Solar panels in winter in Mallorca: how much they really produce

Yes, they produce: in December, just over half of July

In Palma, each south-facing kWp produces about 89 kWh in December, the weakest month, and about 172 kWh in July, the best: in midwinter you get just over half of the summer output. A typical 5 kWp system generates about 445 kWh in December and about 860 kWh in July.

Over the whole year the same kWp produces about 1,575 kWh in Palma. Returns are calculated on the full year: summer more than makes up for the short months.

Why output drops in winter (and why cold is not the problem)

Winter brings fewer daylight hours and a lower sun, so less energy reaches each square metre of panel. Cold, on the other hand, does no harm: modules perform slightly better when cool than in the heat of August.

Terrain does matter. In Sóller the mountains block the low winter sun and December drops to about 62 kWh per kWp, 30% less than Palma. That is why we study each roof’s shading month by month, not just the yearly total.

Getting more from your panels in winter

A few design and usage choices make a big difference in the colder months:

• Tilt: a slightly steeper angle favours the low winter sun. We adjust it to your roof and usage.
• Heat pump plus solar: scheduling heating and hot water for sunny hours uses the output when it is needed most.
• Battery: stores the midday surplus for the afternoon and evening, when winter consumption is higher.
• Hot water from surplus: excess power can heat the tank instead of being sold to the grid at a low price.

Check your own roof

Output depends on each home’s orientation, tilt and shading. Our online solar study lets you draw your roof on the aerial photo and calculates production and savings with your location’s data.