Environmental Engineering Reference
In-Depth Information
revised its forecast, predicting a great leap forward, and a 25 per cent share by 2030. Not
all observers are convinced that the current growth of renewables is sustainable. According
to Smil, “Such high growth rates are typical of systems in early stages of development,
particularly when the growth has been driven primarily by subsidies. Projections of
wind-power generation into the future have been misleadingly optimistic, because they are
all based on initial increases from a minuscule base” ( 2012 ) .
A Smarter Grid
In August 2003, several power lines in northern Ohio brushed against overgrown trees and
shut down. The alarm software failed, leaving local operators unaware of the problem.
Transmission lines surrounding the failure spot, already fully loaded, were forced to bear
more than their safe quota of electricity. A power plant automatically shut down in response,
destabilising the system's equilibrium. More lines and more plants dropped out. The cascade
continued, faster than operators could control, and within eight minutes the largest blackout
in North American history occurred, leaving 50 million people across eight states and two
Canadian provinces without power. In the following two months, major blackouts also
occurred in the United Kingdom, Denmark, Sweden and Italy (Massoud and Schewe 2008 ).
Today's power grid evolved in the early 1900s when localised grids were constructed and
eventually connected to each other. The idea of having a national electricity grid was to allow
regions with surplus capacity to export their power to regions with a deficit. By the 1960s,
the electric grids of developed countries had become very large and highly interconnected,
reaching the overwhelming majority of the population. In acknowledgement of its ability
to improve people's lives by transforming diverse sources of primary energy into a clean,
controllable energy carrier capable of being transmitted over long distances, the power grid
was voted “the greatest engineering achievement of the 20th Century” by the American
National Academy of Engineering (NAE 2000 ) .
Power grids, as they are currently conceived, deliver power in one direction, from
centralized power stations via high-capacity power lines branched to supply industrial and
domestic users. Power stations are strategically located close to reserves or supply lines
(mines, wells, railways, rivers or ports). However, as consumption grows and energy supply
diversifies, more sophisticated control systems become necessary. Electrical engineers
foresee a future in which the power grid is integrated with information technologies and
the Internet. Such a 'smart grid' would ensure a more reliable supply of electricity, reduce
vulnerability tonatural disasters orterrorist attacks, andfacilitate aswitch fromthetraditional
unidirectional supply based on large power stations to the two-way flow of intermittent,
decentralized and small-scale renewable power production (Behr and ClimateWire 2011 ) .
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