Introduction and field experience with SF6-free equipment in the transmission grid of TransnetBW

This paper reports on TransnetBW actions regarding the research, planning, installation, and on-site testing of different SF6 alternative gases aiming to gain own experience, reduce the SF6 emissions, and to speed up its replacement in the high voltage equipment. The Transmission System Operator recognized very early the importance of SF6 phase out and started looking into the on-site testing of alternatives already in 2016, well before agreements such as Green Deal, Fitfor55 or laws such as German Law of climate protection were announced. The climate neutral gas mixtures with a GWP < 1 have been preferred from the beginning. At the next steps partnerships were establish with different transmission and distribution equipment manufacturers, who were willing to develop climate neutral SF6-alternatives. The projects and the products selected for the on-site testing of the SF6-alternatives are presented in the paper. The experience gained so far and the strategy to replace the SF6 are also presented in the paper.