How to lower your contracted power (and save without even noticing)

There's one overcharge almost nobody reviews, and it turns up on your bill every month come rain or shine: the power term. You pay it for having a certain number of kilowatts available, whether you use them or not. And a great many homes have more contracted than they need, sometimes since the day the building went up.

It's the dullest saving there is and also the surest: it doesn't depend on you using less, on moving the washing machine to a different hour, or on the market being cheap. It's money you stop paying every single day of the year.

What contracted power actually is

Power (in kilowatts, kW) is the maximum you can have running at the same time. It's the "width of the pipe" of your installation: the wider it is, the more simultaneous appliances it takes, but the more you pay as a fixed charge every day.

Don't confuse the two concepts on your bill:

• Power (kW) is capacity. You pay for having it available, 365 days a year.
• Consumption (kWh) is what you actually use. You pay for using it.

You can go away for a month with everything switched off: your consumption will be zero and the power term will be charged just the same.

On the 2.0TD tariff you can contract two different values: one for peak and standard hours (8:00 to 24:00 on working days) and another for off-peak (0:00 to 8:00 and the whole weekend). Adjusting either of them shows up in the fixed part of your bill, and the peak one is the expensive one. We set out the bands in electricity prices by time of day.

The sign that you have more than you need

The clearest clue is a simple one: if your main breaker (the ICP) never trips, you can very probably lower your power without noticing any change in your day-to-day life.

Think about your worst moment of the year: oven on, hob at full blast, dishwasher running, air conditioning going and somebody drying their hair, all at once. If the power doesn't cut out even then, you've got plenty to spare.

There are three situations in which there's almost always power going spare:

• Flats with power inherited from the developer. It was contracted on a worst-case basis, for any tenant you could imagine, and nobody has touched it since.
• Homes where the cooker switched to induction or gas. The hungriest appliance in the house changed and the contracted power didn't.
• Homes where the family has shrunk. Fewer people, less running at the same time.

How to work out what you really need

It's a back-of-an-envelope sum, not an engineering calculation:

1. List what you use at the same time, not everything in the house. Nobody runs the oven, the washing machine, the tumble dryer and the air conditioning simultaneously.
2. Add up their power ratings. As an order of magnitude: oven 2-2.5 kW, hob 1.5-2 kW per ring in use, washing machine 2-2.2 kW (only while it's heating water), dishwasher 1.5-2 kW, tumble dryer 2-2.5 kW, air conditioning 0.7-1.5 kW per unit, electric water heater 1.5-2 kW, microwave 1-1.5 kW, iron 1-2 kW. Fridge, lights, television and router together come to about 0.3-0.5 kW and are always on.
3. Add a margin of 20-30% for start-up spikes: motors (fridge, washing machine, air conditioning) draw more in the instant they start than they do while running.
4. Round up to the nearest standard step. The usual ones in homes are 3.45 · 4.6 · 5.75 · 6.9 · 8.05 · 9.2 kW.

Plenty of homes contract 4.6 or 5.75 kW out of sheer inertia when 3.45 kW would be more than enough. Every step you go down is fixed money you stop paying every day.

A shortcut that beats the sum: if your meter is digital (and it is in practically all of Spain), the distributor knows what your actual maximum demanded power has been, month by month. That's the exact figure you're after, measured in your home rather than estimated. You can look it up in the distributor's online office, and it sometimes appears on the bill itself as "maximeter" or "maximum recorded power".

How much you really save

The power term is charged per kW and per day, so the saving is steady and predictable: dropping one step usually means between €30 and €60 a year, without changing a single habit. Dropping two, twice that.

It isn't the most spectacular saving you'll see advertised, but it has two virtues no tariff offer has: it doesn't depend on anything and it doesn't expire. There's no promotional price that renews itself at a worse one the following year.

How to make the change

1. Call or write to your retailer (not the distributor: the retailer handles it for you).
2. State the new power you want, for peak and for off-peak.
3. Wait for the change. In the overwhelming majority of cases nobody needs to come to your home: with a digital meter, the power is reprogrammed remotely.
4. Check your next bill to confirm the change has been applied.

Careful with how often you do it. Lowering your power is free once every twelve months. If you change it more than once in that period, there may be network access or equipment charges. That's why it's worth getting the calculation right first time rather than experimenting.

And if you come up short, you can raise it again — but then there usually is a cost, and in some cases the property's electrical installation certificate (boletín eléctrico) has to be updated. Adjust sensibly, not right to the limit.

When lowering it is NOT a good idea

In fairness, there are cases where this advice doesn't apply:

• If you have an electric car. Charging needs sustained power. The smart move here isn't to lower it but to split it: just enough power at peak and more headroom off-peak, which is the cheap band and the time you charge.
• If you have a heat pump or air-source heating. They're the big simultaneous load of the winter.
• If your ICP trips once or twice a year. You're already at the limit. Lowering it would mean reorganising how you use your appliances, and that's no longer "saving without even noticing".

Let us do the maths for you

Working it out by hand is possible, but it's easy to end up too low — and have the power cutting out every time you switch the oven on — or too high, and keep overpaying. And the part that really decides it, the maximum power you've genuinely demanded, is in your own data, not in a generic table.

At luzgasia you upload your bill, we read your contracted power and your consumption profile, and we tell you whether you can adjust it and how much you'd save — alongside all the other levers, because power almost never travels alone. Have a look through the 5 signs you're paying too much as well.

It's free, with no strings attached and no sales calls. Analyse your bill now and settle the question today.