An electrical substation is a subsidiary station of an electricity generation, transmission, and distribution system where voltage is transformed from high to low or the reverse using transformers. Electric power may flow through several substations between generating plant and consumer and may be changed in voltage in several steps. Substations may be owned and operated by an electrical utility or may be owned by a large industrial or commercial customer. Generally, substations are unattended, relying on SCADA for remote supervision and control.