CEA Committee Report Outlines Phased Rollout of SF₆-Free Green GIS in India’s Transmission Sector

The Central Electricity Authority (CEA) has released a detailed committee report outlining a structured roadmap on the use of Green GIS (Gas Insulated Substation) Technology in Indian Grid.

The initiative aims to significantly reduce dependence on sulfur hexafluoride (SF₆), a potent greenhouse gas widely used in conventional GIS equipment.

The report highlights that SF₆ has an extremely high global warming potential, over 24,000 times that of carbon dioxide, making it a major environmental concern in the electricity transmission ecosystem. In response, the committee has recommended a gradual shift toward SF₆-free alternatives such as fluoronitrile-based gas mixtures and clean air systems combined with vacuum interruption technology.

According to the roadmap, Green GIS technologies are already considered technically viable at lower voltage levels such as 132 kV, but require further validation for higher voltage applications like 220 kV and above. The committee has therefore proposed pilot projects in India under real operating conditions before wider deployment.

The transition strategy suggests initiating pilot installations in 2027–28, followed by a phased expansion. By 2029–30, around 10 percent of new GIS installations are expected to adopt SF₆-free technologies, with gradual scaling in subsequent years depending on performance outcomes and cost reductions.

However, the report also notes significant challenges. Green GIS systems currently cost nearly six to eight times more than conventional SF₆-based equipment and rely heavily on imported components and gases. Project execution timelines are also longer due to supply chain constraints and limited domestic manufacturing capacity.

To address these issues, the committee has emphasized strengthening India’s local production ecosystem, including development of fluoronitrile manufacturing, upgrading existing GIS production facilities, and building testing infrastructure. It also recommends improved workforce training, standardized gas handling practices, and mandatory environmental evaluation criteria in procurement processes.

The report further suggests regulatory measures such as SF₆ usage tracking, reporting requirements, and gradual restrictions on procurement to support the transition.

Overall, the CEA envisions Green GIS adoption as a key step toward decarbonising India’s transmission infrastructure while maintaining grid reliability and supporting long-term climate goals.