Electricity has a lot in common with cars racing on a track. To have a race, you need a clear road with a good surface. Like the flick of a switch, as soon as the flag is dropped the cars have an open path, allowing them to speed towards the finishing line. Once all the cars have reached the end, the race is over.

Electricity is like a race, where every car is an electron, moving down a conductor like it’s a racetrack. Once they reach the end, the race is over, and the flow of electricity stops. To keep electricity flowing, conductors are arranged as a loop called a circuit, where a steady supply of electrons can keep on racing.

At the flick of a switch, the electrons are sent through the circuit in a race we call a current of charge. They race from the negative end to the positive end of the circuit. This is how electricity moves through the circuits in our homes, vehicles, and devices.

These racing electrons, generating electricity, can be started in many ways. Sometimes fossil fuels are burned to make steam that pushes huge magnets, which in turn makes electrons move back and forth. Other ways rely on natural resources like the wind to push the magnets, or sunlight to get electrons racing inside special solar cells. No matter the source, electrons race along long circuits we call a power grid, like traffic on a highway, to carry power to our homes and schools.

But what happens when the sun stops shining, or the wind stops blowing? Unfortunately, the electrons stop racing. Luckily there’s a way to store electricity so we can still power everything we need, even on a still, cloudy day. Another example of a racetrack for electrons is called a cell, though you may know it as a battery. It uses a combination of materials to create a chemical reaction to start the electrons racing, generating electricity. This is called an electrochemical cell, or of course a battery.

There’s a wide variety of batteries for a range of needs, storing electricity, waiting to be connected to a circuit. Some are tiny, packed up tight into discs or small cylinders. Some contain special materials that give electrons a huge push, giving the battery a big electric output. By connecting a big battery with another power source, such as a wind turbine or solar farm, big batteries can store renewable energy and only release it when it’s needed most.

So when the sun is shining, and the wind is blowing, electricity can be stored in large batteries, holding electrons at the starting line, ready to race another day.