Data centres have become essential pillars of the digital economy, providing critical infrastructure for storing, processing, and transmitting vast amounts of data. As the demand for data centres across Europe has surged, so has the need for more reliable, efficient, and scalable power infrastructure. This has necessitated significant advancements in the Low Voltage (LV) and Medium Voltage (MV) power cables integral to data centre operations. The evolution of LV and MV power cables has been driven by the increasing power requirements of modern data centres and by regional regulations, environmental concerns, and technological innovations. This paper explores how LV and MV power cables have changed over the years in European data centres, highlighting cable types and regional variations across Europe.

1. Overview of LV and MV Power Cables

Low Voltage (LV) cables, typically rated up to 1,000 volts (1 kV), are used to distribute power within a data centre to critical components such as server racks, lighting, and cooling systems. Medium Voltage (MV) cables, which generally range from 1 kV to 36 kV, are used to transmit electrical power from substations to the distribution systems within data centres. MV cables often serve as the primary backbone for distributing power to different data centre sections in more extensive facilities.

Historically, data centres operated primarily at low voltage, as the scale of facilities was smaller, and power demands were more manageable. However, as data centres have expanded, especially with the rise of hyperscale facilities, the need for higher-capacity power distribution has led to the increased use of MV cables to handle larger power loads more efficiently. This shift from LV-centric to MV-focused power distribution marks a significant change in cable usage in data centres.

2. Early Stages: Standardisation Across Europe

In the early 2000s, most European data centres relied on relatively standardised LV and MV cable systems. Copper-core cables with polyvinyl chloride (PVC) insulation were the most commonly used, providing adequate performance for the smaller data centres of the time. LV cables were predominantly used for internal power distribution, while MV cables handled power transmission from external sources.

In this period, the difference between countries was minimal, as the requirements for data centres were similar across the continent. The main focus was reliability and safety, with basic fire resistance standards and insulation materials. However, as the demands on data centres increased, so did the sophistication and diversity of the cables used, which were influenced by local regulations and environmental concerns.

3. Transition to Energy-Efficient and Higher-Voltage Systems

The exponential growth of cloud computing, artificial intelligence, and big data analytics in the 2010s necessitated a fundamental shift in how data centres were powered. These new workloads demanded significantly more power, and existing LV systems were no longer sufficient to meet these needs. Data centre operators began turning to MV systems for internal power distribution to ensure greater efficiency and capacity.

The shift to MV cables coincided with cable materials and insulation technologies advancements. Cross-linked polyethylene (XLPE) insulation replaced PVC insulation in many MV applications due to its superior heat resistance, durability, and ability to handle higher voltage loads. XLPE-insulated MV cables became the norm in new data centres, offering improved longevity and performance.

At the same time, aluminium-core cables gained popularity as an alternative to copper-core cables, particularly in MV applications. Aluminium is lighter and more cost-effective than copper while still offering good conductivity, making it an attractive option for large-scale facilities.

4. Regional Variations in Cable Usage Across Europe

While the overall trend towards higher voltage systems and energy-efficient materials has been consistent across Europe, regional variations in cable types and usage patterns have emerged due to local regulations, energy infrastructure, and market dynamics.

1. United Kingdom

The UK, home to major financial hubs such as London, strongly prefers copper-core LV cables in data centres, particularly in mission-critical environments like financial services. Copper offers superior conductivity and reliability, essential in high-stakes environments where even brief power outages can have significant economic consequences.

However, the shift towards hyperscale data centres has also seen the UK increasingly adopt MV systems with XLPE-insulated cables for higher voltage transmission. The UK is known for adhering to stringent safety standards, which has driven the use of low-smoke zero-halogen (LSZH) cables, which reduce the release of harmful emissions in case of a fire.

1. Germany

As a leader in energy efficiency and sustainability, Germany has embraced aluminium-core MV cables, especially in hyperscale data centres. The German market’s focus on reducing energy consumption and transmission losses has led to widespread adoption of energy-efficient MV systems.

German data centres also prioritise renewable energy integration, and MV cables are often designed to handle power loads from sources such as wind and solar energy. As a result, Germany has become a pioneer in adopting innovative cabling systems that are both eco-friendly and highly efficient. Fire-resistant cables with advanced insulation materials are also prevalent, adhering to the country’s strict safety and environmental regulations.

1. Netherlands

The Netherlands, particularly the Amsterdam metropolitan area, has become a significant data centre hub due to its excellent connectivity and infrastructure. The country’s data centres are known for using halogen-free flame retardant (HFFR) cables, driven by a focus on sustainability and reducing environmental impact.

The Netherlands also favours hybrid cables that integrate power and fibre optic lines. These cables allow for more efficient installation and reduce the overall footprint of data centre cabling systems. Aluminium-core MV cables with XLPE insulation are commonly used to balance cost, performance, and sustainability.

1. Nordic Countries

The Nordic region (Denmark, Sweden, Norway, and Finland) is an emerging hotspot for data centres due to its abundant access to renewable energy and cool climate, which helps reduce cooling costs. Data centres in the Nordics typically use robust MV cables designed to withstand harsh environmental conditions, including extreme cold and moisture.

XLPE-insulated MV cables are standard in Nordic data centres, offering durability and efficiency in these challenging conditions. Additionally, there is a growing trend towards using “smart” cables with embedded sensors that monitor temperature and load in real time, enhancing reliability and maintenance.

1. France

With its heavy reliance on nuclear energy, France has unique power requirements in its data centres. MV cables in French data centres often feature enhanced shielding to manage the high power loads associated with nuclear energy sources. The country’s stringent safety regulations have led to the widespread use of fire-resistant cables, ensuring operational continuity even in the event of a fire.

French data centres are also increasingly incorporating eco-friendly cable materials, such as recyclable insulation and low-smoke halogen-free (LSHF) sheathing, which align with the country’s environmental policies.

1. Spain

Spain’s data centre market has expanded rapidly, particularly in cities like Madrid and Barcelona. The country’s focus on renewable energy, especially solar power, has influenced the type of cables used in data centres. MV cables with specific insulation designed for integration with photovoltaic (PV) systems are becoming more common, supporting the country’s drive towards sustainable energy solutions.

XLPE-insulated MV cables are standard in Spanish data centres, particularly as they are well-suited to handle the fluctuating power loads associated with renewable energy sources. Aluminium-core cables are also becoming more popular due to their lower cost and weight advantages.

1. Ireland

Ireland has become a significant hub for data centres, driven by its strong connectivity to North America and Europe. Irish data centres are typically large, hyperscale facilities, and aluminium-core MV cables are favoured for their cost-effectiveness and ability to handle large power loads.

Ireland strongly focuses on sustainability, and MV cables in the country are often XLPE-insulated to ensure efficiency and durability, particularly when integrating power from renewable sources such as wind. Additionally, low-smoke halogen-free (LSHF) cables are widely used in Irish data centres, meeting both safety and environmental standards.

5. Regulatory and Sustainability Drivers

The evolution of LV and MV power cables in European data centres has been shaped not only by technological advancements but also by regulatory and sustainability drivers. The European Union’s Energy Efficiency Directive (EED) and Construction Products Regulation (CPR) have been instrumental in encouraging data centre operators to adopt more energy-efficient and fire-safe cables.

The EED, in particular, has incentivised data centres to minimise energy losses and adopt more efficient power distribution systems, leading to the widespread use of MV cables in more extensive facilities. Meanwhile, the CPR has established fire performance requirements for all cables used in buildings, including data centres, prompting operators to adopt flame-retardant and halogen-free cables.

In recent years, the EU’s focus on reducing carbon emissions has led to a growing interest in eco-friendly cable materials, such as recyclable insulation and biodegradable sheathing. Data centres are increasingly seen as key players in Europe’s transition to a low-carbon economy, and sustainable cabling solutions will play a crucial role in achieving this goal.

6. Future Trends and Innovations

As the European data centre market grows, further innovations in LV and MV power cables are expected. Key trends include:

High Voltage Systems: As power demands increase, some data centres are exploring using high-voltage (HV) systems to improve efficiency further and reduce losses. In the coming years, HV cables could become more common in hyperscale data centres.

Smart Cables: Cables with embedded sensors for real-time monitoring of temperature, load, and other factors are becoming increasingly popular, offering enhanced reliability and facilitating predictive maintenance.

Eco-Friendly Materials: The push for sustainability will continue to drive the use of recyclable and biodegradable materials in cable insulation and sheathing, reducing the environmental impact of data centre operations.

As data centres across Europe continue to grow and evolve, so will the power infrastructure supporting them. The shift towards energy-efficient, high-performance LV and MV power cables highlights the importance of reliability, sustainability, and innovation in modern data centre operations. At Cleveland Cable, we remain at the forefront of these advancements, offering a wide range of cutting-edge cable solutions designed to meet today’s data centres' unique needs. 

For more information about CPR compliance in Data Centres, contact our Global Data Centre Manager, Marcus Ridge, at mridge@clevelandcable.com or 07771 940666.

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