Solar panel installation in El Campello

A large share of El Campello property is occupied for part of the year and empty for the rest.

That pattern has a direct and often overlooked effect on whether a solar installation is a good investment.

What an empty house does to your solar economics

Solar pays through self-consumption. The electricity you use as you generate it is worth what you would otherwise have paid to import; the surplus you export is compensated at a substantially lower rate. Every honest solar calculation turns on that gap, and a property that is empty for eight months of the year sits on the wrong side of it for most of the calendar.

A house occupied only in July and August generates all spring and autumn with almost nothing running. That generation is not wasted — it is exported and compensated — but it earns a fraction of what the same kilowatt-hour would have saved if someone had been there to use it. Sizing such a property as though it were permanently occupied produces an array that looks impressive and pays back slowly.

The sensible response is usually a smaller array matched to the loads that run all year regardless of occupancy: a pool pump on a maintenance cycle, a fridge or freezer left running, dehumidifiers, an irrigation controller, security equipment. Those are modest but genuinely continuous, and an array sized around them plus peak-season use has a much better ratio of self-consumption to export.

If the property is let commercially rather than left empty, the calculation changes completely and improves. A holiday let occupied for much of the summer with air conditioning running through the afternoon has exactly the daytime consumption profile solar wants, and there the case is straightforward.