How does electricity reach a home?

A lamp at home can use energy supplied far away because a connected electricity network carries power from generators to users. Transmission serves the longer journey; distribution serves local homes and other buildings. Changing voltage along that route helps deliver power with less wire heating.

Transformers change alternating-current, or AC, voltage between stages. Voltage describes the electrical push associated with energy transfer per unit of charge. For the same transferred power, raising voltage permits a smaller current, meaning less charge passing a point each second. Wires have resistance: moving charge transfers some energy to their material, heating it. Less current greatly reduces that unwanted heating, so more of the supplied power can reach users.

Step-down transformers lower voltage again for local distribution and use. They transfer energy rather than creating it: an ideal increase in voltage is paired with a decrease in current for the same power. Distribution connections then carry power toward homes and other users.

The home needs a connected route as well as a working source. Breaking its only drawn branch interrupts delivery even while generation continues. Real grids join many sources and users, sometimes with alternative routes; whether a particular home can still receive power depends on those connections and equipment. This illustration explains network roles rather than calculating a complete grid.