Environmental Engineering Reference
In-Depth Information
Dollar Costs of Utilizing Electric Power
The bulk electric power system in the United States represents more than $1 trillion worth of
generating and transmission assets (NERC 2011b). Transmission lines are expensive to build, with
double-circuit high-voltage lines costing about $369,000 to $1.9 million per mile on flat land in
rural settings (Ng 2009, 4; Colorado Long-Range Transmission Planning Group 2004, Appendix
F) and 345kV lines costing about $615,000 to $2.6 million per mile in dollars adjusted to 2010
(Long-Range Transmission Planning Group 2004, Appendix F; American Electric Power 2008).
A single transmission tower may cost upwards of $30,000, and a corner tower $50,000. Transmis-
sion corridors built on hilly, forested, suburban, or urban terrain cost significantly more per mile
than those built on flat, unforested, or uninhabited land. Even removal of transmission lines is
expensive, often costing $468,000 or more per mile in 2010 dollars for double-circuit high-voltage
lines (American Electric Power 2008). Generating facilities located adjacent to consumers avoid
these costs. Federal subsidies and tax expenditures for improvements to electricity transmission
were estimated at $971 million for FY2010, reduced from almost $1.1 billion in FY2007 (USEIA
2011a, xiii, xviii).
Blackouts, discussed below as an indicator of vulnerability of the transmission system and a
national security cost, are also an expensive drain on the economy. The total direct and indirect cost
to the national economy of the major blackout in eight northeastern states and two Canadian prov-
inces in 2003 was estimated at US$6.8 to US$10.3 billion (ICF Consulting 2003). Some estimate
the costs of electric power outages at $26 billion per year in the United States (Casazza and Delea
2003), while others estimate that blackouts cost the nation about $80 billion annually (Lawrence
Berkeley National Laboratory 2005). The Electric Power Research Institute estimates that power
outages and low power quality cost the economy over $119 billion per year (EPRI 2001).
National Security Costs of Electric Power
Alternating current flows one direction and then reverses direction and flows the opposite way, while
direct current flows in only one direction. The nature of alternating-current electrical technologies
used in a U.S. bulk electric power system makes it peculiarly susceptible to sabotage:
Throughout the grid, the alternating electric current must change its direction of flow back and
forth at an essentially constant rate, which in North America is sixty cycles per second: this con-
stancy is called “frequency stability.” Stability of voltage—the amount of electrical “pressure”
in the line (as opposed to current, the amount of electrical flow)—is vital to avoid damage to
equipment. Power is transmitted over three parallel lines, each bearing a precise time relationship
to the others—somewhat akin to singing a three-part round. The “phase stability” among these
different lines, and between voltage and current, must also be maintained. And these exacting
relationships must be kept in step with each other in all parts of the grid at once (“synchroniza-
tion”). (Lovins and Lovins 1982, 123)
When adding new generating capacity to an existing grid, care must be taken to configure
connections and other features of the grid to preserve frequency stability, phase stability, and
synchronization. Sometimes this requires building transmission lines between other parts of the
grid besides those lines that connect new capacity directly to it.
Moreover, in an interconnected electric grid, everything happens very fast. If frequency stability,
phase stability, or synchronization is disrupted, control response is often required in thousandths of
 
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