02-08-2011, 03:32 PM
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What is The Smart Grid?
1.1 Smart Grid
A smart grid, as in figure 1.1.1 is a form of electricity network using digital
technology. A smart grid delivers electricity from suppliers to consumers using two-way
digital communications to control appliances at consumers' homes; this could save energy,
reduce costs and increase reliability and transparency if the risks inherent in executing
massive information technology projects are avoided. The "Smart Grid" is envisioned to
overlay the ordinary electrical grid with an information and net metering system, which
includes smart meters. Smart grids are being promoted by many governments as a way of
addressing energy independence, global warming and emergency resilience issues.
The idea of two way communications from suppliers to consumers to control
appliances is not new, and systems have been implemented using analog technology for many
years. The growth of an extensive digital communication network for the internet has made it
practical to consider a more sophisticated type of smart grid. The increased data transmission
capacity has made it conceptually possible to apply sensing, measurement and control
devices with two-way communications to electricity production, transmission, distribution
and consumption parts of the power grid at a more granular level than previously. These
devices could communicate information about grid condition to system users, operators and
automated devices, making it possible for the average consumer to dynamically respond to
changes in grid condition, instead of only utilities and very large customers.
Like existing utility grids, a smart grid includes an intelligent monitoring system that
keeps track of all electricity flowing in the system, but in more detail. Like the existing grid,
it also has the capability of integrating renewable electricity such as solar and wind, but has
the potential to do so more effectively. When power is least expensive the user can allow the
smart grid to turn on selected home appliances such as washing machines or factory
processes that can run at arbitrary hours. At peak times it could turn off selected appliances to
reduce demand. There are many technical obstacles to be overcome to make this practical for
the average homeowner; for example, if wind speeds decrease in the middle of a wash cycle,
would consumers want their laundry.
A widely overlooked fact about the smart grid is that it is not a substitute for a real
grid, but only an enhancement. The construction of a larger and better infrastructure of highvoltage
transmission lines for the efficient delivery of electric power is a prerequisite to the
construction of an effective smart grid.