Representative image showing caution written over SF6
Credit: iStock Photo
By Rajesh Kumar Singh
India’s government and the power industry are exploring a possible phase down of what’s considered to be the most potent greenhouse gas, although high costs of alternatives stand in the way of a regulation.
Sulfur hexafluoride gas, or SF6, which is used as an insulator in power transmission equipment, has a warming potential that’s 23,500 times that of carbon dioxide. It’s found in circuit breakers and switchgears, the demand for which is surging due to the government’s push for more electrification.
The stable nature that makes SF6 an excellent insulator also aggravates its impacts on the climate. The gas can linger in the atmosphere for more than 1,000 years and has high heat-trapping properties. Fluorinated gases, including SF6, accounted for just 2.3 per cent of global greenhouse gas emissions in 2019, but their use has increased rapidly over the past three decades, a trend that is now causing global concerns.
“There’s a need to regulate it and a discussion has started,” Ghanshyam Prasad, chair at the government’s Central Electricity Authority said in an interview. “We’ll need to do it at some point, but for that to happen, costs of alternative technologies need to become affordable.”
Substitutes would require changes in the design and building of equipment that could end up inflating the cost by two to three times, according to Reshu Madan, chief executive officer for global products and services at Sterlite Power.
That’s a big red flag for India’s competitive power market, where the government is already concerned with supply constraints increasing the cost of transmission equipment.
Economies of scale can break the impasse, according to Vikram Gandotra, president-elect at Indian Electrical and Electronics Manufacturers’ Association. “Demand needs to be aggregated from utilities,” which in turn will drive down costs, he said.
Meanwhile, new regulations in some parts of the world have thrust manufacturers into action. The EU has passed norms for a staggered phase-out of SF6-containing switchgears starting from 2026, while US states such as California and Massachusetts have also set rules for either ending their use or limiting leakages.
The equipment employing SF6 is designed to be tightly insulated, but leaks can develop throughout its life cycle, from manufacturing and installation to decommissioning, according to the US Environmental Protection Agency. Significant leakages can occur from aging gear, the agency warned, adding that about 67 per cent of all SF6 emissions in the US in 2022 came from power utilities.