Electricity is generated when a conductor is moved through a magnetic field.
So if you move a coat hanger between the north and south poles of a magnet, a Voltage will be generated in the coat hanger.
We like to think of electricity like water in a pipe as you can see and understand water. Electrons on the other hand are very small.
Electrical current is like the flow of water in a pipe. The more current you have in an electrical wire, the bigger the wire needs to be to carry the current. This is just the same as a water pipe. The more the volume of water you want to pass through a pipe, the bigger the pipe needs to be.
Increasing the size of the pipe is equivalent to the electrical resistance of an electrical cable.
Another way to increase the current flow in the electrical wire is to increase the Voltage. Voltage is like pressure in a pipe. Voltage is needed to push electrons through an electrical circuit. You can either shove more water through a pipe by increasing the size of the pipe (reducing the resistance) or increasing the pressure of the water (increasing the Voltage).
A rain water tank is like a battery. It is a reservoir of water that is stored there for 24-hour consumption. A battery is a reservoir of electricity. It provides a buffer so energy can be drawn down from the battery as needed. This is similar to a battery in a mobile phone. A phone battery is constantly being charged and discharged as the battery provides an element of storage of electricity meaning you don’t always need to be connected to a power plug.
The Power Equation
Electrical power is measured in Watts and is the product of Voltage and Current:
Power (Watt) = Volts x Current (Amp)
This is also the same for water:
Power (Watt) = Pressure of Water x Volume of Water.
If you take a hose and point it at a water wheel, you can increase the power generated by either turning up the hose to the maximum so more water comes out and hits the wheel, or you can increase the pressure coming out of the hose.