Environmental Engineering Reference
In-Depth Information
economic growth rate and reducing the cost to consumers for power
disturbances. Economic output (gross domestic product per capita) is
strongly correlated with the consumption of electric power.
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The need for alternative sources of energy to supplement or replace
fossil fuels has been well publicized, but the need for new electric trans-
mission lines has not. Many transmission lines and the connections
between them are too small for the amount of power that companies
would like to squeeze through them. The diffi culty is most acute for
long-distance transmission but shows up at times even over distances of
a few hundred miles. The power grid is fragmented, with about 200,000
miles of power lines supporting 830 gigawatts, and divided among 500
owners. Built gradually over time, the grid exists as a patchwork of
remedies rather than a singular coordinated unit. Big transmission
upgrades often involve many companies, many state governments, and
numerous permits, and every addition to the grid provokes fi ghts with
property owners. These barriers have caused electrical generation to
grow four times faster than the ability of the grid to transmit it. Modern-
izing the electric infrastructure is an urgent national problem. The aging
system cannot indefi nitely sustain the nation's demand for electricity,
which is growing at 2 percent per year.
The electrical grid in the United States is divided into 140 balancing
areas, some overseeing as little as 100 megawatts and others more than
100 gigawatts, a thousand times more. Grid operators balance supply
and demand in each area and oversee the fl ow of power through their
individual systems. An area may have too much supply at a time when a
neighboring area is running short. But the oversupplied area may not be
able to assist the undersupplied area because of transmission constraints
that exist between the two regions.
What is required is a smart grid—an electrical transmission network
with these features:
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•
Intelligent. Capable of sensing system overloads and rerouting power
to prevent or minimize a potential outage; of working autonomously
when conditions require resolution faster than humans can respond,
and cooperatively in aligning the goals of utilities, consumers, and
regulators.
•
Effi cient. Capable of meeting increased consumer demand without
adding infrastructure.
•
Accommodating. Accepting energy from any fuel source and capable
of integrating any better ideas and technologies as they are market
proven and ready to come online.
