Electricity + Control November 2017

Natural Ester Fluids: New Tool for Operational Gains

Information provided by Cargill Industrial Specialties (Cargill)

Changing marketplace forces have power companies looking to natural es- ter fluids as a transformer coolant and insulating fluid that can help them capture cost efficiencies and improve performance.

W hen natural ester fluids first came on the market as a coolant and insulating fluid for transformers in 1998, they were seen primarily as a ‘green’ alternative to mineral oil. Be- cause they are typically more expensive than mineral oil, their usage was limited primarily to installations where environmental or fire safety was at a premi- um. A recent trend, has emerged, however, that shows utility companies are increasingly turning to natural ester fluids to help them capture the oper- ating efficiencies they need to remain competitive. In 2013, CPFL Energia, the largest privately owned energy company in Brazil, announced that it would begin changing all of its transformers to a natural ester fluid coolant and insulator. CPFL’s distribution network serves roughly seven million customers in 569 towns and cities in southern Bra- zil. Also in 2013, the largest natural ester fluid-filled power transformer in the world was brought on line whenTransnet BW commissioned a 420 kV substa- tion transformer filled with natural ester fluid at its Burchsal-Kändelweg substation. After three years in service undergoing multiple monitoring tests, the transformer is operating perfectly and within the IEEE operational guidelines. And most recently, Tata Power − India’s largest integrated power com- pany serving Mumbai, has selected natural esters for their distribution and power transformers. Like Transnet BW and CPFL Energia, Tata Power select- ed Cargill’s Envirotemp FR3 fluid (the most widely used natural ester fluid) for its transformers. These companies are just a few of the many that are finding that natural ester fluids are no longer a niche product, but rather a new tool that can help them capture real value in an ev- er-changing marketplace. To date, more than 100 U.S. utilities − including a major power company in northern California that maintains roughly a mil- lion transformers in its distribution system − have

made substantial investments in transformers filled with natural ester fluids. And dozens more are considering following in their footsteps. In part, they are doing so simply because they now better understand the advantages natural ester flu- ids offer compared to mineral oil. Natural Ester Fluids gain understanding, verification During the past two decades, natural ester fluids have demonstrated their performance more than off sets the added cost relative to mineral oil. When it comes to the environment, natural ester fluids are superior to mineral oil. According to Environmental Protection Agency guidelines, natural ester fluids are deemed to be ‘readily biodegradable’ (meaning they will completely biodegrade in 28 days). They have been classified as non-toxic and non-hazard- ous in soil and water by the Organisation for Eco- nomic Cooperation and Development. The carbon footprint for natural ester fluids − which have been determined to be carbon neutral through a BEES 4.0 lifecycle analysis − results in 56 times less car- bon emissions than mineral oil. Additionally, there are now industry standards in place to help utilities adopt and integrate natural ester fluids in the pow- er industry; ASTM, IEEE, and IEC, for example, all have published standards for natural ester fluids. More importantly, in the eyes of power com- pany business managers, natural ester fluids’ oth- er characteristics are being proven more valuable than even their environmental benefits. Consider the following natural ester fluid facts: • Their flash point and fire point are more than twice that of mineral oil and are classified as less flammable fluids by Underwriters Labora- tory (UL) and FM Global Approved. As a result, natural ester-fluid filled transformers can be placed closer to one another and to buildings,

Take Note!

Natural ester fluids have demonstrated that their performance more than off-sets the added cost relative to mineral oil. When it comes to the environment, natural es- ter fluids are superior to mineral oil. Natural ester fluids are deemed to be ‘readily biodegradable’ (mean- ing they will completely biodegrade in 28 days).

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26 Electricity + Control

NOVEMBER 2017