ARGUMENTS FOR ENERGY INDEPENDENCE IN the United States have generally focused on sources of fuel. Before the widespread use of hydraulic
fracturing, the U.S. economy relied on
increasing levels of petroleum imports.
That part of the country’s energy supply
was subject to disruptions for reasons
ranging from embargoes to foreign wars.
Less widely discussed was another side of the energy independence issue, involving not fuel but a critical link in the delivery of energy: Specifically the huge
transformers that step up voltage for long-distance
transmission, and equally large transformers that step
voltage down as electricity makes its way to customers.
In the fear that gripped the country after September
11, 2001, those transformers were seen as a vulnerability. They took months to replace. They are rated to
handle several hundred megavolt-amperes of electricity, and they are custom engineered and built.
There were only two factories in the United States
that built them. Most of those transformers, possibly
95 percent of them, were imported. If enough of them
were destroyed, it could plunge regions of the U.S.
into blackouts that could last weeks or months before
power could be fully restored.
One possible solution was a test program involving
the Department of Homeland Security and other government agencies to design an emergency transformer
that could serve as an interim replacement. A demonstration was successful and the program is ending.
Meanwhile, the number of companies building big
transformers in the United States has more than doubled
since that program began. Manufacturing capacity near
the point of delivery is expected to reduce lead times
and reduce the need to rely on imported transformers.
Plants have been opened by three of the largest over-
seas manufacturers of grid transformers: Mitsubishi
Electric Power Products, Hyundai Heavy Industries,
An industry-government partnership
installed RecX, a prototype emergency
transformer, at a CenterPoint Energy
substation near Houston in March 2012.
Image: Electric Power Research Institute