As electricity networks expand to support the energy transition, attention is increasingly turning to the materials that make transformers possible. Performance and reliability remain essential, but manufacturers are now expected to deliver solutions that also reduce environmental impact, simplify production and support recycling at the end of an asset's life. 

This is prompting a fresh look at materials that have changed little for decades. 

Thermoplastics are emerging as a promising alternative to conventional insulation materials, offering manufacturers new opportunities to improve productivity while supporting more circular approaches to transformer design. Rather than treating sustainability as an end-of-life consideration, these materials demonstrate how environmental performance can be built into every stage of the value chain.  

Material selection is becoming a strategic decision 

The demands placed on transformer materials continue to increase. 

Manufacturers require insulation systems capable of operating reliably under demanding electrical, thermal and mechanical conditions, while utilities expect assets to deliver longer service lives with minimal maintenance. Increasingly, both groups are also evaluating the environmental impact associated with material choices. 

Thermoplastics are attracting attention because they offer comparable, and in some cases enhanced, performance while introducing additional benefits such as recyclability, lower processing energy and greater manufacturing flexibility. 

This combination allows manufacturers to evaluate materials not only on technical performance but also on their contribution to productivity and sustainability.  

Better manufacturing starts with better materials 

The impact of material innovation extends well beyond the finished transformer. 

Thermoplastics simplify production through easier extrusion processes while reducing energy consumption during manufacturing. They also eliminate several time intensive processing stages associated with traditional insulation materials, helping manufacturers reduce production downtime and improve throughput. 

These efficiencies become increasingly valuable as transformer demand continues to grow and manufacturers seek ways to increase capacity without compromising quality. 

At the same time, the materials maintain the electrical insulation, thermal stability and mechanical durability required for demanding grid applications, demonstrating that improved manufacturing efficiency does not need to come at the expense of technical performance.  

Designing for a longer service life 

Material performance also influences how transformers operate over decades of service. 

Moisture remains one of the main causes of insulation degradation, affecting long term reliability and ultimately limiting transformer life. Thermoplastics offer greater resistance to moisture absorption while remaining compatible with a range of transformer oils, helping preserve insulation quality throughout the asset lifecycle. 

By reducing degradation and supporting more stable operating conditions, these materials have the potential to extend service life while lowering maintenance requirements and operational costs for asset owners.  

Circular thinking begins at the design stage 

Perhaps the greatest opportunity lies beyond manufacturing. 

As circular economy principles become more important across electrical manufacturing, transformer designers are increasingly considering how products will be recovered and recycled after decades of operation. Thermoplastics support this approach by enabling cleaner separation from copper during recycling and offering inherent recyclability that traditional materials cannot always provide. 

Combined with renewable energy, sustainable feedstocks and post industrial recycling within material production, this creates a more complete approach to reducing environmental impact across the entire product lifecycle rather than focusing solely on operational efficiency.  

Material innovation is becoming an increasingly important part of building a more sustainable power sector. At CWIEME Berlin, transformer manufacturers, material specialists and engineers come together to explore how advances in insulation systems, manufacturing technologies and circular design are reshaping electrical manufacturing. As sustainability expectations continue to evolve, collaboration across the value chain will be essential to delivering transformers that perform throughout their entire lifecycle.