TRANSFORMING
the transformer
industry
Vegetable oil-based transformer fluids increasingly are
replacing mineral oil-based products in the marketplace.
They are succeeding because they perform better than
mineral oil products and are environmentally preferable.
Catherine Watkins
Twelve years after its first real-world
test, vegetable oil-based dielectric fluid
arguably is the most successful nichemarket biobased product in the world.
The story of how natural ester fluids,
as they are known, moved from lab
scale to being used by electrical utilities in 27 countries is a case study in
successful commercialization.
August 2008 inform
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THE MARKET
Transformers are virtually everywhere,
and virtually every distribution and power class transformer is filled with dielectric
insulating fluid, which exhibits high resistance to electricity and insulates and cools
the transformer.
Dielectric fluids have traditionally
been manufactured from mineral oil. Polemounted transformers such as the unit
shown on this page contain about 25 gallons, or almost 95 liters, of fluid. Substations use between 10,000 and 20,000 gallons. Multiply that over the entire global
electrical grid and it becomes clear that the
potential market for biobased transformer
fluids is huge.
“In the United States, we generally
see about 75 million gallons of new oil
sold each year for new transformers by all
manufacturers and service/repair companies,” said Gene Del Fiacco, a senior global application engineer with Cooper Power
Systems in Waukesha, Wisconsin, USA.
Cooper is a division of Cooper Industries,
Ltd., and manufactures the leading line of
biobased dielectric fluids: Envirotemp ®
FR3 ®. “Globally, about 1.5 million gallons of new oil are sold annually. All of
the old, installed transformers in the United States contain over 2 billion gallons of
dielectric fluid.”
THE DEVELOPMENT
Several lines of research involving a number of AOCS members have resulted in the
two main products on the North American
market—Cooper’s Envirotemp FR3, which
is soy-based (although other oils could be
used), and ABB Inc.’s BIOTEMP®. BIOTEMP is manufactured from high-oleic
sunflower oil, although safflower oil can
also be used, according to Stephane Page,
ABB’s business manager of specialty fluids. ABB Inc. is an affiliate of the Swissbased ABB Group; BIOTEMP is manufactured at the company’s South Boston,
Virginia, facility.
INDUSTRIAL OIL PRODUCTS
The projected market for FR3 fluid-filled
transformers in the United States by year
end is 150,000 units, according to Cooper Power Systems, which developed and
sells the natural ester dielectric fluid. The
company also says that the market share
for natural ester fluids currently is around
10% in the United States. Image courtesy
of Cooper Power Systems.
electric fluid with one that would be environmentally preferred,” he explains. “Over
the course of the years, development of FR3
fluid was safety driven, both in terms of its
biodegradability and higher fire point,” he
notes. (Petroleum-based fluids have a fire
point of about 145°C; natural ester fluids
have a fire point above 300°C.)
Cooper spent “a lot of time and money” in overcoming the inherent instability of vegetable oils. The formula is proprietary, but the basic feedstock is refined,
bleached, and deodorized soy oil with a
“small amount” of nontoxic additives for
better pour-point characteristics and oxidative stability. That, and a touch of green
food dye to differentiate the product from
petroleum-based fluids. Although Cooper
has been using soy oil as the base, McShane says other oils can be used as the
economics dictate, including rape or canola, as well as palm oil “with some additional development work.”
A third product—BioTrans—is no
longer on the market. It was developed by
Glenn Cannon, who formerly was general manager of Waverly Light and Power™
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August 2008 inform
Cooling and insulating fluids for transformers were made for more than a century from mineral oils derived from crude
petroleum. Such oils have good dielectric
strength but are flammable at 145°C. Beginning in the 1930s, PCBs (polychlorinated biphenyl fluids) replaced mineral oils in
fire-sensitive areas and applications.
Once the environmental hazards of
PCBs were known, their use in new equipment was banned in 1976. Thus, the search
for environmentally benign replacements
began. Synthetic polyol esters formed by
the processing of fatty acids and alcohols
have been used as a substitute for PCBs in
transformer fluids since the early 1980s.
Even before that, however, Clair Claiborne of ABB remembers that Westinghouse, ABB’s predecessor company, was
approached by a Native American tribe,
suggesting research on jojoba oil. That idea
“never went anywhere,” he said, until early 1995, when a large, Northeastern utility
complained to him that they were spending
millions of dollars on clean-ups of mineral
oil spills from downed transformers.
With a potential customer on hand,
Claiborne—who is the co-inventor of BIOTEMP with Thottathil V. Oommen and
currently is a principal consulting R&D
scientist with ABB—conferred with Ken
Carlson at the U.S. Department of Agriculture and visited the Texas A&M pilot
plant. Claiborne ordered various types of
oils available at the time, including meadowfoam and crambe, and began working
to create a functional natural ester dielectric fluid.
“We quickly arrived at high-oleic acid
oil as optimal because of its relative oxidative stability,” Claiborne recounts. “We
put the first units using natural ester fluid
into the field in 1999 and we have been developing the fluid ever since.” BIOTEMP
sales “have grown substantially over the
past five years,” according to Don Cherry,
ABB’s technical specialist dielectric fl uids, “and BIOTEMP-filled transformers
now comprise approximately 20% of our
revenue in South Boston, Virginia.”
The story of development at Cooper
Power Systems is similar. Envirotemp FR3
inventor and AOCS member C. Patrick
McShane, who is currently Cooper’s global
technology manager and global technical
manager for dielectric fluids, began work
on developing the company’s natural ester
dielectric fluid in 1992.
“The motivation for us was to replace
our fire-resistant but petroleum-based di-
ABIL becomes NABL: An update
Early work on biobased transformer fluids (and more than
30 other products) was completed by AOCS member Lou
Honary and his team at the University of Northern Iowa
(UNI) in Waverly (USA), where Honary established the AgBased Industrial Lubricants (ABIL) Research Program in
1991.
In January 2006, ABIL was given an expanded mission
and was renamed the National Agriculture-Based Lubricants
Center (NABL). Whereas before 2006 the focus was on the
1.1-billion-gallon (approximately 4.2-billion-liter) U.S. industrial lubricant markets, now the scope includes the complete 2.6-billion-gallon U.S. lubricants market, including automotive lubricants.
Among other projects, NABL is working on a soy-based
wood preservative, Honary said.
“Very soon in Iowa we will be seeing signposts using
the preservative,” he noted. “There is also a lot of interest
in this product as a creosote substitute for utility poles and
railroad ties.”
NABL has installed a full line of equipment to handle
biofuels testing in support of the biodiesel industry and will
soon begin testing engine oils.
“We are working with growers and agronomists to
come up with oilseeds that will have utility in engine oils,”
he said. “Then we plan to work with additive companies and
engine manufacturers to develop the best performance possible.”
August 2008 inform
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(WL&P) in Waverly, Iowa, and now heads
the Step Up coalition. Step Up, which
stands for Safer Transformers, Environmental Protection, and Upgraded Performance, aims to foster the adoption of natural ester dielectric fluids by industry. The
coalition’s home on the web is www.safertransformers.org.
Cannon worked with AOCS member Lou Honary (see sidebar, above) to
develop BioTrans, a soy-based dielectric
fluid that was first used in 1997 to retrofill
WL&P’s transformers. Cargill’s Industrial Oils and Lubricants division purchased
Waverly’s technology and patents in 2000.
When Cooper Power Systems determined
that the Cargill and ABB technologies
were infringing on Cooper’s patents, Cooper successfully defended them, eventually licensing the technology to ABB and
forming an alliance with Cargill in August
2004. The economies of scale afforded by
a technical and commercial alliance with
Cargill “have proven to be very positive
for both companies,” McShane says. Industry reports suggest Cargill is now already manufacturing or preparing to manufacture FR3 fluid in facilities in Wichita,
Karl Goldsmith, an intern at the National Agriculture-Based Lubricants (NABL) Center, inspects a railroad tie after pressuretreating it with a new vegetable oil-based wood preservative at
the NABL Center’s Waverly, Iowa, research facility. Image courtesy of NABL
More information about NABL—and Environmental Lubricants Manufacturing Inc., the for-profit spin-off created by
the UNI Foundation and Honary to commercialize a number of biobased products—is available at www.uni.edu/nabl
and www.elmusa.com, respectively.
Kansas; south Chicago, Illinois; and Brazil, with other countries to follow as demand dictates.
THE PLUSES
Studies on the long-term behavior of natural ester fluids in transformers have had
interesting results, McShane says. “We
learned it had other favorable attributes.
The most striking was that it greatly extended the life of the cellulose-based insulating paper in transformers. Over time,
that paper normally becomes brittle and
the cellulose begins to break down, leading to equipment malfunction.”
Tests showed that natural ester fluids
extend paper life by four to eight times
when it is aged in the fluids. Thus, use of
natural ester fl uids leads to a lower total
life cycle cost for transformers—a powerful selling point. In addition, the risk of
transformer fires is significantly reduced
because of the higher fire point of natural
ester fluids.
Finally, natural ester fluids are completely biodegradable, making them particularly suited for environmentally sen-
sitive applications and potentially saving
electrical utilities millions of dollars in
clean-up costs.
“The push for sustainability is sweeping the globe,” Patrick McShane says.
“Natural ester fluids will supplant mineral oil. It is just a matter of time.”
Catherine Watkins is associate editor of
inform. She can be reached at cwatkins@aocs.org.
information
IEEE PC57.147—Guide for Acceptance
and Maintenance of Natural Ester Fluids in Transformers—was approved on
May 18, 2008, by the Institute of Electrical and Electronics Engineers’ (IEEE)
Natural Ester-based Fluids Working
Group and was published as a final
standard on July 11, 2008. For more
information, see www.ieee.org.