The US electric grid is made up of three major complex grids that provide energy to over 300 million residents. Together, the three grids operate as a giant one-way energy highway. Electricity moves from energy centers to high voltage transmission lines, then to lower voltage power lines, which distribute the electricity to homes, schools, businesses and neighborhood streets.
Energy centers, no matter what resource they use to make electricity, feed into the same grid - the energy mixes together, and flows out from the grid as needed. This co-mingling of energy sources ensures a reliable flow of power, even if one source of power goes out or temporarily shuts down. For example, if the wind stops blowing, there is still enough energy coming from other power sources to satisfy demand. Having diversified energy sources helps the grid remain reliable.
Today, it is becoming more common to add power through what is called “distributed generation”. Distributed generation refers to power that is produced at smaller-scale projects located closer to the end user, rather than large remote energy centers. Distributed generation might include small-scale wind farms, natural gas turbines, or rooftop solar on a local school or business. Although these projects can't produce enough electricity to power the entire neighborhood or area, distributed generation resources work with the large energy centers to provide a diverse mix of power to meet customer electricity needs around the clock.