The electrical grid is a set of wires, devices and installations. It is used to transmit, process, and distribute electricity generated at power stations and supply it to customers.
The electrical grid consists of:
- Power stations. Power stations are industrial plants that produce electricity from different primary energy sources, such as coal, natural gas, and oil.
- Electric power transmissions. Electric power transmissions carry electrical energy over long distances (high voltage).
- Substations. Substations transform voltage from high to low, or in reverse.
- Electric power distributions. Electric power distributions provide electricity to individual customers (low voltage).
Electrical grids are designed to supply AC current to their customers at largely constant voltages and frequency. In the United States, the nominal voltage and frequency of power delivered to customers are 120V and 60Hz. In Europe, the nominal voltage and frequency of power delivered are 230V and 50Hz.