Heat conductive concrete

The UK’s accelerating transition to low‑carbon, renewable energy is placing greater demands on underground power networks. As more electricity is transmitted through high‑voltage (HV) and ultra‑high‑voltage (UHV) cables, managing heat effectively has become essential to maintain capacity.

Unlike overhead lines, buried cables dissipate heat less efficiently because the insulation and surrounding ground restrict heat transfer. Without the right bedding and backfill materials, temperatures rise and reduce cable performance.

Our heat‑conductive concrete range is designed to address this challenge by improving how heat moves away from cables. With proven low thermal resistivity, these mixes support higher power capacity, reduce transmission losses and help extend the life of buried electrical assets. 

Heidelberg Materials' heat conductive concrete is available from all our static and mobile production plants to provide energy-saving benefits for your project.

What applications can heat conductive concrete be used for?

Heat conducting concrete is ideal for applications where consistent and high performing infill is required, including:

• Off-shore wind
• On-shore wind
• Solar farms
• Nuclear power plants
• Modular nuclear reactors
• Data centres
• Substations
• Battery storage facilities
• Subsurface power infrastructure

Benefits of heat conducting concrete

Projects that use our heat conducting concrete will experience a range of benefits, such as:

• Improved heat dissipation for HV and UHV cables
• High heat conduction after drying
• Reduction in magnetic field strength for alternating current
• Increased power capacity
• Reduction of conductor cross-section
• Possibility to switch to aluminium conductors
• Mitigation of “hot-spots”

Our heat conductive concrete range

We offer two concrete solutions that provide low thermal resistance: PowerCrete® and CableCem®. 

PowerCrete®

PowerCrete is a robust, high performance heat conducting concrete primarily used as a bedding and infill material for underground HV and UHV cabling.

Advantages of PowerCrete

The special material properties of PowerCrete result in low heat transmission resistance. As a result, heat generated due to energy transmission is dissipated effectively and the conductor temperature is reduced, increasing the power capability of the cable run.

The workability of PowerCrete can be adjusted to meet the demands of different applications. For instance, a free-flowing consistency is ideal for embedding and encapsulating ducts and cables, while being easy to place, finish and compact.

CableCem®

CableCem is a heat conducting grout developed as an infill material for jacket tube systems.

Advantages of CableCem

The grout shares the same main benefits as our heat conducting concrete and also has excellent free-flowing properties. It’s well-suited for infilling the residual annular space between the cable and the jacket tube.

The low thermal resistance of CableCem ensures excellent heat dissipation, reducing capacity loss in the cable line and permanently increasing the power capability of the cable run. We offer the heat conducting grout in a number of options with a range of thermal resistances - please contact us for more details.

Where our heat conducting concrete has been used

Hurst National Grid Sub-Station

This transformative seven-year project to rewire South London through deep underground tunnels used PowerCrete to enhance power delivery and reliability.

Case study: Hurst National Grid Sub-Station