Energy at home
Why your bill soars in summer on the coast (and what can be done)
In Estepona and Marbella the August bill looks nothing like the March one. It is not a feeling: it is arithmetic, and it comes down to how many hours the air conditioning is on.
A normal domestic split unit uses between 0.5 and 1.5 kWh for every hour it is running. Multiply that by the real hours of an August here, across several rooms, and it is easy to add €150 to €180 extra a month.
On the coast this shows up more than inland for two reasons. The nights often do not cool down enough to turn the air conditioning off, and a good share of the homes in the area are large houses or penthouses with a lot of south-facing glass.
What is interesting is that this consumption peak coincides almost exactly with the sunniest hours. And that overlap is precisely what makes self-consumption work so well around here.
The first step is not new equipment, it is how you use it
Before spending a euro there are three things that genuinely move the needle.
The temperature. Every degree below 24 or 25 °C sends consumption up. Setting it to 21 °C does not cool the room any faster: it just makes the unit run for longer.
Maintenance. A dirty filter pushes up consumption without you noticing, because the unit compensates by working harder.
And passive measures: awnings, blinds down during hours of direct sun and cross-ventilation at night. It sounds like your grandmother's advice, but in a south-facing house the difference is very real.
If your unit is more than ten years old and is not an inverter model, there is room for new equipment: inverter models can use up to 40% less than older ones.
In August, air conditioning can be more than half your bill.
Where heat pumps come in
A heat pump does not create cold or heat: it moves it. For every kWh of electricity it uses it delivers between 3 and 5 kWh of thermal energy. That is the whole trick, and it is why it is the most efficient climate system installed today.
In practice, a properly sized unit in a medium-sized home runs on very low figures in summer, well below what a set of old split units uses doing the same job.
That said, let us be fair: if you already have good modern splits, replacing them for cooling alone rarely adds up. A heat pump shines when it handles heating, cooling and hot water with a single unit. That is where the numbers genuinely work.
The combination that does work here
Efficient climate control plus self-consumption. That is the pairing that makes sense in this area, and not for marketing reasons: because the curves line up.
Your home asks for most cooling exactly when the panels are generating flat out. It is one of the few cases where generation and consumption overlap naturally, with no need for a battery to take advantage of it.
In winter things change and you generate less, but you also need far less heating and cooling here than inland.
If you want to know what share of your summer you could cover with your own generation, we need to look at your consumption hour by hour, not the monthly average. It is the first thing we ask for, and it comes from your own bill.
