Fundamentals
There are two types of current. One is direct current (DC) and the other is alternating current (AC). Direct current always keeps the same direction. Alternating current always switches its direction.
Generation
| Source | Type | Usage |
|---|---|---|
| Power plants | Alternating current (three-phases) |
– Transported via the grid to the consumer |
| Photovoltaic systems | Direct current | – Stored in a local battery – Fed into the grid (requires an inverter) |
Consumption
- A household receives three-phase alternating current from the grid.
- Some components require three-phase AC: cooking plate (kitchen), charging station (electric car), others require single-phase AC: ceiling lights and wall sockets.
- Some devices connected via a wall socket actually need single-phase AC: washing machine, oven and some need DC: smartphone, PC (requires a rectifier).