Uppsala University studied alternative high voltage oils for modulators in the framework of the AWAKE collaboration.
Mineral oil manufactured from fossil fuels is the most widespread type of oil used for electrical insulation in transformers. Although a very capable insulator, its source materials and poor biodegradability mean that finding more environmentally friendly alternatives, such as vegetable oils, is highly desirable. In this study, a number of popular high-quality mineral oils were compared to a selection of ester-based oils by means of breakdown voltage and complex permittivity measurements. The results show that some of these greener alternatives can potentially replace mineral oil in transformer applications without compromising on electrical performance.