Since it invention, the transformer has evolved in terms of added functionality and size to keep pace with rapidly changing and complex electric power systems. One thing that has remained virtually unchanged since it was first
applied in Germany in 1890 is the use of mineral oil as an insulating and cooling media. However, the global crude oil crisis in the early 1970s and the ever increasing demand for environmentally friendly combustibles has seen the birth of several
initiatives as well as extensive technology developments focused on finding alternative fuels, in particular for the automotive industry.