Learning Zone · Updated 2026 guide
Solar radiation in Europe: how much electricity does a photovoltaic system really generate?
A plain-language guide to solar PV output, with PVGIS tables for major cities in Italy and Spain and a comparison with France, Germany and the rest of Europe.
Solar radiation and photovoltaics, without the jargon
The Sun sends energy towards Earth. Some reaches the panels directly, some is scattered by the atmosphere and clouds, and some is reflected by the ground. Photovoltaic modules turn part of that light energy into electricity. This is why solar panels still generate electricity under cloudy skies, although less than on a clear day.
The solar power received at a particular moment, measured in W/m². Think of it as the flow rate from a tap.
The solar energy accumulated over a period, measured in kWh/m². Think of it as the water collected in a bucket.
The electricity available after system losses, measured in kWh. This is the number that matters on an energy bill.
Three useful acronyms: GHI, DNI and GTI
On a smartphone: swipe the table horizontally to view all columns.
| Acronym | What it measures | Why it matters |
|---|---|---|
| GHI | Global radiation on a horizontal surface. | A general comparison of the solar resource. |
| DNI | Direct radiation on a surface perpendicular to the Sun’s rays. | Mainly relevant to concentrating solar power and trackers. |
| GTI | Global radiation on the tilted plane of the modules. | The closest measure to what a PV array actually receives. |
The most common mix-up: kW and kWp describe power; kWh describes energy. A 6 kWp system does not generate 6 kWh a year. Across the cities analysed here it can generate roughly 7,200 to more than 10,500 kWh per year.
How to read the solar output tables
The key figure is specific yield: the average number of kWh generated by each installed kWp in one year. If a city shows 1,500 kWh/kWp and the system is rated at 6 kWp, the quick estimate is:
This is not a guarantee. Shading, the actual roof orientation, temperature, dirt, system availability, inverter clipping and year-to-year weather all change the result.
Solar PV output table for Italy
Photovoltaic output by city in Italy
The sample generally rises from northern towards central and southern Italy, but not in a perfectly straight line: local cloud cover, terrain, aerosols and temperature all influence the result. Cagliari exceeds 1,630 kWh/kWp per year, while the northern cities analysed sit around 1,400–1,420 kWh/kWp.
On a smartphone: swipe the table horizontally to view all columns.
| City | kWh/kWp/year | 3 kWp | 6 kWp | 10 kWp | Optimal tilt |
|---|---|---|---|---|---|
| Milan | 1,420 | 4,259 | 8,518 | 14,197 | 39° |
| Turin | 1,406 | 4,219 | 8,439 | 14,065 | 40° |
| Venice | 1,414 | 4,242 | 8,485 | 14,142 | 38° |
| Bologna | 1,412 | 4,235 | 8,471 | 14,118 | 38° |
| Florence | 1,422 | 4,266 | 8,533 | 14,221 | 37° |
| Rome | 1,557 | 4,670 | 9,340 | 15,567 | 37° |
| Naples | 1,580 | 4,739 | 9,477 | 15,795 | 36° |
| Bari | 1,528 | 4,585 | 9,170 | 15,284 | 35° |
| Palermo | 1,583 | 4,749 | 9,499 | 15,831 | 32° |
| Cagliari | 1,636 | 4,907 | 9,814 | 16,357 | 35° |
Solar radiation in Spain
Photovoltaic output by city in Spain
Spain contains very different solar climates. Bilbao’s Atlantic conditions reduce specific yield, while Madrid, Valencia, Murcia, Seville and Malaga reach or exceed roughly 1,700 kWh/kWp per year. “Sunny Spain” is broadly true, but far too vague for sizing a system.
On a smartphone: swipe the table horizontally to view all columns.
| City | kWh/kWp/year | 3 kWp | 6 kWp | 10 kWp | Optimal tilt |
|---|---|---|---|---|---|
| A Coruña | 1,318 | 3,955 | 7,910 | 13,184 | 36° |
| Bilbao | 1,208 | 3,624 | 7,248 | 12,081 | 36° |
| Valladolid | 1,604 | 4,813 | 9,626 | 16,044 | 36° |
| Barcelona | 1,612 | 4,835 | 9,671 | 16,118 | 38° |
| Zaragoza | 1,665 | 4,996 | 9,992 | 16,653 | 38° |
| Madrid | 1,676 | 5,027 | 10,054 | 16,756 | 37° |
| Valencia | 1,683 | 5,049 | 10,099 | 16,831 | 37° |
| Murcia | 1,687 | 5,061 | 10,122 | 16,871 | 35° |
| Seville | 1,739 | 5,218 | 10,437 | 17,395 | 34° |
| Malaga | 1,752 | 5,257 | 10,515 | 17,525 | 34° |
European overview
France, Germany and other European cities
Europe is not simply divided into a “sunless north” and “sunny south”. In this model Marseille exceeds Athens and Lisbon, Munich produces more than Berlin, and Paris is close to Munich. Solar works in northern Europe too, but more installed power or surface area is needed to obtain the same annual energy.
On a smartphone: swipe the table horizontally to view all columns.
| City | Country | kWh/kWp/year | 6 kWp system |
|---|---|---|---|
| Dublin | Ireland | 1,010 | 6,059 kWh |
| Stockholm | Sweden | 1,016 | 6,099 kWh |
| Amsterdam | Netherlands | 1,055 | 6,328 kWh |
| Copenhagen | Denmark | 1,079 | 6,474 kWh |
| Warsaw | Poland | 1,084 | 6,505 kWh |
| Berlin | Germany | 1,085 | 6,508 kWh |
| Paris | France | 1,165 | 6,988 kWh |
| Munich | Germany | 1,175 | 7,052 kWh |
| Vienna | Austria | 1,211 | 7,267 kWh |
| Lisbon | Portugal | 1,624 | 9,746 kWh |
| Athens | Greece | 1,628 | 9,768 kWh |
| Marseille | France | 1,664 | 9,986 kWh |
Solar PV output month by month
Annual totals hide seasonality. The table shows estimated monthly kWh for 1 kWp. For a 6 kWp system, multiply each value by six.
On a smartphone: swipe the table horizontally to view all columns.
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Milan | 81 | 91 | 130 | 137 | 144 | 151 | 164 | 153 | 131 | 99 | 70 | 68 | 1,420 |
| Rome | 92 | 104 | 130 | 142 | 153 | 158 | 172 | 166 | 140 | 123 | 91 | 86 | 1,557 |
| Madrid | 111 | 116 | 142 | 146 | 158 | 160 | 176 | 173 | 152 | 132 | 104 | 105 | 1,676 |
| Seville | 123 | 122 | 146 | 150 | 164 | 163 | 175 | 173 | 154 | 139 | 117 | 115 | 1,739 |
These are long-term climate averages, not a weather forecast. The gap between July and December is much larger in Milan than in Seville, which matters when sizing a battery or assessing winter self-consumption.
Quick photovoltaic output calculator
Use this manual calculator with the tables in this guide. It needs no script, works on every smartphone and keeps the complete method visible to search engines.
On a smartphone, swipe the table horizontally to see every column.
| System size | Selected yield | Annual output | Monthly average | Daily average |
|---|---|---|---|---|
| 3 kWp | 1,500 kWh/kWp | 4,500 kWh | 375 kWh | 12.3 kWh |
| 6 kWp | 1,500 kWh/kWp | 9,000 kWh | 750 kWh | 24.7 kWh |
| 10 kWp | 1,500 kWh/kWp | 15,000 kWh | 1,250 kWh | 41.1 kWh |
Pick the nearest city in the tables; multiply its specific yield by installed kWp; divide by 12 or 365 only for an average. For example, 6 kWp in Rome is about 9,340 kWh/year, while 6 kWp in Madrid is about 10,054 kWh/year.
Monthly and daily averages hide seasonality. Summer output is much higher than winter output. Enter actual shade, orientation, tilt and losses in PVGIS.
Open PVGIS for a roof-specific calculation
How to estimate the output of your own system
Use the table for an initial estimate, not as a final design.
Specific yield × the system’s rated peak power.
Account for the roof, orientation, shadows, inverter and availability.
Five factors that can materially change the result
- Shading: Chimneys, trees, buildings and terrain can reduce output at specific times.
- Orientation and tilt: South often maximises annual energy; east–west spreads generation across more hours.
- Temperature: More light helps, but hotter solar cells lose instantaneous efficiency.
- Electrical losses: Cables, inverter, mismatch and dirt are not invisible details.
- Annual variability: A cloudier or sunnier year can deviate from the multi-year average.
Method and limitations
The estimates were calculated on 4 September 2026 with PVGIS 5.3 from the Joint Research Centre. Inputs: city-centre coordinates, PVGIS-SARAH3 database (2005–2023), crystalline-silicon modules with the updated 2025 coefficients, 1 kWp, free-standing fixed mounting, optimised tilt and azimuth, terrain horizon enabled and 14% system losses.
Free-standing mounting cools modules better than building integration. These tables are designed for comparison and preliminary sizing. They do not replace a site visit, a shading study or a professional yield assessment.
Frequently asked questions about solar output
How much does a 6 kW solar system generate?
Strictly speaking, 6 kWp. In the cities studied, the estimate ranges from about 7,248 kWh/year in Bilbao to 10,515 kWh/year in Malaga. In Italy it is about 8,439 kWh in Turin, 9,340 kWh in Rome and 9,814 kWh in Cagliari.
How much does solar generate per day?
Divide the annual kWh by 365 for an annual daily average, but this hides major seasonal differences. A 6 kWp system in Rome averages about 25.6 kWh/day over a full year and produces much more in July than in December.
Do solar panels work in winter or under clouds?
Yes. They use both direct and diffuse radiation. Shorter days and thicker cloud reduce the available energy, while cooler cells can operate more efficiently when light is present.
Why does Spain not generate more than Italy everywhere?
Because political borders do not control clouds. Atlantic Spain is very different from Andalusia: Bilbao is below every Italian city in the table, while Malaga and Seville are among the highest-yield locations.
How can I run a precise PVGIS calculation?
Enter the exact coordinates, rated kWp, mounting type, real tilt and orientation, and realistic losses. Then compare the result with consumption, the hourly load profile and site shading.
From a table to a real solar project
Annual output is only half the story: a good system also needs coherent dimensions, voltages, inverter sizing and consumption profile. Read our guide to solar panels for the home or explore custom photovoltaic panels.
Sources and scientific studies
- European Commission, Joint Research Centre — PVGIS.
- PVGIS 5.3 — API documentation and calculation parameters.
- Martinez et al. (2026), Photovoltaics Geographical Information System: Status Report 2025, doi:10.2760/8197535.
- Chatzipanagi et al. (2025), An Updated Simplified Energy Yield Model for Recent Photovoltaic Module Technologies, Progress in Photovoltaics, doi:10.1002/pip.3926.
- Urraca et al. (2018), Extensive validation of CM SAF surface radiation products over Europe, Remote Sensing of Environment, doi:10.1016/j.rse.2017.07.013.
- Huld et al. (2011), A power-rating model for crystalline silicon PV modules, Solar Energy Materials and Solar Cells, doi:10.1016/j.solmat.2011.07.026.