Contracted power in Spain: how many kW your home needs (and how to tell if you overpay)
Contracted power is the fixed cost on your bill: it is charged every day of the month, whether you use electricity or not. It is also where most people overpay without knowing. Here is how to work out how much you really need.
What contracted power actually is
It is the maximum electricity you can use at the same time, measured in kilowatts (kW). It has nothing to do with how much you consume in a month, but with how many appliances you can run at once without the supply tripping.
Think of it as the width of a pipe: the wider it is, the more water passes at once, but you also pay more to have it there, whether you use it or not.
How much a normal home needs
These are the most common reference levels in Spain:
| Home | Typical power |
|---|---|
| Small flat, no large appliances running together | 2.3 – 3.45 kW |
| Average home with an electric hob | 3.45 – 4.6 kW |
| Large house, air conditioning or a powerful hob | 4.6 – 5.75 kW |
| With an electric car or heat pump | Needs a specific study |
Many contracts carry a power level inherited from the previous tenant or owner. If you have never reviewed yours, there is a fair chance you have at least one kilowatt too many.
How to work out yours
Picture the worst moment of the day. For example, a winter evening with the hob on, the oven running, the washing machine going and the lights on. Add up what those appliances draw:
- Electric oven: 1.2 to 2.2 kW
- Hob (one ring): 1 to 2 kW
- Washing machine: 1.5 to 2.2 kW while heating water
- Air conditioning: 0.9 to 2 kW
- Microwave: 0.8 to 1.5 kW
- LED lighting for the whole house: under 0.2 kW
If that peak rarely goes above 3.5 kW, contracting 5.5 kW is throwing money away every day of the year.
What happens if I lower it
If you cut it too fine, the power control switch will trip when you turn on too many things at once. You fix it by resetting the switch and turning something off: there is no damage and no fault, only the nuisance.
That is why it makes sense to leave a reasonable margin rather than adjusting to the exact limit.
How much you save
Every contracted kilowatt you remove is roughly 40 to 50 euros less a year on the power term. Going from 5.5 kW to 4.6 kW in a home that does not need it is around 45 euros a year; dropping two kilowatts, close to ninety.
It is not a fortune, but it is a saving that repeats every year without changing a single habit. For a holiday home that is empty most of the year, it is usually the first thing to check.
A detail almost nobody uses
On the 2.0TD tariff you can contract two different power levels: one for peak hours and one for off-peak. If your heavy use is at night (electric car, storage heaters), you can have a low level by day and a higher one at night, when it is cheaper.
It is legal and available, but few suppliers offer it unless you ask.
Frequently asked questions
How many kW does a normal home need in Spain?
An average home with an electric hob usually works well with between 3.45 and 4.6 kW. Small flats without large appliances running together can go down to 2.3 – 3.45 kW.
How much do you save by lowering your contracted power in Spain?
Each kilowatt less is roughly 40 to 50 euros a year on the power term.
What happens if my contracted power is too low?
The power control switch will trip when you use several large appliances at once. It causes no damage: you reset the switch and turn something off.
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