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Smart Grid

Office of Electricity and Energy Reliability; DOE

Smart Grid

The vast and complex network of infrastructure that conveys electricity from power plants to end users, known collectively as “the grid,” combines more than 19,000 sources with a capacity of 1 trillion watts of power and more than 450,000 miles of transmission and distribution lines.

It has transformed society. The National Academy of Engineering selected it as the single most significant engineering achievement of the twentieth century. Yet nearly all of this aging system was built before the advent of microelectronics and ultra-sensitive detectors. The grid takes advantage of few of the kinds of remote sensing, real-time monitoring, automated analysis and control, and high-speed information exchange that have prompted huge efficiency gains in other sectors of American society. 

In its present form, the grid is vulnerable to power outages and interruptions costing as much as $150 billion per year.

In its present form, the grid is vulnerable to power outages and interruptions costing as much as $150 billion per year, has a highly centralized architecture, has not kept pace with increasing demand, and has limited ability to track developments as they occur. In many areas, a utility does not know there has been an outage until a customer calls.

But change may be on the way in the form of a planned nationwide “Smart Grid” that will combine modern real-time sensors, integrated Internet/wireless communication, and automated switching with oversight technologies that will make it much easier to manage fluctuations in demand and integrate new, intermittent power sources such as wind and photovoltaic generators.

The Smart Grid will be more decentralized (distributed generation is less open to widespread failure or terrorist attack), employ advanced metering and end-user controllers that respond to near instantaneous changes in electricity prices, sample line conditions dozens of times per second, and feature visualization schemes that can show conditions in an entire grid sector or on an individual street.

Unlike other utilities such as water, electricity has to be used the moment it is generated. It cannot readily be stored. So meeting peak demand usually means bringing additional (often expensive) auxiliary power plants on line for an indeterminate period. A Smart Grid’s real-time analysis and control systems would make it easier to reduce power for non-critical uses during peak demand and to route power between areas of differing demand. Real-time monitoring, automation, high-speed interconnectivity, distributed generation, and fine-grained control of energy flow could allow utilities to send between 50% and 300% more electricity over existing infrastructure, according to the U.S. Department of Energy (DOE).

Full Smart Grid implementation will require many years and many tens of billions of dollars. But much is happening now, thanks to expenditures by utilities as well as federal and other government support, and even incremental progress can be significant. Making the existing grid 5% more efficient, the DOE projects, “would equate to permanently eliminating the fuel and greenhouse gas emissions from 53 million cars.”

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