Image source does not exist News Release: 2010-02-25 ARB approves measure to limit most powerful greenhouse gas

Release #:10-19

ARB PIO: (916) 322-2990

Stanley Young

ARB approves measure to limit most powerful greenhouse gas

Regulation targets high-voltage switches using sulfur hexafluoride

Sacramento - Today the Air Resources Board adopted a measure developed with representatives of the electrical utilities that will limit and monitor the emissions of sulfur hexafluoride (SF6) from high-voltage electrical applications.

SF6 is approximately 23,900 times as potent as carbon dioxide in trapping heat in the atmosphere: one pound of SF6 emissions is equivalent to 11 tons of carbon dioxide. The regulation is designed to achieve a 70 percent reduction of SF6 emissions in electrical utility applications with a total reduction of the equivalent of 250,000 metric tons of carbon dioxide in 2020.

“Although it is only used in small amounts, sulfur hexafluoride is the most potent of all the gases that cause global warming,” said ARB Chairman Mary D. Nichols. “This is a narrowly focused regulation that will dramatically reduce California’s emissions of this industrial chemical, at a very reasonable cost.”

SF6 is a highly inert and non-corrosive gas used to insulate switches for high-voltage current applications, typically found in the transmission grid of electrical utilities. These applications constitute eighty percent of the state’s total SF6 emissions. Effective January 1, 2011, the rule sets an initial emission rate at 10 percent of owners’ SF6 capacity. Beginning in 2012 owners of switches using SF6 must reduce emissions by one percent each year, reaching an emission rate of only one percent by 2020.

There are several emission reduction techniques currently available, including: