• Question: Where does electricity come from?

    Asked by back1pac to Jamie on 14 Mar 2024.
    • Photo: Jamie Smith

      Jamie Smith answered on 14 Mar 2024: last edited 14 Mar 2024 9:43 am

      Electricity is caused by the flow of electrons or other charged particles. Electrons are part of atoms, the float around the atoms main body (nucleus). They have a negative charge, so will move towards bodies that are positively charged (kind of like a magnet). We can cause the flow of electrons by applying a voltage, which is like a force on charged particles. We call the size of the flow a current, measured in Amps. So electricity comes from systems which are capable of applying this force on the electrons.

      One method is chemically, when certain materials are joined together in an acid, the charges in those materials push against each other and move to try and balance out. This is what batteries are.

      Another is by using magnets. Mangetic and electric fields are very closely linked, and if something moves through a magnetic field, the electrons in that thing will have a voltage applied to them (if the movement is at a 90 angle to the field). This is what happens in wind turbines or steam generators, we use wind or pressure to move coils of metal through a magnetic field, and this causes the electric current. As it happens, motors do this in reverse. They use electricity flowing through a magnetic field to cause movement.

      The other commonly used method is by the photoelectric effect (light +electricity). In some materials, electrons are released when hit by by light. This can cause them to become free. By carefully combining materials, you can create a system that uses this to send electrons all the way round a circuit after they are released by light. This is how solar panels work