GUIDES
What is contracted power (potencia contratada)?
Contracted power is measured in kW and concerns how much electricity your home can demand at the same time, not how much it uses over a month.
Last checked: September 2026
What it means
Contracted power is the level of simultaneous demand your electricity contract is set up to allow. It is measured in kW. Consumption is measured in kWh.
Running an oven, induction hob, washing machine and air conditioning together requires more power than using them one after another. That is called simultaneity.
Why it matters
Too much contracted power can mean paying more fixed cost than you need. Too little can lead to an interruption or limiter activation for many small domestic supplies when simultaneous demand exceeds the contracted level.
Do not choose a number from home size alone. Appliances, heating or cooling, electric-vehicle charging, household habits and what runs at the same time all matter.
What to look at
For supplies at or below 15 kW, the CNMC guide says bills should show maximum demand over the last year for the relevant periods. Distributor customer areas can also provide consumption and maximum-demand information.
Under the domestic 2.0TD structure, applicable power periods can have different contracted values. The maximum admissible power of the installation can also limit what can be contracted; the electrical installation certificate (CIE) is relevant to that limit.
Before changing it
Use your bill and demand data as evidence, then consider your normal simultaneous use. If you are unsure about the installation limit or a technical change, check with the distributor or a qualified installer.
Official sources
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