The Smart Grid
Definitions abound for the Smart Grid, but all contain common elements.
The Smart Grid refers to the introduction of new information and control technologies to the electricity system that allows the system to be planned and operated in a dynamically-optimized manner. An example of such technology is the smart meter, which provides new information and communication ability for utilities and consumers to use to better manage and reduce the cost of their business operations and energy consumption. Another example is new sensor and control systems that automate and increase the operational efficiency of substations and other parts of the utility infrastructure.
The smart grid is not limited, however, to infrastructure or the smart meter. It reaches into the home or business by way of new pricing, control, and information options that help users reduce their electricity usage and their bill. It will also connect to smart appliances that automatically accept price and control signals that allow them to be used in a way that better supports energy efficiency.
Demand Response, for example, is the practice of incentivizing customers to modify their electricity usage in ways that help make the electric grid more efficient and reliable, particularly during periods of peak demand. Because demand response reduces peak demand, it complements intermittent and variable resources that tend to be available more during off-peak periods, such as wind energy. Demand response, in this way, supports the use of greater amounts of renewable energy.
The smart grid also includes important new technologies such as energy storage and plug-in hybrid electric vehicles (PHEVs). Energy storage is a form of demand response that allows renewable energy to be used not only when it is produced but also when it is needed. With storage options, peak demand can be met by renewable energy generated during off-peak periods. PHEVs, meanwhile, have the potential to be mobile energy storage units. They charge from the grid, store electricity they don’t use, and have the ability to return excess electricity to the grid during peak demand periods.
While no official definition of the smart grid exists, Section 1301 of the Energy Independence and Security Act (EISA), passed by Congress and signed into law by President Bush in 2007, is considered to be a good description of the types of technologies and practices that compose the Smart Grid. Smartgrid.gov, a project by the U.S. Department of Energy, contains a good description of and background information on the smart grid.