What it yields where you are
How much solar produces in Lecce
In Lecce a well-oriented system produces 1,518 kWh a year for every kWp installed. A 6 kW system — a home-sized one — makes about 9,105 kWh a year. The figures below come from PVGIS, the European Commission's database.
1,518
kWh a year for every kWp
9,105
kWh a year from a 6 kW system
35°
the best tilt, facing south
01At a glance
A year of sun in Lecce.
A 6 kW system produces
9,105 kWh
About what 4.6 households use in a year.
The best month
July
1,003 kWh: 2.0 times the worst month.
Hours of sunshine a year
3,746 h
10.3 hours a day on average. In the leanest month it drops to 7.1.
How cloudy the sky is
40%
Average over the year. The cloudiest month is November, at 55%.
Warmest month's temperature
27.2 °C
In the coldest month the average is 9.5 °C.
How much it changes year to year
from −4% to +4%
Sunlight measured over the last twenty years, against the average.
02System sizes
How much a system produces in Lecce
The three sizes people actually put on a house, on the best plane.
3 kW
4,553
Produces each year · kWh
450 W modules: 7
6 kW
9,105
Produces each year · kWh
450 W modules: 13
10 kW
15,175
Produces each year · kWh
450 W modules: 22
03Month by month
Month by month in Lecce
A yearly total doesn't say when the energy arrives, and that's the part that decides whether you need storage.
A 6 kW system yields most in July, with 1,003 kWh, and least in December, with 502: 2.0 times as much. That's why the summer bill goes to zero and the winter one doesn't.
| Month | Output of 6 kW | Sunshine | Cloud | Temperature | Days above 30°C |
|---|---|---|---|---|---|
| January | 545 kWh | 231 h | 52% | 9.5 °C | — |
| February | 580 kWh | 239 h | 48% | 10.7 °C | — |
| March | 779 kWh | 294 h | 48% | 11.9 °C | — |
| April | 841 kWh | 328 h | 45% | 14.8 °C | — |
| May | 914 kWh | 374 h | 45% | 19.0 °C | 1 |
| June | 924 kWh | 400 h | 29% | 24.2 °C | 12 |
| July | 1,003 kWh | 428 h | 11% | 27.2 °C | 24 |
| August | 971 kWh | 400 h | 18% | 27.0 °C | 24 |
| September | 812 kWh | 326 h | 36% | 23.1 °C | 7 |
| October | 702 kWh | 288 h | 46% | 18.7 °C | — |
| November | 529 kWh | 215 h | 55% | 14.9 °C | — |
| December | 502 kWh | 223 h | 50% | 11.2 °C | — |
Heat costs yield: above 25 °C of cell temperature a panel loses about 0.4% per degree, and in summer the cell runs some twenty degrees above the air. Here there are 68 days above 30 °C a year, nearly all between June and September. That loss is already inside the figures above — don't subtract it twice — but it is why July, which gets the most sun of any month, never yields as much as the extra sun would suggest.
Output: our own calculation on PVGIS irradiation, calibrated against PVGIS city by city and month by month. Sunshine, cloud, temperature and hot days: ten-year averages 2015-2024 from the ERA5 reanalysis, via Open-Meteo. Two different sources, in separate columns on purpose.
04Orientation
And if the roof doesn't face south
Everyone asks this, and the answer in Lecce is: compared with a south-facing roof you lose about 19% facing east and 19% facing west, at the same tilt. Less than people expect — an awkward roof is still a good roof.
South-facing, 30°
1,512 kWh/kWp
The benchmark
East-facing, 30°
1,231 kWh/kWp
−19% compared with south
West-facing, 30°
1,227 kWh/kWp
−19% compared with south
05The years
And if next year is cloudy?
Fair question: the sun isn't the same every year. Here is how much it actually varied, from 2005 to 2024.
Over twenty years the poorest was 2018: 4% below average. The most generous was 2017: 4% above. Every other year sits in between. That's why a solar estimate uses the average of many years and not the last one — a bad year doesn't change the maths of a system that lasts twenty-five.
Yearly irradiation from 2005 to 2024 according to the ERA5 reanalysis, via Open-Meteo, against its own average. This is a different database from the one behind the output figures above, which comes from PVGIS and stops at 2023 — which is why the two periods don't match.
06For designers
The technical figures
The ones a designer needs. If you don't know them, you don't need them: everything is above.
Yield per installed kW
1,518 kWh/kWp
How many kWh each kW of panels gives in a year, on the best possible roof.
Best tilt
35°
The angle worth using here, facing south.
Sunlight reaching the ground
1,698 kWh/m²
Solar energy landing on one flat square metre in a year.
Other cities
Your roof isn't an average.
These figures are for an ideal roof in Lecce. The estimate on your address accounts for your roof, the shade and your consumption: two minutes, without leaving your contact details.