A power plant is an industrial facility that generates electricity from primary energy. Most power plants use one or more generators that convert mechanical energy into electrical energy in order to power the electrical grid and, in turn, supply society's electrical needs. The exception is solar power plants, which use photovoltaic cells to generate this electricity.
The type of fuel or flow that gives a power plant its primary energy varies. The most common fuels are coal, natural gas, and uranium (nuclear power). By far the most important primary energy flow for electricity generation is hydroelectricity (water). Other flows that are used to generate electricity include wind, solar, geothermal and tidal.
Different countries get their electricity from different types of power plants. For example, in Canada, most electricity generation comes from hydroelectric power plants which account for about 63% of the total electricity generated in Canada. Please see the data visualization below to explore how countries around the world get their electricity.
Most thermal power plants use their fuel to generate steam from a reservoir of water, usually at a high pressure. The highly pressurized steam then travels through pipes to turn the fan-like blades of a turbine (see Rankine cycle for more info). As the turbine begins to spin, it causes giant wire coils inside the generator to turn. This creates relative motion between a coil of wire and a magnet, which pushes electrons and starts the flow of electricity.
Thermal power plants are all limited by the second law of thermodynamics, which means they cannot transform all of their heat energy into electricity. This limits their efficiencies, which can be read about on the Carnot efficiency and entropy pages.
Renewable energy power plants get their energy directly from their respective flows in order to generate electricity. These primary energy sources replenish themselves eventually, but are limited in the amount of energy that is available at any given time or place, therefore they are often intermittent and non-dispatchable.
Once electricity is generated, transformers "step-up" the electric power to a higher voltage in order to travel long distances with minimal energy loss. It then travels through "pylons" along overhead power cables to its destination, where transformers subsequently "step-down" the electric power to safe voltages for houses and utilities. For a more complete story please see electrical transmission.
The map below shows which primary energy source different countries get the energy to generate their electricity from. Click on the region to zoom into a group of countries, then click on the country to see where its electricity comes from.