Green Transition: Standards for transformers and insulating oil

As part of the shift towards a sustainable energy supply, transformers play a crucial role in the green transition. Serving a critical function in electricity distribution networks, they ensure the efficient transmission of energy. However, their performance relies heavily on insulating oils, which must meet stringent environmental and safety standards. This article explores the standards governing transformers and insulating oils within the framework of an environmentally friendly transition.

Yes, there are norms and standards for transformers and insulating oils, but... 

1. Did you know that the introduction of stricter legal regulations often does not keep pace with developments in transformer oil practice?
The growing demand for environmentally friendly solutions in the energy sector is bringing the topic of recycling more into focus. The introduction of stricter legal regulations and international standards is, on the one hand, motivating manufacturers to use more recycled materials. On the other hand, greater education and support from governments and industry leaders is needed to accelerate this process.

2. Did you know that there are established structures alongside the agreed standards?
Standards for transformers and insulating oils play a vital role in ensuring safety, efficiency, and sustainability. However, they are just one piece of the puzzle. In the UK, practical experience suggests that data sheets and specifications of recycled insulating oil products often hold great significance, highlighting the importance of real-world application and product-specific requirements.

3. Did you know that recycled insulating oils fulfil the same standards as new products?
In fact, the IEC 60296 standard also covers the recycling of transformer oils and ensures that the same performance requirements are met.   

Standards for transformers

Transformers are subject to a number of international standards that set standards for safety, performance and environmental compatibility. These standards ensure that transformers operate efficiently while minimising their impact on the environment.  

• IEC 60076 series: This series from the International Electrotechnical Commission (IEC) contains comprehensive guidelines on aspects such as rated power, efficiency and short-circuit behaviour.
• Energy efficiency requirements: Regulations such as the EU Ecodesign Directive require efficiency improvements and promote the use of energy-efficient transformers that reduce power losses.  
• Safety and environmental standards: These include standards for noise emissions, electromagnetic compatibility and recycling, which ensure that transformers operate safely and sustainably throughout their life cycle.  

Standards for insulating oils 

Insulating oils are essential to the operation of transformers, serving both as cooling agents and as electrical insulators. Their quality and handling are regulated by various standards to ensure environmental compliance and equipment safety. 

• Quality control and testing: Strict testing to standards such as ASTM D 3487 and IEC 60296 evaluates the purity and dielectric strength of supplied insulating oils.  
• Biodegradability standards: With the shift towards increasing environmental awareness, biodegradable esters are becoming preferred alternatives to traditional mineral oils in certain specific scenarios and applications.  
• Toxicity and environmental impact assessments: Standards such as the OECD Guidelines provide a framework for assessing the environmental impact of insulating fluids, guiding manufacturers towards more environmentally friendly options. 

Innovations and alternatives to mineral transformer oils

The green transition requires constant innovation that leads to the development of alternatives that meet environmental requirements. This includes the use of synthetic and natural esters, which have a lesser impact on the environment if spilled:

• Natural esters:
  They are derived from vegetable sources, are non-toxic, biodegradable and have a high flash point, making them a sustainable alternative to mineral oils. They are often referred to as vegetable oils or bio-oils and are produced from renewable sources such as rapeseed, soya or sunflowers.  
  • Advantages: Environmentally friendly (biodegradable), high flash points, non-toxic.
  • Disadvantages: Higher viscosity (can affect cooling), more expensive and currently harder to recycle than mineral insulating oil. 
• Synthetic esters: Synthetic esters are increasingly being used as a replacement for mineral oil, especially in areas where there are increased environmental or fire safety requirements.
  • Advantages: Biodegradable, higher flash point, less harmful to the environment.  
  • Disadvantages: More difficult to recycle and more expensive than mineral oil, but preferable in certain applications due to its advantages. 

Focus remains on the beneficial recycling of mineral oils

Ongoing research focuses on enhancing the performance properties of insulating oils to achieve greater thermal stability and longer service life.  

However, the best opportunity for transformer asset owners to help drive businesses towards a sustainable future is the efficient recycling of mineral oils when they no longer achieve the high performance requirements necessary for its application. These in service insulating oils are regenerated using innovative methods to restore their purity and functionality for reuse. This circular economy contributes significantly in reducing the environmental footprint of the transformer industry.

Read more about recycled mineral transformer oils here:

• Yellow is the new white: EOS^® Premium recycled insulating oil is this pure   

Conclusion: Standards for transformers & their oil ensure safety

Standards for transformers and insulating oils are essential on the path to sustainability. They ensure the safety and efficiency of power supply systems while supporting environmental responsibility and resource conservation. As new technologies evolve, continuous updates and adherence to emerging standards are vital to enable a smooth transition to eco-friendly systems and foster a resilient, sustainable energy future.

Read more:

• EOS^® Interview: 5 tips for sustainable transformer oil management
• Insulating oil recycler, lab expert, general contractor: Meet EOS^®!
• Case study insulating oil: Extending service life of transformers

Do you have any questions about this blog article or other topics relating to transformer oils? We look forward to hearing from you.