MV cables powering the energy transition
By Mark Froggatt, Head of Technical Training, Learning & Development
Much of the progress being made in modern power systems relies on infrastructure that rarely draws attention to itself. Beneath renewable generation projects, industrial sites, and transport networks lies a layer of electrical distribution that plays a decisive role in how efficiently, safely and reliably energy is delivered. Medium Voltage cables sit firmly within this layer, providing the foundation on which today’s evolving power landscape is being built.
Medium Voltage cables, typically framed as operating from above 1kV up to 35kV, bridge the gap between high voltage transmission networks and low voltage distribution to end users. They are designed to carry significant electrical loads while maintaining reliability, safety, and long service life. In practical terms, they form the backbone of modern power distribution, supporting critical infrastructure, industrial operations, and renewable energy integration.
Over more than 20 years in the cable industry, I have seen expectations placed on medium voltage networks increase significantly. Power systems may still operate on time honoured electrical principles, but the way electricity is generated, distributed, and consumed has changed considerably. Demand is rising, loads are becoming more concentrated, and generation is increasingly dispersed across the network. Medium Voltage cables sit at the centre of all of this.
Moving more power, more efficiently
The core function of medium voltage distribution has always been efficiency. Transmitting power at increased voltages allows greater quantities of electricity to be moved at manageable conductor sizes with lower losses and without the impractically large conductors that low voltage systems would require. As power demand continues to grow, particularly in industrial and commercial environments, this efficiency has become essential.
Industrial facilities illustrate this well. Manufacturing and processing facilities are becoming more automated and increasingly dependent on electrically driven systems, resulting in higher and more sustained power demand. Supplying these loads via medium voltage distribution allows power to be moved efficiently across a site, with currents kept at manageable levels and LV infrastructure concentrated closer to point‑of‑use. This approach helps control losses, physical congestion, and overall system complexity. Similar challenges exist in logistics hubs and large commercial developments, where power demand is both substantial and continuous, and must be distributed reliably across large footprints.
Digital infrastructure adds another dimension. Data centres are under constant pressure to deliver greater computing capacity within tightly constrained physical footprints, energy availability, and cooling limits. Medium voltage distribution is typically used to transfer large amounts of power efficiently from grid connection points or on‑site substations to local distribution nodes within the facility, with low‑voltage systems serving equipment at the rack or room level. This architecture supports high power densities while helping to manage losses, space requirements, and future capacity expansion. In such environments, cable performance is a fundamental contributor to long‑term reliability rather than a secondary consideration.
Renewables and a more dynamic grid
The growth of renewable energy has reshaped the demands placed on medium voltage networks. Power generated by wind farms, solar photovoltaic installations, and battery storage systems is stepped up from low voltage to medium voltage for collection and export to substations or wider distribution networks.
Unlike conventional generation, renewable output is inherently stochastic, leading to changing load profiles and increasingly bidirectional power flows across electricity networks. While these effects are addressed at network level, they place specific demands on medium voltage cable infrastructure. Appropriate cable design, material selection, and installation practices are essential to ensure reliable performance under fluctuating operating conditions and diverse installation environments.
Electrification and higher power density
Electrification is accelerating across multiple sectors of the economy. Transport infrastructure, including rail networks, ports, and commercial vehicle depots, is becoming increasingly dependent on electrical power as a primary energy source. These facilities commonly combine high connection capacities with constrained physical space, placing growing demands on the underlying network infrastructure.
Electric vehicle charging installations provide a clear illustration of this trend. While individual charge points are supplied at low voltage, large fleet depots and transport hubs can present substantial aggregated power demand. As sites expand or charging capacity increases over time, this demand is typically supported through medium voltage connections feeding local substations and LV distribution systems.
As a result, electrified transport infrastructure places particular emphasis on the performance of the medium voltage networks that support it. Decisions made at the network interface, including capacity planning, equipment layout, and allowance for future growth, play a key role in how effectively these sites operate over time.
Taking the long view on specification
Medium Voltage cables are long-term assets. Once installed, they are expected to perform reliably for decades, often with limited access and minimal intervention. That makes the specification stage critical.
Standards provide an essential framework, but they do not remove the need for judgement. Two cables may meet the same standard yet behave very differently depending on materials, construction, and suitability for a specific environment. Understanding how cables perform in real-world applications, across different sectors and conditions, is often the difference between a resilient system and one that creates ongoing operational challenges.
Over time, there has been a noticeable shift in how cable selection is approached. Designers, engineers, and asset owners are paying closer attention to how medium voltage cable networks underpin the reliability and future-proofing of entire power grids.
Built into the future of energy
Medium Voltage cables may not attract the same attention as generation technologies or high-profile infrastructure projects, but their role in the energy transition is fundamental. As power systems become more complex, with greater demands from renewables, electrified transport, industry, and digital infrastructure, the importance of robust, well-specified MV cables continues to grow.
Their work is largely unseen, but the impact is felt everywhere. Ensuring that medium voltage networks are designed with care, experience, and long-term performance in mind is essential to delivering power systems that are efficient and ready for what comes next.
