Production cost of SF6 is far higher compared to other gases, and its production entails a multi-stage reaction of sulfur and fluorine gas at 300-400 ° C with a production cost of 24,000−28,000 per ton, which is liquid CO
(80/ton) 300 times. In the course of production, 99.999% concentrated fluorine gas is used and energy consumed to purify just the gas accounts for 8.7MWh/ton or 35% of costs. Compared with this, the air-separated produced nitrogen consumes as low as 0.12MWh/ ton and just costs $0.8/ ton. In 2023, global SF6 output is around 10,000 tons, but there are only 8 firms (e.g., Solvay, Kanto Denka), the CR5 of the industry is 89%, and the oligopoly increases the rigidity of the price.
Regulation of the environment has enormously imposed costs of use, and the EU F-gas regulation has compelled SF6 operators to pay a carbon tax of €45/ton CO2e, or €1,057 per kg SF6 based on a GWP of 23,500. California’s bill AB32 makes the penalty higher at 50,000 per leak, prompting PG&E grid to spend 18 million in 2023 to develop sealing technology. The Ministry of Ecology and Environment of China demands 97% recovery rate of SF6, mobile recycling equipment purchasing cost of 280,000, operating costs of 38/kg, and CO₂ system only 0.2/kg. These cost of compliance elevates sulfurhexafluoridecost to 68-85/kg, while industrial-grade nitrogen is merely $1.2/kg.
Technical premium is determined by performance specifications, SF6 insulation capability (89kV/cm) is 2.97 times as much as CO₂ (30kV/cm), nitrogen arc extinguishing capacity 7.5 times. In GIS devices of 420kV, SF6 usage can save 63% (from 18m³ to 6.7m³) of switch cabinet volume, saving 4.2 tons/set of copper material consumption. However, material substitution means redesign of equipment: Siemens’ Clean Air solution (N₂/O₂ blend) reduces GWP to 0 but increases the size of the equipment by 28%, at a further cost in civil construction of $120,000/station. This technology lock-in maintains the market value for sulfur hexafluoride cost.
Supply chain features increase price volatility, SF6 transport necessitates a special high-pressure cylinder (pressure 200bar), a one-time filling price of 18/kg, whereas liquid CO
Storage and transport price is just 0.05/kg. In 2022, fluorite (CaF₂) price surged 73%, which led to a hike of 5,200/ ton in fluorine gas feedstock cost. During the Russia-Ukraine conflict, the shutdown of the Ingas plant in Ukraine reduced the SF6 supply in the world by 12,105 /kg. The supply chain of nitrogen, however, is scattered, with more than 2,000 ASU plants worldwide, and the standard deviation of price fluctuation is only ±4.7%, far lower than the ±23.6% for SF6.
Other technology breakthroughs are reshaping the cost profile, and 3M’s Novec 5110 insulating gas, with a GWP of only 1 and a cost of mass production of 32/kg, has been in commercial application in 145kV circuit breakers. ABB’s EcoGIS solution utilizes dry air to cancel out the voltage of the 420kV substation at a cost saved of life cycle by 418,000/unit · year. Such innovation is breaking SF6’s cost advantage, and according to Wood Mackenzie’s calculations, global demand for SF6 will decline 57% in 2030 from 2023 levels.