The first phase of an environmental gas replacement project for gas insulated switchgear at the 110-kilovolt Jianle Substation in Yangzhou, Jiangsu province, was completed on Saturday, marking the first of its kind in the region, according to project undertaker State Grid Yangzhou Power Supply Company.

The project involved replacing the original sulfur hexafluoride gas with a mixture of sulfur hexafluoride and nitrogen gas, saving on economic costs while reducing carbon emissions, said the company.

Such a move is expected to reduce sulfur hexafluoride emissions by 4.3 kilograms annually, equivalent to a reduction of 102,770 kilograms of carbon dioxide emissions, it said.

Located in the southeastern part of Yangzhou, the substation's equipment at the 110 kV voltage level used sulfur hexafluoride gas as an insulating medium due to its good insulating and arc extinguishing properties. However, sulfur hexafluoride is a greenhouse gas with a global warming potential 23,900 times that of carbon dioxide and is relatively expensive.

By replacing the original sulfur hexafluoride gas with a mixture of sulfur hexafluoride and nitrogen gas, not only is the cost reduced, but it also holds greater environmental value in terms of sustainability, said State Grid Yangzhou Power Supply Company.