La potència és el màxim d’electricitat que es pot consumir en un mateix moment. Ajustar la potència elèctrica contractada a les vostres necessitats i evitar contractar kW de més repercutirà positivament en la factura de la llum. Pot tractar-se d’un estalvi petit si baixeu un o dos esglaons de potència, o de més si aquesta baixada suposa un canvi de tarifa elèctrica a una inferior de la que teníeu.
What is electrical power?
According to the Institut Català de l’Energia (ICAEN), the electrical power supply you need depends on two factors: the type and number of electrical appliances you have and the energy needed to run these appliances.
If your electricity still hasn’t been connected and you want a connection, first look at your electrical installation certificate. This document guarantees the quality and working order of your electrical installation and indicates if you have a single-phase power installation (usually for domestic installations), or a three-phase installation. The electrical installation certificate also gives the recommended electrical power supply and the maximum power to install. The maximum power supply cannot be exceeded, as your installation will overload. You can also change the recommended power supply if you think it is too high.
Change your maximum import capacity
If you want to change your maximum import capacity, you should contact your electricity company and request a reduction in your import capacity. This has an associated cost of €10,94 (VAT included). Remember that you can only make one change per year to your maximum import capacity.
If your contracted power supply is under 15kW, and you want to see if you can lower it or maintain it, there are three ways of finding out:
The exact method. Smart meters, made by several manufacturers, can now be installed and will indicate the maximum power supply you need. When you have installed a smart meter, measure your electricity consumption for a few days. The meter will indicate the maximum consumption during this period and this value will be the minimum electrical power supply that should be installed. It is recommendable to request a power supply that gives a small margin over that given by the meter to avoid any problems.
The trial and error method: the Power Control Switch (PCS). The PCS is the safety switch installed in the electricity meter that disconnects the electricity if you need a bigger power supply than you have contracted. If your PCS has never tripped, this may mean that you have more power contracted than you need. To do the test, connect all your electrical appliances at the same time (lights, oven, vitroceramic cookware, dishwasher, washing machine, dryer, iron, microwave, air conditioning...). If the PCS doesn’t trip, this means you have a margin for reducing power.
The PCS measures electricity in amps. This value converted to kW must coincide with the power supply contracted.
Estimated method: Another way to estimate how much power you need is to add up the power (kW) of all the electrical appliances. To this figure, add a margin of 1kW for lighting and small electrical appliances. Now divide the number by 3, as not all electrical appliances are usually used at the same time. Take into account that the resulting value must always be higher than that of the electrical appliance that consumes the most power. The result of the division will help you to choose the right power supply.
If the electrical installation is prior to 2006 you will probably have 3.3kW, 4.4kW, 5.5kW, 6.6kW, 7.7kW, 8.8kW or 9.9kW. When you change (if it is single-phase), you will have to choose between the following: 1.15kW, 2.3kW, 3.45kW, 4.6kW, 5.75kW, 6.9kW, 8.05kW, 9.2kW, 10.35kW, 11.50kW and 14.49kW.
Any of these methods will give you an idea of the amount of power you need. Take into account that you can only change your maximum import capacity once a year and so be careful when reducing the amount of power you have contracted, because if you lower it too much you might overload the system and the PCS will be constantly tripping.