#### If electricity was water…

An example that is often referred to as the components of current is the following:

Electricity “flows” as well as water. So imagine the current as water. The volt (V) denotes the voltage of the current. The voltage (P measured in volts) is the gradient with which the electrons flow through a cable. This is comparable to the slope of water in a water pipe.

Ampere (A) on the other hand, is the measuring unit for the current intensity. This is comparable with the thickness of the water line: if the line is very thick, much more water can flow than with a thin line. As a result, the water has more power. The amperes and volts are the same as the water pressure and the amount of water flowing through. For example a high pressure cleaner can remove dirt from aluminum rims, because it builds up pressure but it would not be suitable for a larger fire.

Another example to illustrate this is the comparison with a hydroelectric power plant. A hydroelectric plant can produce more power (watts) the more water flows in and the higher the gradient (voltage measured in volts) with which the water hits the turbines. If there are many large stones in the river bed and slow down the flow of water, the power would be correspondingly reduced. The stones correspond to the electrical resistance, measured in ohms (Ω). The total water quantity represents the current measured in amps (I).

The more cross-section the river bed has on the way into the hydroelectric power plant, the more current can flow through this river. A larger cable section also means that the cable can withstand more current and can carry more power. It follows that the power (P) is dependent on the voltage (U) and the current (I). The formula for the calculation of Watts is:

Who does much, consumes also a lot. A hair dryer is with about 1400 watts a real power carrier. But how much does a hair dryer use when it does so much? The consumption of the hair dryer is measured in kilowatt hours (kWh).

The abbreviation kWh sure you know from your electricity bill. To explain what plays into KWh, the individual factors watt, hour and kilo have to be explained. 1400 Watts correspond to the performance of the hair dryer. In order to correctly calculate the consumption, the correct question is: How long does the hair dryer blow? The consumption is always related to a period.

Therefore, the performance is measured with respect to the time (in the case, one hour) for the hair dryer. A watt-hour (Wh) is the consumption that a device with a power of 1 Watt consumes within an hour. In the household, there are only a few devices with only one watt power.

The hair dryer with its 1400 watts consumes in an hour logically 1,4 kWh. The word “kilo” comes from the Greek language and means nothing more than “a thousand”. It is added to not have to call endless high numbers. One kilogram is a thousand grams. And so 1000 watt-hours are 1 kilowatt-hour (1000W = 1kWh).