What is electricity?

Photo: Wikimedia Commons, U.S. Air Force photo by Edward Aspera Jr.

In everyday life we use electricity for a great many things. We can actually not imagine everyday life without electricity, and are absolutely dependent on it. But it has only been in the past 100 years that people have been able to use electricity.

The ancient Greeks knew about electricity. They produced electricity by rubbing a piece of fur against amber. (Amber is resin from fossilised trees.) The word electricity comes from the Greek word elektron, which means amber. Electricity never gained any practical significance for the Greeks, because they did not use it as an energy source.

What electricity actually is became clear after 1900, when scientists had created the atomic model.

All substances are made of atoms. Each atom holds a nucleus with a positive charge. Electrons, which have a negative charge, circle around the nucleus. Electric currents arise when the electrons move.

When the Greeks generated electricity by rubbing fur against amber, the friction freed the electrons. When you comb your hair you can feel the friction between the hairbrush and your hair. This is static electricity.

Electricity did not become of practical use until it was possible to get it to move through cables, around the year 1900. Useful electricity is electrons that is in movement.

In Norway we produce electricity from water that is in movement. When water pours down towards the sea, we use the energy in the mighty waterfalls through the aid of large hydropower works.

You can read more about how we produce electricity from water in the following text.