Power grid · KNOWLEDGE GUIDE
Power charge, kW and kWh - how to avoid mixing them up
The same amount of electricity can be used in different ways. Understand the difference between energy and power before planning charging and heating.
THE MOST IMPORTANT THING IN ONE MINUTE
- kW describes power. kWh describes energy over a period of time.
- Multiple large loads at the same time can produce a higher peak than if they are run one after the other.
- Not everyone has the same tariff, and the previous general introduction requirement of 2027 has been lifted.
Two units, two questions
Kilowatt, kW, helps you answer how big the power is. Kilowatt hour, kWh, describes the amount of energy. For a constant load, energy = power × time applies.
An own unit exercise: 3 kW for two hours becomes 6 kWh. The same 6 kWh can be used with 1 kW for six hours. The amount is the same, but the distribution over time looks different. Real devices may change power during driving.
Source material: Ei: questions and answers about power charges ↗
Why does concurrency matter?
In a simplified example, suppose the load uses 4 kW and another load uses 2 kW. At the same time, the sum is 6 kW. If they can be run one behind the other without changing other conditions, the peak power will be lower.
This does not automatically mean a certain saving on your bill. First, you need to know if the tariff includes an impact charge, which periods are included and how the network company measures or averages the impact.
Source material: Ei: questions and answers about power charges ↗
What rules apply in October 2026?
Ei states that the regulations that required power charges from all grid companies by January 2027 at the latest were repealed in June 2026. It is therefore misleading to say that all households must receive such a charge then.
However, the fee is not prohibited. A grid company can retain or introduce an effect-based model within current regulations. Use your actual contract and current tariff instead of older general texts.
Source material: Ei: power charges - current rules ↗
Ask the network company to show the calculation
Start with a monthly invoice and the price list that applied at the time. Ask the network company to point out which measurement intervals are behind the charged power. Check which days and times count.
Also ask how a short peak affects compared to a more extended load. Once you know that, you can decide if lower charging power, longer charging time or a different order between the loads is relevant.
- What measuring range is used?
- Is it a highest peak or multiple values that count?
- Are there different times, seasons or exceptions in the tariff?
Source material: Energy Market Agency: the electricity grid agreement ↗ · Ei: questions and answers about power charges ↗
Plan for both price and capacity
If all devices start in the same cheap quarter, your simultaneous power may increase. With an impact fee, the lowest spot price is therefore not always the same as the lowest total cost.
Start with a schedule that still works in everyday life. The car must be ready when you need it and the heating must work. Then follow up with the actual metrics. Change one thing at a time so you can see what made a difference.
Source material: Ei: electricity contracts with quarter-hour pricing ↗ · Ei: control the charging of your electric car ↗
Calculate from kW to kWh.
Change the power and time. See that high power and large amount of energy are different things.
Immerse Yourself
FAQ.
Is low consumption always the same as low power?
Nope. A short period of high power can provide little total energy. Your tariff determines how this affects the fee.
Should I always run things at night?
Not as a general rule. Read both the price and your network tariff. In addition, adhere to appliance safety instructions and the needs of the home.
FROM KNOWLEDGE TO EVERYDAY
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Sources and further reading.
The material was checked on 26 October 2026. Follow the links for current terms and conditions.