While you use a low-voltage circuit breaker to switch power on and off in your domestic network, electrical utilities use high-voltage circuit breakers. Circuit breakers run along the electrical grid to power cities from high-voltage substations. However, when space is a constraint, the circuit breaker is compacted in a gas-insulated substation (GIS) together with the other electrical devices. For more than half a century, SF6 gas has been used in high-voltage substations as an insulating medium and to cut the current and redirect the power flow more effectively. The drawback is that SF6 has a very high global warming potential and remains in the atmosphere for roughly 1,000 years.

That’s why our project aims to develop a solution to replace SF6 with a gaseous mixture in a large part of the installed GIS. The objective is to propose a technically and economically viable solution without the need to replace the entire substation. With this unique retrofit solution, we will not only allow utilities to reduce the carbon impact of their installed GIS base, but we will also help them extend the lifespan of their equipment and avoid the need to buy a fully new substation.