An electrician foreman for the Western Area Power Administration checks a circuit breaker at the Ault Substation in eastern Colorado. The circuit breaker, containing 85 lbs of SF6, protects equipment in the substation against damage from excessive electrical currents | Courtesy of Western Area Power Administration. |
Experts
are hunting down fugitive carbon emissions from across 20 Energy
Department laboratories, sites and program offices—and they’ve already
prevented the release of more than 600,000 metric tons of CO2 equivalent
since 2009—equal to taking 140,000 cars off the road for a year.
These
experts are from the Energy Department’s Fugitive Emissions Working
Group (FEWG), led by the Office of Health, Safety and Security. They’re
working to increase the Energy Department’s sustainability and
performance by eliminating energy waste and reducing harmful greenhouse
gas emissions.
Fugitive
emissions—which are inadvertently released often through valve leaks or
breaks—contributed approximately 14% of the Energy Department’s Scope 1 and 2 total greenhouse gas emissions
in 2008. The most common fugitive emission at Department sites is
sulfur hexafluoride (SF6), a nontoxic gas used in electric insulation.
In terms of emissions, one pound of SF6 is equivalent to about 11 tons
of CO2.
FEWG
Chair Josh Silverman remembered, “When we began assessing fugitive
emissions within the Department, we were shocked by how much these
potent gases expand the DOE’s carbon footprint.”
Through
FEWG’s work, between 2008 and 2010, the Energy Department decreased
these emissions by 39%, on track to a 50% reduction by 2012. Over this
time period, SF6 emissions were reduced by over 40%.
Beyond
conducting effective maintenance and repair to reduce leaks, FEWG is
deploying technologies to capture and reuse these gases along with
finding better alternatives.
For
example, Argonne National Laboratory is capturing SF6 gas and reusing
it in electron microscopes, accelerators and other high-energy
equipment.
Sulfur
hexafluoride is also used as a tracer gas for evaluating fume hood
performance in laboratories. To minimize releases, Brookhaven National
Laboratory (BNL) is testing high-efficiency, low flow hoods with nitrous
oxide. So far, BNL has achieved a 98% reduction in fugitive emissions
by testing fume hoods without SF6.
By
driving down fugitive emissions, FEWG’s work has contributed to the
Department’s greenhouse gas reduction goal. Recently, the group was
recognized with a Secretary’s Achievement Award, the Department’s
highest non-monetary honor for a group or team effort.
Still,
the work continues. FEWG is now gearing up to reduce emission rates
even further over the next two years. Several laboratories plan to
install new SF6 capture equipment and expand the use of control
technologies.
“We’re
going to continue to drive these emissions down as far as we can,”
noted Silverman. “Controlling fugitive emissions not only minimizes
climate change impacts from Energy Department operations, it’s also the
Department’s lowest-cost approach to meeting its GHG reduction goals.”
