators requiring digital solutions to improve the management of the grid with real-time monitoring and control of energy flows for transmission and distribution networks.

Grid modernization is imperative to accommodate the expected electrification growth. Moving away from fossil-fuel-based electricity means that today’s grid must be able to integrate large share of renewable energy resources and address associated technical challenges.

Virtual power plants: The big move for electric generation

A new generation of distributed electricity resources (DERs) is gaining momentum as a way to solve the increasing demand for clean, renewable energy.

Advances in battery storage, EV and solar technology, coupled with the desire of utilities to expand renewable power, mean Virtual Power Plants (VPP) are fast becoming a favored approach to meeting growing electricity demand and the need for more resilient power systems.

A VPP is both a technical and transactional platform connecting a vast number of diverse resources to deliver, in seconds, a megawatt-scale power response to an instruction, reducing complexity for grid operators. In addition to the technical aspects, it provides the transactional flow by remunerating each resource for its contribution to the final service receiving payment from the Transmission System Operator (TSO), Distribution Grid Operator (DSO) or power market upon the available opportunity. Revenue stacking is gaining importance in delivering value to the DERs owners.

Because a VPP can provide power by tapping into the Distributed Energy Resources (DERs)—building blocks of VPPs—it can quickly balance supply and demand, thus avoiding potential power outages and reducing energy costs to the end user. In recent years, VPPs have increasingly been implemented in residential and commercial buildings to attract new buyers and provide reliable, lower-cost electricity. Even consumers can join a VPP. As an example, last year, Tesla launched its new power utility provider service in Texas that lets Powerwall owners sell excess energy back to the grid.

DER: paradigm shift in energy distribution

The distribution grid is facing unprecedented transformation as the growth in DERs increases. This transformation will require new levels of grid management and monitoring. The Advanced Distribution Management System (ADMS) is an essential component of the modern control center. Instrumental will be the digitalization of power flow observability, fault detection isolation and restoration, network reconfiguration and outage management systems. The new challenge of the distribution grid will predominantly be at the low-voltage level, where a greater level of observability is needed and requires the flexibility from DERs. This is where the Distributed Energy Resources Management System (DERMS) complements the ADMS by enabling a grid aware DER flexibility orchestration down to low-voltage level.

Grid digitalization: a journey

To solve the lack of network observability, Nexans is collaborating with Sensewaves to create a computable grid topology for DSOs. Sensewaves’ Artificial Intelligence-based analytics software leverages smart meter data (or other sources) to enhance planning and asset reliability (particularly cable systems) for DSOs. This unique combination of data analytics and AI provides invaluable insights beyond operational management typically offered through the ADMS and DERMS platforms.

Grid modernization is imperative to adapt to the expected electrification growth. Moving away from fossil-fuel-based electricity means that today’s grid must be able to accommodate the interconnection of renewables. New technologies in distributing, transmitting, and managing clean energy will play an instrumental role in reducing carbon emissions.

The necessary transformation of grids, in a context of a world’s transition to renewable energy and of a growing demand for decarbonized electricity, requires an infusion of digital intelligence.

In this context, sensors are essential. They are the ‘eyes and ears’ of the modern power grid, providing invaluable data critical to the reliability, efficiency, and adaptability of tomorrow’s grid data management.

Five sensor data technologies are transforming today’s power grids.

1. Smart meters for an effective energy measurement

Smart meters come in three variations, each with different features:

• Standard smart meters accurately measure electricity consumption and enable remote meter reading, eliminating the need for manual readings. They often support time-of-use pricing, allowing consumers to save money by using electricity during off-peak hours.
• Intermediate models add two-way communication between consumer and utility. They offer load profiling, providing detailed data for optimizing grid operations and load management. They may also support outage detection, helping utilities respond promptly to power interruptions. These meters may incorporate tamper detection mechanisms, alerting utilities of potential electrical energy theft, which can result in important non-technical losses to the operator.
• Advanced meters often support demand response programs, enabling utilities to control or adjust electricity demand remotely during peak times. As power quality sensors become the standard, it will help to identify voltage fluctuations and sags. Grid monitoring capabilities offer insights into the health and performance of the distribution grid, such as low voltage arcing or faults, allowing utilities to take proactive maintenance measures.

2. Single and multi-conductor current sensors

To meet ambitious net zero targets and avoid volatile and rising energy costs, grids must reduce unnecessary energy wastage.

Sarah Marie Jordaan, Assistant Professor of Energy, Resources, and Environment at Johns Hopkins University, says 500 million metric tons of carbon dioxide can be cut by improving global grid efficiencies. These savings represent more than one percent of the worldwide CO2 annual emissions. But as Scottish-Irish physicist William Thomson, better known as Lord Kelvin, wisely said, ‘If you cannot measure it, you cannot improve it.’

Solutions such as single and multi-conductor current sensors are a game changer for process and plant managers. They are field-proven solutions that can be installed directly around conductors and cable feeders to selectively and rapidly deploy audit sessions. They enable installation without operation interruption so as to build concrete energy-saving strategies leading to energy consumption reduction of up to 20 percent.

3. Energy harvesting: converting small amounts of energy from the environment

In remote or challenging-to-access locations, the deployment of sensors poses sustainability and operational expenditure challenges, primarily concerning battery management.

With the industry set to witness over 25 billion connected objects in the sector by 2025, energy harvesting emerges as a pivotal technology to facilitate the expansion of sustainable sensors and Internet of Things (IoT) solutions.

As a concept, energy harvesting involves capturing and converting small amounts of energy from the environment or nearby power sources, such as cables. The most prevalent energy harvesting method is photovoltaic, which transforms light into electrical energy. Cost-effective and customizable for indoor lighting applications, it is an ideal fit for IoT solutions.

Inductive technology is another popular choice for cable systems. It empowers devices to operate independently by harnessing energy from power cores or terminations. This approach offers sensor functionality without the need for maintenance, delivers environmental benefits, and extends the system’s lifespan.

Recent advancements in electronic devices, including processing units and low-power wireless technologies, enhance overall efficiency and thus establish the harvesting approach as a reliable power source.

4. Edge-to-cloud: a revolution in maintenance practices

Edge-to-cloud integration is continuously revolutionizing maintenance practices, making them smarter and more efficient, particularly in the context of power grids.

5. Fiber optics: minimizing power disruptions

Optical fiber can be applied for remote data acquisition or as distributed sensor applications where traditional techniques are impractical or costly to deploy.

The emergence of fiber optic sensing technology is providing grid operators with a more cost-effective and accurate way of acquiring data compared to punctual sensors.

Distributed fiber optic sensing is the ability to continuously measure activity throughout the power grid, helping operators to quickly pinpoint the exact location of potential or actual disruptions and thus minimize or even avoid costly power outages.

Sensitivity of fibers to temperature and mechanical strain offer a comprehensive approach to distributed sensor applications:

• Distributed Temperature Sensing (DTS) enables the early detection of abnormal events such as hotspots and thermal bottlenecks due to condition changes in the surrounding laying environment of the cable. When combined with real time temperature rating algorithm, DTS systems allow to assess the operational condition and circuit power rating, allowing safer operation of the cable to its real conditions.
• Distributed Acoustic Sensing (DAS) offers precise fault detection, localization and third-party interference detection both onshore (e.g., cable theft, digging, and drilling) and offshore (e.g., anchor drops and drags). Thus, providing efficient power cable condition monitoring by listening 24/7 to acoustic signatures.
• Distributed Strain Sensing (DSS) continuously measures strain and deformation along the cable’s length. It enables the assessment of cable structural health data, ensuring that cables are not subjected to excessive mechanical stress (bending, stretching, etc).

Nexans has been at the forefront of distributed fiber optic sensing measurement technology for high-voltage (HV) cables since the early 1990s, beginning with the installation of a Distributed Temperature Monitoring (DTS) system used for the Skagerrak 3 link between Norway and Denmark. Since then, these technologies have undergone continuous enhancements in length, precision, efficiency, and cost-effectiveness.

With the emergence of innovative new technologies, sensors play a vital role in shifting to smart electrical grids. Sensors provide invaluable data critical to the reliability, efficiency, and adaptability of tomorrow’s grid data management.