SF6
from Cooper Power Systems
THE ULTIMATE GAS-FREE, OIL-FREE AND
MAINTENANCE-FREE SOLUTION FOR
AUTOMATION, PROTECTION AND SWITCHING
APPLICATIONS
NOVA Technology
Kyle Distribution Switchgear
SF6
Cooper Power Systems
Advances NOVA Technology
to Protect the Environment
SF6 Prompts Many Concerns
Safety
SF6 is heavier than air and does not readily disperse,
thus creating hazards in confined areas. It is odorless
and essentially colorless, and its presence is not easily
detected. The potential of asphyxiation in confined
areas is a hazard which can result in death. Regulations
regarding monitoring, inspection, work rules and procedures add to the overall cost of operating and maintaining equipment. Additional safety equipment may
become necessary in the near future.
New switchgear developments offer alternatives to the
use of oil for purposes of insulation and, at times, current interruption. Two available alternatives to the use
of oil in switchgear are the use of a solid insulation system (NOVA) or SF6 gas.
The evaluation of any alternative involves consideration of many factors, including total cost, safety, and
more important than ever before, environmental concerns. These factors are inter-related, especially as to
how concerns regarding the environmental impact of
SF6 gas affects the total cost of operating and maintaining equipment.
Environment
The most serious concern about the use of SF6 is its
effect on the environment as a greenhouse gas.
Greenhouse gases are atmospheric gases that absorb a
portion of the infrared radiation emitted by the earth
and returns it to earth by emitting it back. Most potent
greenhouse gases have strong infrared absorption and
occur naturally in the environment or are man-made
gases that are released into the environment. Examples
of man-made greenhouse gases include fully-fluorinated compounds (FCC), combustion products (CO2), and
sulfur hexafluoride (SF6). Man-made greenhouse gases
contribute to the shift of balance between outgoing and
incoming radiation in the earth’s atmosphere, causing
global warming. Since SF6 is largely immune to chemical and photolytic degradation, its contribution to global warming is expected to be cumulative and virtually
permanent.
Cooper Power Systems, Kyle Distribution Switchgear
has selected a solid insulation system as the ideal
approach to eliminate serious problems and concerns
regarding the use of SF6 gas.
Electric Power Industry Must Look to
the Future Without SF6
Some users may exhibit complacency regarding the use
of SF6 gas in switchgear products. This complacency is
based on past experience and perhaps a lack of awareness of possible future regulations and restrictions
involving the use of SF6 gas. Decisions to purchase and
propagate equipment utilizing SF6 gas are most likely
made without full recognition of present problems and
concerns with regard to leaks or the escalating cost of
SF6 gas. A more serious consideration is the prospect of
increasing government restrictions and regulations on
the use of SF6 gas, due to its effect on the atmosphere
as an extremely potent greenhouse gas.
Why is SF6 a Serious Environmental Concern?
SF6 has serious effects on the atmosphere. For example,
one ton of SF6 equals 24,900 tons of carbon dioxide in
terms of 100 year Global Warming Potential (GWP).
Compounded, SF6 has an extremely long atmospheric
lifetime (estimated between 800 to 10,000 years). As a
result, SF6 is among the most potent of greenhouse
gases.
The use of SF6 in distribution switchgear products may
suffer the same fate as PCB’s and Freon. Selection of an
insulation medium, therefore, should include an evaluation of the future status of SF6 gas.
2
SF6
Costs
Kyoto Protocol Urges Action Against SF6
The Kyoto Protocol recommends that countries take
action to reduce the emissions of all greenhouse gases
by specified levels. For the United States, the specified
reduction in emissions is to be seven percent below
1990 levels. Because one ton of SF6 is equivalent to
24,900 tons of carbon dioxide as a greenhouse gas, SF6
is a prime target for strict control and limits to its use.
The special handling, equipment, and procedures
required for SF6 increases the total cost of owning and
operating SF6 gear well beyond the initial purchase
price.
The future cost of SF6 itself is a significant factor. The
cost of SF6 has doubled for Cooper Power Systems in
less than 3 years.
While ratification of the Kyoto Protocol by the United
States and other countries may not occur for several
years, interim domestic United States restrictions and
regulations may be enacted.
For utilities that do not currently utilize SF6 equipment,
the introduction of SF6 gear will require the purchase of
additional equipment and personnel training.
Depending upon the degree of inspection and maintenance necessary, utilities may choose to contract this
specialized work to a third-party service company, at a
significant expense. In either case, more frequent
inspection will be required to monitor possible gas
leakage. Where SF6 leakage occurs, equipment changeout may be required, or costly equipment will be
required for on-site maintenance. Utilities that currently utilize SF6 equipment will require additional inspection and maintenance.
Joint efforts continue between the United States’ government, utilities, and utility equipment manufacturers
to comply with the Kyoto Protocol. Key to these efforts
is the gathering of statistical data on the use of SF6,
OEM and user inventory accounting of SF6, development of voluntary programs for the reductions of SF6
emissions, the promotion of programs for user training
in the use and handling of SF6, and representation of
the electric power industry to governmental bodies.
These activities should cause utilities to anticipate
future restrictions and regulations in the use of SF6.
Release of SF6 to the atmosphere will almost certainly
be scrutinized. Control and reduction of leakage rates,
inventory and control of SF6 suppliers, training and
certification of technicians, and detailed record keeping
will almost certainly result.
SF6 Costs Add Up
Though purely speculative at this time, and since few
regulations currently exist, potential or unexplored
costs for SF6 maintenance and handling equipment can
be high for even the smallest utilities.
Gas Cart: Required if a utility performs basic inspection and maintenance, such as maintaining required
pressure on leaking units, opening units for inspection
and repair without venting SF6 to the atmosphere,
recharging and cleaning SF6 gas in older units.
Cost: $30,000 - $40,000.
Kyle Distribution Switchgear, for example, has been
asked to monitor its SF6 inventory for the past three
years. Kyle’s SF6 inventory system records the amount
of SF6 purchased, as well as the amount shipped in
switchgear. This system provides the capability of identifying any lost SF6 during handling.
Hygrometer (moisture detector): Cost: $2,000 - $5,000.
Kyle, like any manufacturer, responds to market
demand for SF6 products, but looks to explore alternative insulation options as they are developed.
Halogen Leak Detector: Cost: $500 - $1,000.
Gas Sampling Equipment: Cost: $2,000 (part of gas
cart, or can be purchased separately).
Toxic Waste
SF6 Inventory: Cost: To maintain inventory of SF6 for
maintenance and repair.
Some equipment utilizes the same SF6 gas for both
interruption and insulation. Current interruption in SF6
results in a toxic residue in the form of white powder.
This extremely hazardous material currently requires
careful, controlled methods for handling, cleaning and
disposal. Switchgear that does not utilize SF6 for current interruption will also produce this toxic residue
with any failure involving internal arcing.
Safety, training, and future regulation are unknown
costs that should not be overlooked.
3
SF6
Synopsis of Recent
World-Wide Activities
that the Global Warning Potential (GWP) of SF6 is
24,900 compared to CO2 at 1 and methane at 24.5, and
the emissions of SF6 reached 1,030 metric tons. Also
projected was the increased use of SF6 due to the
phase-out of CFC’s per the 1987 and 1992 Montreal
Protocol and 1990 United States’ Clean Air Act
Amendments.
1992 - An international conference was held in Geneva,
Switzerland in which a consortium of countries, including the United States, agreed to voluntarily reduce SF6.
February 1995 - World Resource Institute (WRI) published the article, “Why Climate Policy Makers Can’t
Afford to Overlook Fully Fluorinated Compounds.”
The WRI cited the assessment of the Intergovernmental
Panel on Climate Change (IPCC), stating “SF6 is the
most potent greenhouse gas ever evaluated by the
IPCC, with atmospheric lifetimes from 3,200 to 50,000
years.”
July 1996 - Second Geneva Conference concluded that,
based upon the most recent research relating SF6 to the
global greenhouse effect, the 1992 voluntary measures
were inadequate for environmental protection.
July 1996 - The United States’ delegation to the Second
Geneva Convention committed to immediately prepare
a voluntary compliance program for SF6 emissions with
mandatory regulation as the final goal.
April 1995 - IEC released a technical report (160 pages)
on the handling of SF6 in high voltage switchgear and
control gear.
December 1997 - Kyoto Conference resulted in the
Kyoto Protocol. The Kyoto Protocol recommended that
countries take action to reduce the emissions of all
greenhouse gases by specified levels. SF6 is considered
a prime target for strict control.
July 1995 - Conference on Electrical Transmission and
Distribution Systems - “SF6 and the Atmospheric
Effects of Greenhouse Gas Emissions” - Washington
D.C. - Chaired by Elizabeth Dutrow, United States
Environmental Protection Agency (EPA), in response to
President Clinton’s directive to develop a Climate
Change Action Plan to decrease greenhouse gas emissions. At this Conference, the United States’ EPA
announced their plan to begin the development of a
voluntary program for users of SF6 in electrical transmission and distribution systems.
Kyle NOVA Technology Leads
Industry
Cooper Power Systems’ Kyle Distribution Switchgear
leads the electric power industry with its NOVA family
of switchgear products (reclosers, switches, sectionalizers). NOVA products utilize a state-of-the-art design
which completely replaces liquid and gas dielectric
mediums. Environmentally-friendly and maintenancefree, the future is here with NOVA.
January 1996 - United States’ EPA released a document
in accordance with the Framework Convention on
Climate Change (FCCC), “Inventory of Greenhouse
Gas Emission and Sinks 1990-1994.” The EPA stated
P.O. Box 1640
Waukesha, WI 53187 USA
www.cooperpower.com
©1998 Cooper Power Systems, Inc.
Kyle® is a registered trademark of Cooper Industries, Inc.
NOVA™ is a trademark of Cooper Industries, Inc.
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Bulletin 98012 • March 1998 • New Issue
KTM
3/98