California will regulate the emissions of sulfur hexafluoride (SF6) from electric utility equipment starting in 2011, reports the New York Times. SF6 is used to insulate switches typically found in high-voltage transmission systems, which accounts for about 80 percent of California's total SF6 emissions.
"Although it is only used in small amounts, sulfur hexafluoride is the most potent of all the gases that cause global warming," said Mary D. Nichols, California Air Resources Board's (CARB) chairwoman, in a statement.
Starting on Jan. 1, 2010, the CARB measure sets an initial emission rate at 10 percent of the utility's SF6 capacity, which will be followed by reductions of one percent each year from 2012 to 2020. CARB targets a 70 percent reduction of SF6 emissions, which is equivalent to about 250,000 metric tons of carbon dioxide in 2020.
CARB says there are several emission reduction techniques that utilities can implement now to reduce SF6 emissions, including leak detection and repair using handheld sniffer devices and cameras, and refurbishing or replacing existing equipment. The total cost to utilities over the ten-year period will be about $4.5 million to $7.5 million, which will be passed on to utility consumers at a rate of one cent per month.
A spokesman for the board, Stanley Young, told the New York Times that California is the first state to set mandatory reductions in SF6 emissions for utilities.
In 2007, CARB approved measures to reduce SF6 emissions from the non-electricity sector including manufacturing processes with aluminum, magnesium and semiconductors, as well as a tracer for air quality and vehicle studies, which went into effect on Jan. 1, 2010.
Emissions reductions in the U.S. utility sector have been voluntary through the U.S. Environmental Protection Agency's SF6 Voluntary Partnership for Electric Power Systems program, reports the New York Times. Eighty-one utilities participate in the program, accounting for 47 percent of the nation's high-voltage transmission systems.
