Regarding gas replacement technology, use of SF6-N2 gas mixture is able to reduce the use of pure SF6 by 40%, while keeping the same insulation level (more than 30kV/cm breakdown field strength). ABB’s ELK-04 GIS station tested how the solution of gas mix reduced yearly purchasing expenditure by $58,000/station and GWP from 23,500 to 9,400. The following quantitative data of the nitrile fluoride (C5F10O) alternative gas manufactured by 3M for use in the 145kV circuit breaker reveal that the greenhouse effect is reduced by 98%, equipment overhaul cost amortization period decreases from 7 years to 3.8 years, and the IRR is driven to 19.7%.
Infrared imaging detection technology raised the efficiency of leak identification by 83%, and leakage rate was lowered from 0.5% to 0.1% per year through magnetic fluid sealing technology. According to Siemens’ report in 2023, its new GIS device utilizes the laser welding technology to control leakage of sealing surfaces to below 0.02cc/hr, down by 92% over traditional designs. Following the installment of a leak management system on a provincial power network, its annual SF6 replenishment declined from 1200kg to 280kg, saving it 84,000 procurement fees and 156,000 carbon allowances.
It comes to gas recovery technology, the recovery ratio of low-temperature rectification unit can up to 98.5% and the purity can be recuperated to 99.99%. Schneider Electric’s SF6 circulation system can extend the lifespan of the gas from 10 to 25 years, and the cost of single treatment $0.8/kg is only 6% of the price of purchasing new gas. Jiangsu province substation employed a mobile recycling car to recycle SF6 650kg yearly, reducing the purchase of new gas by 73%, and the investment payback period is only 1.7 years.
The optimization of equipment upgrade strategy has achieved great results, and the SF6 filling capacity of the 550kV GIS instrument has been reduced from 1200kg to 680kg through modular design. According to the data of the State Grid Wuhan High Voltage Research Institute, the intelligent density monitoring system optimizes the inflation threshold, and the annual gas replenishment frequency is reduced from 4.2 times to 1.3 times. Vacuum circuit breakers replace SF6 circuit breakers in the 40.5kV rating, reducing life cycle costs by 37% and reducing maintenance costs by $12,000/unit · year.
In the area of digitalization, predictive maintenance technologies centered on the Internet of Things reduce equipment failure by 15 percent and provide 28 days’ notice of leakage risk in advance by vibration monitoring and partial discharge monitoring. European grid operator TenneT implemented a digital twin system, resulting in 40% increase in preventive maintenance efficiency and 63% reduction in unplanned downtime. Ai-based inventory management system reduces security inventory from 3 months to 23 days, reducing capital occupancy by $580,000/year.
Policy incentives to create new value, the EU ETS carbon price quota of €96/ton CO2e, companies can reduce SF6 use by 1 ton of €21,500 carbon credits. California’s AB32 legislation mandates utilities to cut SF6 use by 50 percent by 2025 from the 2019 level, leading PG&E to spend 47million dollars on retrofitting equipment, which will save 18 million dollars annually in operating expenses from 2026. In China’s green electricity trading pilot program, environmentally friendly alternative gas substations earned 0.015/kWh premium, with a 2.7 million annual increase.
Supply chain optimization and significant sulfur hexafluoride cost reductions, price volatility secured through long-term purchase contracts, a provincial energy utility through a 5-year contract SF6 purchasing unit price fixed at 68/kg, 239.2/kg below from the spot market. The warehousing and logistics system centralized reduced transport losses from 0.7% to 0.1%, reducing gas losses by $43,000 per year.