How to calculate power consumption

For electricity, you need to pay, as well as for any other resources and services. In order not to let yourself be deceived when paying, you need to learn how to calculate its expense. There are special devices for this, for example, an individual meter, which is installed in each house or apartment. However, it shows the total consumption, and how to calculate the electricity consumption by a separate device we will describe in this article.

Power, voltage and current

The main characteristics of electrical appliances are voltage, current and power. At the same time, either all three parameters can be indicated on the case or in the instrument passport, or in a selective manner. In Russia and neighboring countries, electrical appliances are used that are designed for a voltage of 220 V AC, in America, for comparison, there may be a voltage of 110 or 120 V.

Recall:

Current is measured in Amperes (A), voltage in Volts (V), and power in Watts (W) (see - How many amperes are in amperes, how to convert amperes into watts and kilowatts) If the appliance is low-power - most likely the power will be indicated in watts, for powerful consumers, such as a washing machine or a kitchen electric stove, they are usually indicated in kilowatts (kW). 1kW = 1000W.

In the passport of the device, depending on the particular case, the power may not be explicitly indicated at all, but rather the electricity consumption for a certain period, for example, kW per year or per day or for another period of time.

So, you pay electricity bills according to the consumed kW / h. Let's take a closer look at what a kilowatt watch is and how to calculate it.

Electric meter

Now every apartment has a power meter or, in simple words, an electric meter. On modern models, there is a display on which the number of kW / h that you have consumed since its installation is indicated.

On older models, this is indicated on a mechanical display indicator of rotating drums with numbers printed on them.

You can find out electricity consumption using a meterIf you turn off all consumers and leave the one that interests you, for example, for 1 hour, then you can find out how much W / h or kW / h it consumes. But such a method is not always convenient and possible.

Note:

On most counters, the rightmost digit is usually either separated by a comma, or highlighted in a different color, or indicated in a different way. This is a tenth of a kilowatt; it is not taken into account when taking readings for payment.

It is also worth noting that not all electrical equipment consumes the power indicated in the documentation during the entire time of operation. This is due to the mode of operation. For example, a washing machine consumes current depending on whether the heating is turned on, whether the pump is operating, at what speed the engine rotates, and so on.

A little later we will consider a simple way to determine the actual consumption of such equipment.

Power Consumption

If you know the electric power of the device, then to calculate the electricity consumption, you need to multiply the power by the number of hours. Let's give an example, let's say we have 2 bulbs - 100 and 60 W and an electric kettle with a power of 2.1 kW. On the day, the light bulbs shine for about 6 hours, and the teapot boils for 5 minutes, you drink tea 4 times a day, which means it only works 20 minutes a day.

We calculate the energy consumption of all this equipment.

Two light bulbs:

100W * 6h = 600W / h

60W * 6h = 360W / h

The electric kettle works 20 minutes a day, since we need to translate into hours, then this is 1/3 of the hour, then:

2100W * (1/3) h = 700W / h

Total:

600 + 360 + 700 = 1660W / h

Convert in kW / h:

1660/1000 = 1.66kW / h

This set of electrical equipment consumes 1.66 kWh per day.

Now you can calculate how much money you spend on his work per day, week, month. To do this, multiply by the tariff, for example 4 rubles per 1 kW / h

Total cost of operation of the listed equipment is equal to:

1.66 * 4 = 6.64 rubles

How to convert amperes to kilowatts?

In cases where only the voltage and current of the type are indicated in the data on the parameters of the electrical appliance:

220V 1A

It is necessary to calculate the power before calculating the consumption, for this we use the formula: P = U * I

For instance:

220V * 1A = 220W

If you do not go into details, this is true for a load with cos рав equal to one, in fact, for most of household electrical equipment. Further calculations are similar to the previous ones.

How to find out the actual energy consumption of the device?

Calculations will not show real values, to find out, you just need to make measurements. The surest way is to use an electricity meter. The most convenient option is to use a special meter for the outlet.

They are also called an energy meter or wattmeter, perhaps this will help you find the device on sale.

What can an energy meter do? This is a universal measuring device with the following set of functions:

• Measurement of current power consumption.

• Measurement of consumption over a period of time.

• Measurement of current and voltage.

• Calculation of expenses at the rates you set.

That is, you just need to insert it into the outlet, and the device, the consumption of which you need to determine simply, plug into the outlet located on the energy meter. After that, you can observe how the power consumption changes during operation and how much is consumed in one working cycle.

An example of using a socket meter to determine the power consumption of a refrigerator is shown in the video.

Conclusion

Calculation of energy consumption may be needed in a number of situations, for example, to check the consumption of new equipment, or when sharing powerful consumers with neighbors for equal pay. The best way is to install an individual meter on the device or its outlet version, as described above.