A 10 kW solar system in Marbella produces about 17,086 kWh a year on an ideally oriented roof, and a 5 kW system about 8,543 kWh, according to the European Commission’s PVGIS model. The seasonal swing is smaller than most people expect: December still delivers about 60% of July, and a Marbella December gives roughly four-fifths of what the same panel produces in Berlin in July.
This guide gives you the month-by-month numbers behind those totals, for both 5 kW and 10 kW systems, so you can see what a villa on the Costa del Sol really generates in each season. It also shows how roof tilt and direction change the result, how the Costa del Sol compares with northern Europe, and how to turn a model figure into a realistic expectation for your own roof.
Quick Answer
How much electricity do solar panels produce on the Costa del Sol? Per installed kWp, Marbella receives about 1,709 kWh a year in the PVGIS model (30° tilt, facing south, 14% system losses). Multiply by your system size: 5 kWp gives about 8,543 kWh and 10 kWp about 17,086 kWh. Real roofs are rarely perfect, so for planning we use 85–97% of the model figure, which is the 1,450–1,650 kWh per kWp range used throughout our guides. That means roughly 7,250–8,250 kWh for 5 kWp and 14,500–16,500 kWh for 10 kWp.
- 1,709 kWhAnnual output of 1 kWp, ideal roof
- 105 vs 176 kWhDecember vs July, per kWp
- 60%December output as a share of July
- ±2.8%Typical year-to-year variation
How These Figures Were Calculated
The numbers in this guide come from PVGIS, the Photovoltaic Geographical Information System run by the European Commission’s Joint Research Centre. It combines satellite-measured sunshine from 2005 to 2023 with terrain-based horizon shading to estimate the output of a solar array at a given location.
- Location: Marbella, 36.51° N, 4.88° W, elevation 24 m
- Radiation data: PVGIS-SARAH3, averaged over 2005–2023
- Panels: crystalline silicon, modelled per 1 kWp
- Mounting: fixed, 30° tilt, facing due south
- System losses: 14% (cables, inverter, dirt and similar)
- Scaling: output scales in direct proportion, so 5 kWp is 5 times and 10 kWp is 10 times the 1 kWp figures
Read this before comparing with a quote
These are modelled values for an unshaded, clean roof in good condition. Your own design will differ with shading, roof direction, panel and inverter choice. A written proposal from an installer should state the expected annual kWh and the assumptions behind it, which is the second thing to check after the price.
Month-by-Month Output: 5 kW and 10 kW Systems in Marbella
Production rises steadily from December to a plateau between May and August, then falls back. Eight months of the year, March to October, deliver about 74% of the annual total.
Monthly output of 1 kWp in Marbella (kWh)
30° tilt, facing south, 14% system losses · PVGIS-SARAH3 average 2005–2023
Estimated monthly output, Marbella (ideal roof)
| Month | 1 kWp (kWh) | 5 kWp (kWh) | 10 kWp (kWh) | 5 kWp per day | 10 kWp per day |
|---|---|---|---|---|---|
| January | 115.0 | 575 | 1,150 | 18.6 | 37.1 |
| February | 114.3 | 572 | 1,143 | 20.4 | 40.8 |
| March | 141.6 | 708 | 1,416 | 22.9 | 45.7 |
| April | 150.4 | 752 | 1,504 | 25.0 | 50.1 |
| May | 169.3 | 847 | 1,693 | 27.3 | 54.6 |
| June | 169.9 | 850 | 1,699 | 28.3 | 56.6 |
| July | 176.1 | 881 | 1,761 | 28.4 | 56.8 |
| August | 171.1 | 856 | 1,711 | 27.6 | 55.2 |
| September | 150.5 | 752 | 1,505 | 25.1 | 50.2 |
| October | 134.1 | 671 | 1,341 | 21.7 | 43.3 |
| November | 111.3 | 557 | 1,113 | 18.6 | 37.1 |
| December | 104.9 | 525 | 1,049 | 16.9 | 33.8 |
| Full year | 1,709 | 8,543 | 17,086 | 23.4 avg | 46.8 avg |
Monthly values are long-term averages. A single month can differ by roughly ±10% in either direction depending on the weather that year (PVGIS reports a standard deviation of 4–20 kWh per kWp by month). Daily columns are average kWh per day for that month.
- Best month: July176 kWh per kWp, or about 56.8 kWh a day from a 10 kWp system.
- Weakest month: December105 kWh per kWp, still about 33.8 kWh a day from 10 kWp on an average day.
- Summer vs winter shareJune to August produce about 30% of the year; December to February about 20%.
For context, an average Spanish household uses a few thousand kWh a year, while a villa with air conditioning, a pool and an EV can use several times that. That is why system size is set from your bills, not from the roof alone. If you want to understand the economics before choosing a size, see our guide to solar panel installation costs in Spain.
Do Solar Panels Work in Winter on the Costa del Sol?
Yes, and by a wide margin compared with northern Europe. The same 1 kWp of panels produces about 105 kWh in a Marbella December, against 28 kWh in Berlin, 36 kWh in London and 12 kWh in Stockholm. A Marbella December is roughly 81% of what a Berlin July delivers.
December output of 1 kWp (kWh). Marbella at 30° tilt; other cities at 35° tilt, all facing south, with the same 14% losses.
1 kWp of panels: December vs July vs full year
| Location | December (kWh) | July (kWh) | Full year (kWh) | December as % of July |
|---|---|---|---|---|
| Marbella | 104.9 | 176.1 | 1,709 | 60% |
| Madrid | 101.8 | 169.0 | 1,619 | 60% |
| London | 36.3 | 123.2 | 1,019 | 29% |
| Berlin | 28.1 | 129.8 | 1,058 | 22% |
| Amsterdam | 27.5 | 126.3 | 1,024 | 22% |
| Stockholm | 11.9 | 138.1 | 982 | 9% |
Marbella: 30° tilt, south. Other cities: 35° tilt, south, same 14% system losses, PVGIS-SARAH3. Values are long-term averages per installed kWp.
Over the whole year, 1 kWp in Marbella produces about 62% more than in Berlin (1,709 against about 1,058 kWh). This is a large part of why many northern European owners of Costa del Sol property find solar so effective here. It is also why the weaker winter months are best seen as a seasonal dip, not a stoppage: a well-designed system keeps covering part of the load all year, and the grid or a battery fills the rest.
How Roof Tilt and Direction Change the Output
Annual output is forgiving. Within about 2% of the best result, a roof can be anywhere from 20° to 45° and still face south. What changes more is when the energy arrives: low tilts push production into summer, steep tilts into winter.
How roof tilt and direction change the output of 1 kWp in Marbella
| Orientation | Full year (kWh) | vs reference | December (kWh) | July (kWh) |
|---|---|---|---|---|
| South, 30° tilt (reference) | 1,709 | 100% | 104.9 | 176.1 |
| South, 20° tilt | 1,675 | 98% | 92.8 | 183.9 |
| South, 15° tilt (low-pitch roof) | 1,643 | 96% | 85.6 | 186.5 |
| South, 45° tilt (steep) | 1,683 | 99% | 117.4 | 156.9 |
| South-east, 30° | 1,613 | 94% | 90.1 | 175.4 |
| South-west, 30° | 1,634 | 96% | 90.4 | 179.7 |
| East, 30° | 1,390 | 81% | 59.3 | 171.7 |
| West, 30° | 1,415 | 83% | 59.4 | 176.5 |
| Vertical south facade (90°) | 1,059 | 62% | 112.4 | 53.5 |
Same assumptions as above (14% system losses, PVGIS-SARAH3). The PVGIS optimum for Marbella is a 33° tilt facing 3° west of south and gives 1,712 kWh/kWp, only 0.2% more than the reference.
- Low-pitch and flat roofs (15–20°): about 98–96% of the reference per year, with July output above the reference and December about 12–18% lower. Good where summer air conditioning dominates.
- Steeper roofs (45°): about 98.5% per year, with December about 12% higher and July about 11% lower than the reference. A better match for winter heating and EV charging.
- East or west roofs: about 81–83% per year. An east-west split gives a flatter daily curve, with output in the morning and the late afternoon.
- Vertical south facade: about 62% per year, but the profile is reversed: more in December than in July. It is a niche option, not a replacement for a roof array.
The practical conclusion is that you rarely need to re-engineer a roof for tilt. Shading, available area and the pattern of your consumption usually matter more, and those are decided at the site survey and in the 3D design.
From Model to Your Roof: A Realistic Expectation
Use the model for the shape of the year, and a derating for the roof you actually have.
Approximate calculation · 10 kWp system in Marbella
- 17,086 kWhPVGIS, ideal roof
- × 85–97%shading, angle, soiling, real equipment
- 14,500–16,500 kWhplanning range per year
Halve it for 5 kWp: roughly 7,250–8,250 kWh a year. Your own figure is set during the survey.
Why a real roof produces less than the model
- shade from trees, parapets, chimneys and neighbouring buildings
- a roof direction or tilt away from the south 30° reference
- dust, pollen and Saharan dust left on the glass
- inverter limits when the array is larger than the inverter
- cable and conversion losses beyond the 14% allowance
- gradual panel ageing over the years
The model also shows how much weather varies from year to year: about ±47 kWh per kWp, or ±2.8%, on an annual basis. A cloudy year and a clear year can differ by a few percent without anything being wrong with the system. Keeping the panels clean helps; see our guide to solar panel maintenance and cleaning.
What the Seasons Mean for Your Bills and Your System
- Summer (June to August): the highest output coincides with the highest air-conditioning demand. Daytime cooling can run largely from the roof, and a battery can carry some into the evening. See our air-conditioning cost comparison. If you own a pool, the pool heating calculator shows how solar changes the bill.
- Spring and autumn: long productive days with moderate demand, so these months often produce more than a household uses at the time. What happens to that excess is covered in our guide to selling excess solar energy to the grid in Spain.
- Winter (December to February): about 60–65% of the summer output per kWp, with heating, hot water and EV charging adding load. A solar EV charger or a heat pump can use midday winter production directly.
Want these numbers for your own roof?
We combine your electricity bills, your roof geometry and a shading analysis into a written estimate of annual and monthly production, before you decide on size or battery. Request a free on-site survey
Key Takeaways
- An ideal Marbella roof produces about 1,709 kWh per kWp a year: roughly 8,543 kWh for 5 kWp and 17,086 kWh for 10 kWp.
- For planning, use 85–97% of the model figure: about 7,250–8,250 kWh for 5 kWp and 14,500–16,500 kWh for 10 kWp.
- July is the best month (176 kWh per kWp) and December the weakest (105 kWh), about 60% of July.
- A Marbella December produces nearly four times a Berlin December, and about four-fifths of a Berlin July, from the same panel.
- Any tilt from about 20° to 45° facing south stays within 2% of the best annual output.
- East and west roofs yield about 81–83% of the best annual figure, with a flatter daily profile.
- Shading, soiling and equipment make real output lower than the model, so every design needs a site survey.
Frequently Asked Questions
How many kWh does a 5 kW solar system produce in Spain per year?
On an ideally oriented roof in Marbella (30° tilt, facing south), the EU PVGIS model gives about 8,543 kWh a year for 5 kWp. For planning on a real roof, with some shading, a less than perfect angle and normal system losses, we use roughly 7,250–8,250 kWh.
How much does a 10 kW system produce per day in Marbella in December?
The long-term PVGIS average is about 33.8 kWh per day for 10 kWp in December, against 56.8 kWh per day in July. Individual days vary a lot: a bright day can exceed the average and a rainy day can fall well below it.
Do solar panels work in winter on the Costa del Sol?
Yes. A kWp in Marbella produces about 105 kWh in December, roughly 60% of its July output, and nearly four times what the same panel produces in Berlin in December. Winter is the weaker season, but it is not dead.
Which month produces the most solar energy?
July, at about 176 kWh per kWp in the model, followed closely by August and June. December is the lowest month at about 105 kWh per kWp.
What is the best angle for solar panels in Marbella?
A tilt of about 30–33° facing south gives the highest annual output. Anything between roughly 20° and 45° stays within 2% of the best annual result, so the roof you already have is usually fine. Lower tilts favour summer; steeper tilts favour winter.
How much do east-west roofs lose?
An east-facing or west-facing roof at 30° produces about 81–83% of the best annual figure in the model. An east-west split can still make sense because production is spread across the morning and the afternoon, which often suits household consumption better.
How accurate is PVGIS?
PVGIS is the European Commission’s Photovoltaic Geographical Information System and a standard planning tool. It models an unshaded, clean system. Real output also depends on shading, soiling, equipment and the weather in a particular year (about ±2.8% a year in the model), so we adjust each design after a site survey.
How many panels is a 5 kW or 10 kW system?
With modern 500 W panels, 5 kWp is about 10 panels and 10 kWp is about 20 panels. Roof space, not budget, is often the limit, which is why we measure the roof during the free survey.
Why villa owners choose KiDi Solar
- Local technical team based in Marbella
- 330+ completed projects across the Costa del Sol
- Solar panels, home batteries and EV chargers designed and installed by one company
- Legalisation and certification handled where applicable
See What Your Roof Will Produce
Send us four details and we will model the output of a system on your property:
- Your property location
- Photos or a satellite view of the roof
- Your latest electricity bills
- Any known shading, such as trees or neighbouring buildings
With this, KiDi Solar can determine:
- expected monthly and annual production
- the recommended system size
- whether a battery makes economic sense
- a quote based on your own numbers
Prefer to start with a conversation? Request a free on-site survey.
KiDi Solar installs and services systems across the Costa del Sol. For local prices, completed projects and a free survey, see our page on solar panels in Marbella.
Sources: solar production figures were calculated with PVGIS 5.3 (SARAH3 radiation database, 2005–2023) from the European Commission Joint Research Centre, for the Marbella coordinates shown above and the other cities at their city-centre coordinates, queried on 31 October 2026. Output is modelled for a fixed, unshaded, crystalline-silicon array with 14% system losses and must be recalculated for each property. The 85–97% planning derating is KiDi Solar’s working range, not a PVGIS output.