Getting Smart: Page 2 of 4

Utility Overloads

Power companies will be able to more effectively monitor their portion of the grid for trouble spots and for impending overload conditions. When a major section of a power distribution system becomes threatened with overload, power companies can now redistribute energy by remote control to meet the demand. The time-consuming tasks of manually doing so are being phased out for a more automated approach that acts before crisis.

Just as in a home power system where increased current flow through a wire means increased voltage loss, when a portion of the grid or a local or regional distribution system experiences a heavy electrical load, significant energy is lost in the components of that system, including the energy sources, transformers, other equipment, and transmission lines. The line voltages drop, which decreases the voltage delivered to the customers. This causes appliances to run inefficiently, further increasing current draw. If some of the loading is not shed quickly enough, that portion of the grid can go under, meaning that overload prevention mechanisms simply cut off power or system components fail (lines, fuses, transformers), creating a blackout situation. During times of extreme load, power companies sometimes deliberately create rolling blackouts to prevent the failure of a larger section of the distribution network.

Unlike a conventional grid, a smart grid takes action to preempt overloads, which include immediate and stepped load shedding, or bringing additional generating capacity on line. These strategies are typically performed without the customer being aware.

System-wide energy efficiency and conservation are greatly improved in a smart grid because the balance between loading and power generation can be controlled more easily and precisely. For example, instead of bringing on line more electrical generation capacity that uses more energy, the existing capacity can be made sufficient through discriminate load shedding, in which heavy-load appliances, such as air conditioning and water heating, are turned off for short periods of time. Load shedding can be distributed across a city or vast region in a rotational wave that prevents brownouts, while largely unaffecting customers.

Advanced Metering Infrastructure

The U.S. Department of Energy’s National Energy Technology Laboratory has defined a massive upgrade to the electrical power system under the banner of the AMI—the convergence of many communications, automation, and data-processing technologies. The AMI provides information to consumers so that they can make wise energy-usage decisions, and allows power companies to make power-distribution decisions. Combined, these strategies are designed to reduce energy needs and conserve energy resources. The key benefits of AMI include:

For Consumers

• Gives consumers a real-time view of energy usage and cost
• Empowers consumers to make educated decisions about energy use
• Gives consumers more control over their electric bills

For Utilities

• Remote meter reading
• Real-time consumer usage data
• Remote load shedding inside customer premises
• Remote activation or deactivation of service

For Both Consumers & Utilities

• Real-time usage awareness and responses
• Fewer brownouts
• Fewer blackouts
• Cost savings from more efficient use of power infrastructure