Electric Transmission 101: How the Grid Works

• Today's transmission grid is a highly integrated, interconnected system that transmits electricity from the site of generation—where electricity is "created"—to the load—where it is used by "consumers."
• Transmission moves power long distances from generators to load with some loss of energy. High interconnectivity increases reliability.
• Unlike highways, pipelines, and telecom, the flow of electricity cannot be routed or controlled. Power flows via the path of least resistance. This is a critical difference in how the grid differs from other transportation mechanisms.
• Power systems are interconnected across large areas. There are 8 regions and 135 balancing authorities within the three major interconnections: Western (West of the Rockies), Eastern (East of the Rockies), and Ercot (Texas).
• Transmission is regulated by a number of federal, regional, state and local entities. These entities oversee operations, development, planning, siting, reliability, and ratemaking. State regulations play a very significant role, and vary state-to-state.
• The transmission system is essential to delivering remote clean energy resources, where the site of generation is often rural landscapes with good sun or wind resources far from electricity demand.
• Billions of dollars of transmission investment will be needed to keep up with the predicted short-term electricity demand and to provide interconnection for expanded electricity generation from both renewable and conventional sources.