We use electricity every day — for lights, fans and phones. But electricity must come from somewhere. These starting points are called sources of electrical energy.
Common sources
- Dry cells (batteries): change chemical energy into electricity; used in torches and toys.
- Accumulator: a battery you can charge again, used in cars.
- Solar cell: turns sunlight into electricity.
- Dynamo: a small generator, for example on a bicycle lamp.
- Power stations: make large amounts of electricity for our homes.
Key idea
Renewable energy (Sun, wind, water) will not run out. Non-renewable energy (coal, petroleum, natural gas) will run out one day.
Choosing wisely
Renewable sources are better for the Earth because they do not run out and cause less pollution. Using them helps keep our air clean for the future. Malaysia gets a lot of sunshine, so solar cells are a useful renewable source here. Coal and petroleum are burned in power stations, but they add smoke to the air and cannot be made again quickly.
Remember
- Batteries store chemical energy.
- Solar cells need sunlight.
- Renewable = does not run out.