After 20 years of research, Essential Energy has revealed that vegetable oil can be used as an alternative to traditional mineral oil to insulate transformers, reducing environmental impacts and improving safety.
Essential Energy said it led the industry when it started using vegetable oil in transformer insulation in 2004 which provided valuable data to the industry.
The Essential Energy team proving that vegetable oil can keep transformers running smoother than a well-oiled kitchen includes Senior Engineer, Dan Martin, and Engineering Manager, Lindsay McPherson.
“We began using vegetable oil to insulate transformers adjacent to the National Parks in 2005,” Mr McPherson said.
“In 2007, we joined with Monash University and Ausgrid to do research and development on further use of vegetable oil in the business.
“Now, we have 22 transformers up to 132kV, each containing about 10,000L of vegetable oil along the borders of the National Parks, with more at other sites in our network.”
Mr McPherson said vegetable oils have a higher fire point than standard mineral oil, so there is a safety aspect when using them near buildings and sites with an environmental risk.
“We have them installed near a heritage site in Wagga Wagga, with further transformers to be installed near an irrigation canal at Yenda, a switch room in Lismore and next to a service station in West Bathurst.”
Data from two decades of research from annual tests for acidity, oxidisation and moisture exposure has shown that natural esters such as vegetable oil are proving to be a great alternative to mineral oil in applications where fire risk or environmental sensitivity is a concern.
“We’ve been looking for any changes in the chemical measurements, and so far, all the data has remained within our standards, even during power outages and extreme temperatures,” Mr Martin said.
“We expect about 60 years of life for the transformers, so now that they’re entering their 20th year, this data gives us the confidence they will last another 20–30 years at least.”
Essential Energy said Mr McPherson’s and Mr Martin’s interest in the insulative properties of vegetable oil spans a similar timeframe.
Mr McPherson’s career began as an electrical apprentice in 1973, and he has worked with electrical utilities in regional New South Wales ever since.
Mr Martin has more than 25 years of experience in electrical and electronic engineering and completed his PhD at the University of Manchester in 2008, where he researched the suitability of using vegetable oils as substitutes for mineral oil within large power transformers. In 2007, Mr Martin moved to Monash University where he worked with Essential Energy on this project.
Mr Martin says research into the uses of plant-based oils is still growing, and there could be many business cases as the transition to renewable energy continues. This includes the use of plant-based oils, such as soybean or canola oil, which can be used as insulation in other applications.
“Mineral oil still plays a key role in providing a safe and reliable electricity network, but by integrating plant-based oils into the energy mix, we can move towards more sustainable and environmentally friendly energy systems.”
