What is kWh?

01kWh meaning

A kWh, in full kilowatt hour, is equal to 1000 Wh (watt hours). A watt hour in turn is equal to using 1 watt for 1 hour. So a kWh means: the consumption of 1000 watts for one hour. The abbreviation kWh is made up as follows:

k: kilo, SI prefix for a factor of 1000. Also used, for example, in kilogram (1000 grams) and in kilometre (1000 metres).

W: watt, the physical unit of power (energy per unit of time), named after James Watt.

h: hour, from the English hour.

Calculating kWh

Almost every appliance you can buy states how many watts the appliance uses. If, for example, you use a vacuum cleaner with a power of 1000 W for one hour, you have used exactly 1 kWh. Do you use a vacuum cleaner with a power of 2000 W for half an hour? Then you have also used 1 kWh.

In other words, if you know the power of an appliance and know how long the appliance is used, you can calculate the consumption in kWh yourself. If you then also know how much you pay per kWh, you also know how much you have to pay per day, per week or per year to use the appliance. Bear in mind that many appliances show the maximum consumption. However, that does not mean that this appliance actually uses this continuously. By using the appliance on a lower setting or putting less load on it, the actual consumption can be lower.

What is a watt?

The watt is the unit of power, with the symbol W. It is a derived unit: it is equal to the number of joules (J) per second. The joule in turn is a unit that indicates how much energy is needed to move a body with a force of one newton over a distance of one metre. This means that an appliance with a power of 1 watt uses one joule of electrical energy in one second. As an indication: the energy needed to lift an apple one metre on earth amounts to 1 joule.

Other abbreviations with watt

The kWh is a non-SI unit derived directly from the watt. However, it is not the only derivative of the watt. Other derivatives are:

Wh: watt hour, use of 1 watt for one hour

­mWh: milliwatt hour, one thousandth of a watt hour. Mainly used in electronics applications

MWh: megawatt hour, 1 million watt hours. Used, among other things, to express the power of wind turbines

GWh: gigawatt hour, 1 billion watt hours. Used, among other things, to express the power of nuclear power stations

TWh: terawatt hour, 1 trillion watt hours. Used, among other things, to express the electricity consumption of countries

mW: milliwatt, one thousandth of a watt

kW: 1000 watts

MW: 1 million watts

Many abbreviations are used on the energy market. It is characteristic of the market and it sometimes makes it very complex. Besides abbreviations such as watt (W) and kilowatt hour (kWh), there are quite a few other abbreviations that can cause confusion.

Meaning of abbreviations on the energy market

02kWh on the energy bill

One kWh is equal to 3,6 million joules. In other words, it is rather complex to express consumption in joules on the energy bill. It is simpler to do this in kWh. Based on consumption in kWh, the energy supplier will calculate how much you have to pay. What does 1 kWh cost? That differs per energy supplier and over time. The type of energy contract, the term of the contract and any deals can also influence the price. Moreover, it is not only about the costs of the electricity itself. In practice, the price of a kWh will consist of the following components:

The price of the electricity

Government levies

VAT

Grid operator charges

In other words, it is difficult to say what the price for 1 kWh is. Ask your energy supplier for exact prices.

Tax must also be paid per kWh. In the table below you can read the rates per year.

Source: Belastingdienst.nl

Saving on the energy bill

Let it be clear that saving on the energy bill can only be done in two ways: choosing a cheaper energy contract or using less energy. For the first option, you mainly need to compare energy contracts. Also take the energy deals into account. You can save energy in various ways. For example, by choosing a more energy-efficient appliance, by switching to energy-efficient heating or by insulating your home.

Check out the 125 tips to save kWhs

Generating kWhs yourself with your own solar panels

Dutch households do not only use energy, sometimes they also generate energy themselves by means of solar panels. In the Netherlands, solar panels mainly generate kWhs during the summer months, while kWhs are mainly drawn from the grid in the winter months. In 2004, the net metering scheme was introduced to encourage investment in solar panels. This means that all generated kWhs and the kWhs drawn from the grid were offset against each other. Anyone who generated 2500 kWh and used 3500 kWh therefore only had to pay for 1000 kWh. This net metering scheme has since been adjusted countless times. From 2023, the net metering scheme is in principle being phased out.

More information about solar panels

Meaning of kWh (kilowatt hour)? What does it cost? 1 kWh is how many watts?

The abbreviation kWh appears on the energy bill, among other places. EnergieAanbieding.nl explains what it means and what you can do with a kWh.

03Frequently asked questions about watts and kilowatt hours

Many people mainly know abbreviations such as kWh from their energy invoice. They do not always know what the meaning of such abbreviations is. The energy invoice does not explain it either. The list of frequently asked questions about watts and kilowatt hours below may provide an answer to your questions.

An electrical appliance always states how much energy the appliance uses. This is usually indicated in watts (W) and sometimes in kW (kilowatt or 1000 W). An LED lamp uses 5 W, for example, while a heater uses 1800 W, for example. By multiplying this value by the duration of use, expressed in hours, you know what you can do with a kWh. With one kWh, for example, you can keep the 5 W LED lamp on for 200 hours. You can use the radiant heater mentioned for just over half an hour.