Potencia contratada is one of the easiest ways to overpay for electricity in Spain. It is the kW capacity you reserve, and it creates a fixed daily cost on your bill.
- Small flats often work around 2.3–3.45 kW.
- A/C homes commonly need 4.6–5.75 kW.
- Villas, EVs and heat pumps may need 6.9–10.35 kW or more.
Use this guide to right-size your Spanish electricity contract before you move in, buy a property, or switch provider.
Too much potencia wastes money every month. Too little potencia trips the power when normal appliances run together.
What potencia contratada means
Potencia contratada is your contracted power. Think of it as the maximum electrical capacity your home can draw before the system cuts out. It is measured in kilowatts, or kW.
It is not the same as how much electricity you use. Consumption is measured in kWh. Potencia is the capacity you reserve. The higher your contracted kW, the more you pay in fixed daily charges.
That makes potencia a right-sizing problem. You want enough headroom for real life, but not so much that you pay for capacity you never use.
Typical potencia bands by home type
These are planning ranges, not engineering advice. The real answer depends on appliances, A/C, heating, water heating, EV charging, pool equipment, and how many things run at once.
| Small flat 1–2 people, gas cooking/hot water, limited A/C | 2.3–3.45 kW |
| Normal apartment 2–3 people, normal appliances, some A/C | 3.45–4.6 kW |
| A/C-heavy home or townhouse Oven, dishwasher, washing machine, multiple A/C units | 4.6–5.75 kW |
| Villa Pool pump, more rooms, garden loads, guest use | 6 kW+ |
| EV, heat pump or all-electric home Large simultaneous loads | 6.9–10.35 kW+ |
The key word is simultaneous. A home can own a lot of appliances and still work on modest potencia if they are not used at the same time. Trouble starts when the oven, induction hob, A/C, washing machine, kettle and water heater overlap.
The rental, second-home and multi-dwelling trap
Expats often inherit the previous owner’s or tenant’s setup. That can be fine, but it can also be wrong for how you use the home.
Rentals may be under-sized because the landlord wanted to keep fixed costs low. That looks cheap until the power trips every time you cook with the A/C running. Second homes may be over-sized because nobody has reviewed the bill for years. Villas can be trickier: a main house plus guest house, pool, outdoor kitchen, or workshop may need more capacity than a normal family home.
The expensive version is upsizing twice. A buyer moves into a villa, increases potencia once, then discovers the guest house or EV charger needs another change. Before changing, list the big loads and where they sit. If there are several dwellings or separate circuits, get proper advice instead of guessing.
How to read your current potencia on a Spanish bill
Look for lines such as potencia contratada, término de potencia, or potencia punta/valle. Some tariffs show two power periods: peak and off-peak. The bill should show the kW you have contracted and the daily price for that capacity.
If you are buying or renting, ask for the latest bill before completion or move-in. It will also show the CUPS number, current supplier, and whether the supply is active. Those details matter if you want to change the name, change provider, or adjust the contract.
How often can you change potencia?
Do not treat potencia like a casual setting you can adjust every week. In Spain, changes are limited and may involve distributor approval, fees, or technical checks. In practice, you should choose carefully and avoid repeated trial-and-error.
Lowering potencia can save money if the home is over-sized. Raising it can solve nuisance trips, but if the increase is large or the installation is old, you may be asked for an electrical certificate. That is another reason to check the property setup before changing.
Get the contract right before comparing providers
Provider comparison only works if the home setup is sane. If your potencia is wrong, even a good tariff can feel expensive or unreliable.
For the wider setup, read our home energy guide for Spain. If you want help right-sizing the electricity setup and comparing options in English, start your energy setup with Settlewell.
FAQ
What potencia should I contract in Spain?
Small flats often work around 2.3–3.45 kW, normal apartments around 3.45–4.6 kW, A/C-heavy homes around 4.6–5.75 kW, and villas or EV homes may need 6.9 kW or more.
What happens if my potencia is too low?
The power can trip when too many appliances run at once. You may need to reduce simultaneous use or increase contracted power.
What happens if my potencia is too high?
You pay more fixed charges every month than you need to. This is common in homes where nobody has reviewed the contract for years.
Can I change potencia after moving in?
Usually yes, but changes are limited and can involve fees or technical checks. Check your bill and property needs before requesting a change.
