Choosing your contracted power (potencia) in kW

Terms used

• ICP — The ICP is a power-limiting switch that cuts the supply when you use more than your contracted power.
• Maxímetro — The maxímetro is a meter that records your maximum power demand, used on supplies above 15 kW.
• 2.0TD — The 2.0TD is the electricity tariff for homes and small supplies up to 15 kW.
• 3.0TD — The 3.0TD is the electricity tariff for supplies above 15 kW.
• Boletín — The boletín (also called CIE) is an electrical certificate issued by an installer for your installation.

Key rules

• Raising power: Raising your power normally costs regulated charges, while lowering it is usually free.
• Peak versus off-peak: P1 (peak) kW costs much more than P2 (off-peak) kW.
• After a change: The distributor can refuse another change for 12 months, except increases.
• 15 kW limit: Above 15 kW you move to a different tariff with a maximum-demand meter.

Charges and per-kW prices change, so confirm current figures and change limits with your supplier and distributor before acting.

What to choose

Pick the lowest kW that covers the appliances you run at the same time. Too low and the power trips. Too high and you pay for unused kW every month, because the fixed part of your bill is your contracted kW multiplied by a price per kW.

Homes can contract in 0.1 kW steps. Common standard levels are 3.45, 4.6, 5.75, 6.9, 8.05, 9.2, 10.35, 11.5 and 14.49 kW. Which levels are open to you depends on your supply and installation.

How to size it

Add up what could run together at peak: oven, induction hob, washing machine, water heater, air conditioning, car charger. Heavy electric use (electric heating, induction, a car charger) usually pushes you towards 5.75 kW or more. If you cook and heat with gas and have few big appliances, a lower level is often enough. If the power trips more than once in a while, raise it. If you never come close, lower it.

Two price periods

Since 2021 the fixed charge has two periods: P1 (peak hours) and P2 (off-peak). P1 costs much more per kW than P2. You usually have the same kW in both, but you can choose different values. Compare the price per kW for both before deciding. The regulated part of the price is set by the State and revised yearly. Your supplier cannot change it, but it can add a margin.

How to change it

Ask your supplier. It passes the request to the distributor, the company that carries out the change. You can raise or lower your power at any time, to any standard level up to 15 kW. You cannot go below what your installation needs or above what it allows.

• Raising power: normally means regulated access charges, and sometimes extension charges. Amounts are set per kW and can change, so ask your distributor and supplier for the current figure before you agree.
• Lowering power: is usually free. But after a change the distributor can refuse another change for 12 months, except increases. A reduction followed by a later increase may mean paying access charges again. Don't cut too far.
• Supplier fee: some suppliers add their own admin fee, though many charge nothing.
• Certificate: if the distributor says your installation needs a new electrical certificate (boletín or CIE), an installer charges for it separately.

The timeline, documents and checklist below cover the steps.

Up to 15 kW and above

Up to 15 kW your home is on the 2.0TD tariff. At 15 kW or below, an ICP (a power-limiting switch) controls the limit. Above 15 kW you move to the 3.0TD tariff, which needs a maxímetro that records your maximum demand. Check with your supplier before going that way.

Timeline and deadlines

• Ask your supplier to change your contracted power: at any time

Documents you need

• A new electrical certificate (boletín or CIE), issued by an installer, only if the distributor says your installation needs one for the change. The installer charges separately.

Checklist

• Ask your supplier to pass the power change to the distributor, the company that carries it out.

• Ask your distributor and supplier for the current fees before you raise your power.

• Check whether your supplier adds its own fee for processing the change.

• Ask whether another change in the next 12 months would be refused before you lower your power.

• Ask whether you need a new electrical certificate, which an installer charges separately.

Frequently asked questions

Can I lower my contracted power and raise it again later?

Yes, you can lower your contracted power freely, but raising it again later may mean paying access fees again. Lowering is usually free in itself. Think about your real peak use before cutting, so you do not pay twice.

Can I choose a different kW for peak and off-peak periods?

Yes, you can choose different kW values for P1 (peak) and P2 (off-peak), although one value is usually the same in both on the 2.0TD tariff. P1 costs much more per kW than P2, so a lower P1 value can cut the fixed charge.

Can my supplier change the price per kW in the fixed charge?

No, your supplier cannot change the regulated part of the fixed charge, though it can add its own margin. The regulated price per kW is revised yearly, so the fixed charge can change even if your kW stays the same.