How Much Contracted Power Do You Really Need for Your Home in Spain?

When you receive an electricity bill in Spain, you pay for more than the electricity you actually use. Part of your bill depends on your contracted power, known in Spanish as potencia contratada.

This figure determines how much electrical power your home can normally draw from the grid at the same time. If it is higher than necessary, you may be paying for capacity you rarely use. If it is too low, you could experience interruptions when several appliances operate simultaneously.

But how much contracted power do you really need for your home in Spain? The answer depends less on the size of your property than on your appliances, your daily routines and the amount of electricity you need at any given moment.

In this guide, we explain how to estimate your household’s power requirements, what to check before changing your contract and how to find a suitable balance between electricity costs and everyday comfort.

 

What does contracted power mean in Spain?

 

Contracted power is the maximum electrical power, expressed in kilowatts (kW), that you agree to have available under your electricity supply contract. It is different from electricity consumption, which is measured in kilowatt-hours (kWh).

For example, a 2 kW electric heater operating for three hours uses 6 kWh of electricity. The 2 kW figure describes the heater’s power demand, while the 6 kWh figure describes the energy consumed over time.

This distinction matters because the amount of electricity you use over a month does not, by itself, determine how much contracted power your home needs.

Two households could consume a similar number of kWh but require different contracted power levels. One might use electricity gradually throughout the day, while another regularly operates several high-powered appliances at once.

In most ordinary residential supplies, contracted power also affects a fixed component of the electricity bill. You pay for this capacity even when your electricity consumption is low.

That is why reviewing your contracted power can be worthwhile, particularly if the figure has remained unchanged for several years.

 

How many kW of contracted power does a typical home need?

 

There is no single contracted power level that is suitable for every home in Spain. As a starting point, households can consider broad illustrative ranges based on their appliances and typical simultaneous use.

 

Type of household	Illustrative power range
Small apartment with limited electric appliances	2.3–3.45 kW
Apartment with an electric oven, washing machine and other common appliances	3.45–4.6 kW
Family home with several high-powered appliances	4.6–5.75 kW
Home with substantial electric heating, cooling or other major loads	5.75 kW or more

 

These are examples for initial assessment, not official recommendations or guaranteed minimum requirements.

A small apartment with electric heating and a powerful induction hob may need more contracted power than a larger home with gas heating. Similarly, a detached property with efficient equipment and carefully managed electricity use may operate comfortably with less power than expected.

The most reliable way to determine an appropriate level is to review the home’s actual maximum demand and consider which appliances need to operate together.

 

How to calculate the contracted power your home needs

 

You can make an initial estimate of your electricity requirements without being an electrical expert. The objective is to identify how much power your household might need simultaneously, rather than adding together every electrical appliance you own.

Step 1: Identify your highest-powered appliances

Start with appliances that typically require substantial electrical power. These may include an electric oven, induction hob, electric water heater, washing machine, tumble dryer, air-conditioning system or electric vehicle charger.

You can usually find their rated power in the manufacturer’s documentation or on the appliance label. For an initial calculation, the following figures illustrate possible appliance power ratings:

 

Appliance	Example power rating
Electric oven	2,000 W
Induction cooking zone	1,800 W
Washing machine during water heating	2,000 W
Electric water heater	1,500 W
Microwave	1,000 W
Television	100 W

 

Actual ratings vary by model, and many appliances do not operate continuously at their maximum rated power. For that reason, these figures should only be used to understand the calculation.

You can read our article on what to look out for before buying a new household appliance.

Step 2: Consider which appliances run at the same time

Next, think about how your household normally uses electricity. Imagine that you are preparing dinner while the washing machine is operating. Your home might simultaneously use:

• Electric oven: 2,000 W
• Washing machine during heating: 2,000 W
• Television: 100 W
• Lighting and other small loads: 200 W

The combined demand in this hypothetical example would be: 2,000 + 2,000 + 100 + 200 = 4,300 W. That is equivalent to 4.3 kW.

This does not mean that the household must automatically contract exactly 4.3 kW. Appliances may cycle on and off, actual demand may be lower than rated power, and the electricity meter’s power-control behaviour also matters.

However, the example demonstrates why simultaneous use is more important than simply counting the number of appliances in a home.

Which home appliances consume more electricity? Find out with us.

Step 3: Check your actual maximum power demand

An estimate is useful, but real consumption data provides a stronger basis for making decisions. In Spain, households with smart meters can generally access information about their electricity consumption and maximum recorded power through their electricity distributor’s customer portal.

The CNMC recommends consulting this information when assessing whether contracted power is appropriate. Ideally, review a full year of data.

This helps account for seasonal differences, such as increased air-conditioning use during summer or electric heating during winter.

It is also worth checking whether any unusually high readings correspond to circumstances that are unlikely to happen again.

Step 4: Allow for your household’s practical needs

The final decision should consider more than the highest number recorded. For example, if you regularly cook while running other appliances, you may prefer sufficient contracted power to avoid having to change your routine.

Alternatively, if certain appliances can easily be used at different times, you might be comfortable with a lower level.

The aim is not to contract the smallest possible number of kilowatts. It is to choose a level that matches your real electricity requirements without paying unnecessarily for unused capacity.

 

Why Spain has two contracted power periods for households

 

Most ordinary residential electricity supplies in Spain fall under the 2.0TD access tariff, which applies to low-voltage supplies with contracted power of up to 15 kW in each period. This structure includes two contracted power periods:

• Peak power period (punta): Monday to Friday, from 08:00 to 24:00.
• Off-peak power period (valle): Monday to Friday, from 00:00 to 08:00, plus Saturdays, Sundays and the applicable national public holidays.

These periods follow the regulated time structure, although the price charged for power depends on the electricity contract.

A household can contract different power levels for the two periods. For example, someone who regularly charges an electric vehicle overnight may want to assess whether a higher off-peak power level is useful. Meanwhile, a household with limited daytime electrical demand might be able to operate with a lower peak power level.

However, this does not mean that the off-peak period is always cheaper under every retail contract. It is important to review the prices and conditions offered by your supplier.

Also, the two power periods should not be confused with the three regulated energy-consumption periods.

If you want to understand how electricity prices vary by time of day, our guide to peak and off-peak electricity hours in Spain explores that subject separately.

 

How can you tell if your contracted power is too high?

 

A common sign of excessive contracted power is a substantial difference between your contracted kW and your maximum recorded demand.

For example, imagine a household that has 5.75 kW contracted but rarely demands more than 3.2 kW. That difference may suggest an opportunity to reduce the fixed power component of the bill.

However, the decision should not be based on a single month. It is important to consider periods of unusually high demand, particularly during seasonal changes.

For instance, a home on the Costa Blanca might use relatively little electricity during spring but experience greater demand when air conditioning operates in summer. 

A property in northern Spain may instead have higher winter requirements. If the maximum demand remains consistently below the contracted level across different seasons, a reduction may be worth assessing.

According to the CNMC’s 2024 analysis of household data, many Spanish households had more power contracted than they used. This reinforces the value of checking actual demand rather than assuming that an existing contract is correctly sized.

 

What happens if you contract too little power?

 

Reducing contracted power can lower fixed electricity costs, but setting it too low can cause inconvenience. For ordinary residential supplies using power-control equipment, excessive simultaneous demand may cause the supply to disconnect.

For example, operating an electric oven, an induction hob and another high-powered appliance at the same time could exceed the contracted level.

This is different from the excess-power billing arrangements used in certain other types of electricity supply. In a typical household, the main practical risk of contracting insufficient power is therefore losing electricity temporarily when demand becomes too high.

If this happens repeatedly, it may indicate that your contracted power is insufficient for your normal activities.

However, repeated interruptions can also have other electrical causes. A fault in an appliance or the electrical installation should not be assumed to be a contracted power problem.

If you are unsure why the supply is disconnecting, seek advice from a qualified professional.

 

How much money could you save by reducing contracted power?

 

The potential saving depends on how many kilowatts you reduce and the price your electricity contract charges for each power period.

For example, imagine that your supplier charges an illustrative power price of €30 per kW per year for a particular period.

If you reduce the contracted power in that period by 1 kW, the annual saving on that power component would be: 1 kW × €30/kW/year = €30 per year. This is a simplified example, not a current market quotation.

Actual savings depend on the contracted prices, the periods affected, applicable taxes and any costs associated with changing the contract. If you reduce power in both periods, you would need to calculate the effect separately for each one.

It is also important to remember that reducing contracted power does not automatically reduce the amount of electricity consumed.

If your household continues using the same appliances for the same amount of time, its energy consumption in kWh may remain similar.

The main financial benefit comes from reducing the cost of having electrical capacity available. For a broader explanation of electricity bill components, see our guide to how to understand your electricity bill in Spain.

 

How to change your contracted power in Spain

 

Once you have assessed your requirements, you can request a change through your electricity supplier. The supplier coordinates the relevant procedure with the electricity distributor.

Before submitting a request, check your current contracted power for both periods and decide which values you want to change. It is also worth asking whether the modification will involve any charges or technical requirements.

According to the CNMC, consumers can generally change their contracted power every twelve months, although specific circumstances and exceptions may apply.

This is another reason to avoid making a reduction based on incomplete information. Increasing contracted power can also involve regulated charges and, depending on the installation, additional technical requirements.

After the change has been processed, check your next electricity bill to confirm that the requested values have been applied correctly.

 

Contracted power for holiday homes and second residences in Spain

 

Second homes present an interesting situation because electricity use may vary considerably throughout the year. A holiday apartment might remain empty for several months but experience substantial electricity demand when occupied.

This means that low annual electricity consumption does not necessarily indicate that very little contracted power is needed. For example, a holiday home may consume few kWh during winter but require enough power to operate air conditioning, cooking appliances and a water heater during summer visits.

The correct power level should reflect the property’s actual requirements when it is in use. Reducing contracted power too aggressively simply because a property is unoccupied for long periods may create problems during holidays.

It is also worth considering whether the home is rented to guests. In that situation, the owner may have less control over which appliances operate simultaneously.

For properties used seasonally, reviewing the maximum demand recorded during occupied periods is especially important.

The objective is to avoid paying for excessive capacity throughout the year while ensuring that the property remains practical and comfortable when occupied.

 

Should you review contracted power when installing new electrical equipment?

 

Yes. Changes to a home’s electrical equipment can affect the amount of power it needs.

For example, replacing a gas cooker with an electric induction hob may increase electrical demand during meal preparation.

Installing an electric vehicle charger can also introduce a substantial additional load. Similarly, switching to an electric heating system may change when and how much power your home requires.

However, the effect depends on the specific equipment. Some systems include controls that limit their electrical demand or coordinate operation with other household appliances.

For this reason, you should not assume that every new electric appliance requires an immediate increase in contracted power.

Instead, assess its rated demand, expected operating schedule and compatibility with the existing installation. A qualified installer can help determine whether the new equipment requires changes to your electrical installation or supply capacity.

 

Frequently Asked Questions About Contracted Power 

 

Can you have different contracted power levels for daytime and night-time use?

Yes. Under the 2.0TD structure, households can contract different power levels for the regulated peak and off-peak periods. The appropriate configuration depends on when the property needs electrical capacity and the prices established in the supply contract.

Does having solar panels mean you can reduce contracted power?

Not necessarily. Solar panels may reduce the amount of electricity purchased from the grid when they are generating, but the household may still need sufficient grid power at night or during periods of low generation. Any reduction should be based on the installation’s actual operating conditions.

Can an electric vehicle charger automatically limit its power consumption?

Some charging systems offer dynamic load management, allowing charging power to be adjusted according to other electrical demand in the property. This feature depends on the charger and installation configuration, so it should be confirmed with the installer.

Is contracted power the same as the maximum capacity of your electrical installation?

No. Contracted power is a contractual supply parameter, while the installation’s technical capacity depends on its design, protection devices and certification. A requested increase must be compatible with the electrical installation and the applicable supply conditions.

Do you need to change contracted power when switching electricity suppliers?

Not usually. Changing electricity supplier does not automatically require changing the contracted power. However, you should check that the new contract reflects the intended power levels and understand the prices applied to each period.

Can a landlord or tenant request a contracted power change?

The procedure depends on who holds the electricity supply contract and the terms of the rental arrangement. The contract holder can normally request changes through the supplier, but technical modifications or contractual obligations may require coordination with the property owner.

 

Conclusion: choose contracted power based on how your home uses electricity

 

Understanding how much contracted power your home needs in Spain can help you avoid paying for unnecessary electrical capacity.

However, the correct figure is not determined by the size of your property or the number of people living there alone. It depends on the appliances you use, how often they operate together and the maximum electrical demand your household reaches.

Reviewing your smart meter data, comparing the two contracted power periods and considering seasonal needs can help you make a more informed decision.

A suitable power level should provide enough capacity for normal household activities without creating unnecessary fixed costs.

At Evergreen Eléctrica, we help households in Spain understand their electricity supply and make informed decisions about their energy needs.

Whether you live permanently in Spain or own a holiday property, reviewing your contracted power is a practical way to check whether your electricity contract still suits your home.