Total cost of ownership solutions for transformers.

We often get asked, “So, how much does natural ester oil cost compared to mineral oil?” Even though the comparative fluid price of natural esters is higher than mineral oil, natural ester oil could save you money in a number of ways.


Fluid-to-fluid comparison: mineral oil and natural ester oil

If you just compare the cost of mineral oil to natural ester oil, it will most likely be higher. There are many customers who find the additional cost well worth the enhanced fire safety (2x flash and fire point as mineral oil, highest fire point of any dielectric fluid) and environmental benefits (biodegradable, non-toxic and non-hazardous in water and soil, carbon neutral* and simpler spill remediation). We find organisations in environmentally-sensitive areas such as parks and waterways deem these features essential. These increased fire safety and environmental benefits far outweigh the increased fluid cost.

*According to BEES 4.0 Lifecycle Analysis



Optimised transformers

Taking advantage of natural ester fluid’s interaction with cellulose insulation enables transformers filled with natural ester to be designed to operate up to 20°C warmer than the mineral oil-filled alternative. The value to utilities includes increased load capability (up to 20% more), extended insulation system and asset life (5-8x more than mineral oil), and lower maintenance costs.

By optimising transformer designs with natural ester oil to either 75AWR or 85AWR, organizations have the flexibility to:

  • Buy smaller transformers yet maintain the same load capacity, which helps reduce initial costs
  • Redesign transformers for a smaller footprint to not only save on initial cost but help address space constraints (e.g. densely populated urban areas, amusement parks, malls)
  • Extend the asset life of the transformer which can significantly reduce the total life cycle cost of the asset

With an optimised transformer design, the cost for a natural ester oil-filled transformer is typically within +/- 5% of the cost of a mineral oil transformer. We believe the additional operational efficiencies gained by optimising transformer performance (in addition to the fire safety and environmental benefits) offers significant total value to the organization.


Total transformer system yields broader operational efficiencies

Beyond the individual transformer performance, there are broader organizational operational efficiencies to be gained when transformers are viewed from a total cost of ownership perspective. Additional cost savings could include:

  • With natural ester fluid’s high temperature capability, new transformers can be designed smaller using up to 15% less fluid and up to 3% less construction materials (copper, steel and/or aluminum, insulation material, etc.), supporting the sustainable supply chain initiatives.
  • Eliminate costly fire mitigation, deluge systems and fire walls as natural ester fluid is an FM Approved, UL classified less flammable fluid. Furthermore, these transformers can be placed closer to buildings saving precious real estate.
  • Simplify spill containment systems such as earthen berms versus expensive cement systems. Also, spill clean-up can be less intrusive with bio-remediation given natural ester oil is ultimately biodegradable.
  • Reduce transformer inventory by using the base load through the upper load capacity of natural ester fluid-filled transformers on dual-rated designs (e.g. a single 65/85AWR design may enable application at 100 through 125 kVA applications). This unit flexibility may enable design consolidation and improved inventory management.

How can natural ester oil benefit your organisation?

There are many nuances to evaluating total cost of ownership and each organization is different. We believe there are a number of ways natural ester oils can impact your transformer performance and bottom line.

What value could natural ester fluid offer your organisation? Contact our team to help you incorporate these cost-saving, performance-enhancing solutions into your grid.