**4. Closing Remarks**

High-voltage transmission networks requiring outdoor insulation or GIS play a very important role in our modern societies, and they are becoming even more essential as efforts are underway to decarbonize our energy usage through increasing electrification (for example, in the personal transportation sector) [53]. The articles published testify that research in this field is very active and that the stakes of electrical insulation are multiple.


The papers published in this Special Issue report on the progress made in various application areas. The combination of experimental work, modelling efforts, and analysis of utility installations help to confirm and explain the results obtained. The outcomes will contribute to design more reliable and more durable insulation systems in the future.

**Author Contributions:** Conceptualization, I.F. and S.B.; writing—original draft, I.F. and S.B.; writing— review and editing, I.F. and S.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no funding. **Acknowledgments:** The gues<sup>t</sup> editors would like to thank the authors for submitting their excellent contributions to this Special Issue. Thanks are also extended to the blind reviewers for evaluating the manuscripts and providing helpful suggestions.

**Conflicts of Interest:** The authors declare no conflict of interest.
