How much does it cost to use air conditioning?

Rising temperatures mean that many people are turning to air conditioning more, but using air conditioning will represent an increase in energy bills at the end of the month. But what are the costs?

"Regular use can represent a significant burden on the electricity bill, in some cases representing up to 15% of the total monthly amount", notes Selectra, in a statement sent to Notícias ao Minuto.

The tariff comparison company explains that the "cost of air conditioning essentially depends on the power, the time of daily use, the type of technology (inverter or conventional) and the price per kWh".

"Other factors include the thermal capacity (BTUs), the energy class and the type of appliance - portable (less efficient), split (for one room) or multisplit (several rooms)".

Selectra's calculations - taking as a reference a device with a power of 2,500 W (2.5 kW) - reveal that the monthly cost can "vary considerably, depending on the time of use":

The formula for calculating monthly consumption is as follows: Monthly consumption (kWh) = Power (kW) × Hours of use/day × 30 days. Monthly cost (€) = Monthly consumption × Price per kWh (check your electricity bill)

For example, for a 2.5 kW device operating 8 hours a day:

2.5 kW × 8 h × 30 days = 600 kWh

600 kWh × €0.1595 = €95.70

To this amount must also be added the applicable taxes and fees, namely:

Special Electricity Consumption Tax (IEC) – €0.001/kWh;

Operating fee of the Directorate-General for Energy and Geology (DGEG) €0.07;

Audiovisual Contribution (CAV) – €3.021

The formula assumes a worst-case scenario. Aircons will ramp down the power once they reach the set temperature. They often average 30–60% of their max power in steady-state operation.

By Edward from Porto on 22 Jun 2025, 11:46

Maybe these prats should think about the cost to the environment..

By Adam from Porto on 23 Jun 2025, 05:51

Here is a perfect exaple of journalists spreading useless information because they do not understand how things work but yet they keep on misinforming their readers. A 2,5kW air conditioning unit does not consume 2.5kW every second. Of course it depends on outside temperatures and what temperature you wish to cool the room to but it almost never will consume 2.5kW/second. I refer to seconds because your energy consumption is measured per second and then the hourly consumption is totalised from this measurement. My 2kW aircon cools a 16m2 room to 24 degrees with a consumption rate of 300 watts/second which would be 0.3kW/hours for which I pay during the day 7 cents/hour. Please can journalists stop publishing articles that are false and misleading, it only confuses the readers and makes you look extremely foolish

By Paul from Porto on 23 Jun 2025, 15:53

Typical, Europeans always only see the costs, but don't consider the economic benefit of having air condition and being able to think clearly in summer...

By Vincent from Lisbon on 24 Jun 2025, 07:53