Comment Log Display

I would like to offer the following information in support of the
CARB's proposal for tighter limits on Sulfur Hexafluoride (SF6) gas
emissions from electrical equipment:
 
SF6 gas was initially introduced to the electrical industry for
its arc quenching and insulation properties in high-voltage circuit
breakers.  It then evolved as a replacement for oil in lower
voltage circuit breakers above 15,000-Volt (15-kV).  At 15-kV and
below, air replaced oil as an interruption and insulation medium. 
The next technical development in the late 70’s was the advancement
of vacuum interruption technology up to 38,000-Volt (38-kV), with
air as the insulating medium.  
 
Unfortunately, SF6 gas has found its way into electrical products
such as switches, contactors, disconnects, transmission lines,
transformers, circuit breakers, substations, and in underground
vaults as low as 2400-Volt (2.4-kV).  
 
Many of these products come into the US from other countries.  The
CARB should take comfort in the knowledge that today, electrical
products at or below 72,000-Volt (<72-kV) that do not contain SF6
are commonly available at competitive prices from many electrical
equipment manufacturers. Furthermore, the marketplace now has a
retrofit product for removing SF6 and replacing it with vegetable
oil as an insulator.

Therefore, in the document dated January 7, 2010, “Initial
Statement of Reasons”, the sentence found in the “Executive
Summary”, B - Overview, paragraph 7, page 8 of 39: “Despite
international research efforts, no equivalent alternative has been
identified”; and SECTION – I, Introduction, C – Background,
paragraph 4, page 13 of 39: “Despite international research
efforts, no equivalent alternative has been identified” are not
completely true statements.
 
In addition to the significant GHG impact, SF6 has another
negative attribute. Although non toxic in its natural state, arced
SF6 is highly toxic, especially in indoor environments.  This
condition will result in the event of an electrical failure of the
device, thus relegating the remediation to a hazardous materials
disposal.
 
The above should be considered as factors in support of even
tighter restrictions on replacement and new installation of
electrical equipment containing SF6. CARB should reconsider the
position as stated in the document dated January 7, 2010, “Initial
Statement of Reasons”, SECTION – III, Proposed Regulation
Development, C – 3, paragraph 1, page 21 of 39: “Staff evaluated
the option of establishing performance standards and mandating the
replacement on medium voltage (<69) kilovolt (kV) switchgear. Staff
also evaluated requiring establishing standards for new equipment.
However, by choosing instead to set a less-prescriptive, maximum
allowable emissions rate to meet the GHG emission reduction goal,
affected entities would be motivated to purchase the lowest
emitting GIS equipment.”

 It is important the CARB address issues regarding the replacement
of any existing equipment <72-kV that has reached its maximum
operating life, as well as ban the use of SF6 in new equipment
installed in commercial and industrial applications at lesser
voltages, thus, eliminating the future source of possible emissions
versus just reducing the potential for dangerous emissions in
existing installations. Viable and extensively available
alternatives up to 72-kV exist throughout the industry.
 
Furthermore, in the document dated January 7, 2010, “Initial
Statement of Reasons”, SECTION – I, Introduction, C – Background,
paragraph 3, page 12 of 39: “The advantages of using SF6 in
electrical switchgear are considerable, primarily because the gas
is non-flammable, non-corrosive to internal switchgear components,
and its thermal properties make it an excellent arc suppressant.”

The above reasons are no longer valid for electrical equipment
<72-kV, where viable and extensively available alternatives exist
throughout the industry.

These so-called “considerable advantages” cannot be harmonized
with what is stated in the document dated January 7, 2010, “Initial
Statement of Reasons”, SECTION – V, Environmental Impacts, B,
paragraph 3, page 28 of 39: “While SF6 is inert during normal use,
when electrical discharges occur within SF6-filled equipment, toxic
by products may be produced which pose a health threat to workers
who come into contact with them.”

It is imperative that California continue to be the national – and
world - leader in Public Health and Safety, as stated in the
document dated January 7, 2010, “Initial Statement of Reasons”,
SECTION – II, Statutory Requirements, paragraph 16, page 15 of 39:
“The proposed regulation may serve as a model for future federal
regulations further reducing GHG emissions from the high global
warming potential gas.”