What it yields where you are

How much solar produces in Genova

In Genova a well-oriented system produces 1,381 kWh a year for every kWp installed. A 6 kW system — a home-sized one — makes about 8,283 kWh a year. The figures below come from PVGIS, the European Commission's database.

1,381

kWh a year for every kWp

8,283

kWh a year from a 6 kW system

38°

the best tilt, facing south

01At a glance

A year of sun in Genova.

A 6 kW system produces

8,283 kWh

About what 4.1 households use in a year.

The best month

July

957 kWh: 2.3 times the worst month.

Hours of sunshine a year

3,452 h

9.5 hours a day on average. In the leanest month it drops to 5.9.

How cloudy the sky is

52%

Average over the year. The cloudiest month is November, at 61%.

Warmest month's temperature

25.1 °C

In the coldest month the average is 7.7 °C.

How much it changes year to year

from −7% to +7%

Sunlight measured over the last twenty years, against the average.

02System sizes

How much a system produces in Genova

The three sizes people actually put on a house, on the best plane.

  • 3 kW

    4,142

    Produces each year · kWh

    450 W modules: 7

  • 6 kW

    8,283

    Produces each year · kWh

    450 W modules: 13

  • 10 kW

    13,805

    Produces each year · kWh

    450 W modules: 22

03Month by month

Month by month in Genova

A yearly total doesn't say when the energy arrives, and that's the part that decides whether you need storage.

957
408
average 690 kWh
JFMAMJJASOND

A 6 kW system yields most in July, with 957 kWh, and least in December, with 408: 2.3 times as much. That's why the summer bill goes to zero and the winter one doesn't.

MonthOutput of 6 kWSunshineCloudTemperatureDays above 30°C
January459 kWh201 h56%7.7 °C—
February517 kWh188 h59%9.0 °C—
March720 kWh273 h54%10.9 °C—
April780 kWh319 h54%13.9 °C—
May844 kWh346 h60%17.4 °C—
June873 kWh392 h50%21.9 °C2
July957 kWh430 h37%24.8 °C8
August905 kWh380 h36%25.1 °C12
September774 kWh317 h45%21.0 °C2
October602 kWh233 h57%16.8 °C—
November440 kWh193 h61%11.9 °C—
December408 kWh180 h59%8.9 °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 24 days above 30 °C a year, nearly all between June and August. 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 Genova is: compared with a south-facing roof you lose about 21% facing east and 20% facing west, at the same tilt. Less than people expect — an awkward roof is still a good roof.

  • South-facing, 30°

    1,369 kWh/kWp

    The benchmark

  • East-facing, 30°

    1,080 kWh/kWp

    −21% compared with south

  • West-facing, 30°

    1,090 kWh/kWp

    −20% 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.

average
20052024

Over twenty years the poorest was 2014: 7% below average. The most generous was 2022: 7% 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

1,381 kWh/kWp

How many kWh each kW of panels gives in a year, on the best possible roof.

Best tilt

38°

The angle worth using here, facing south.

Sunlight reaching the ground

1,478 kWh/m²

Solar energy landing on one flat square metre in a year.

Where these figures come from. From irradiation measured by PVGIS, the European Commission's Joint Research Centre service, averaged over the nineteen years from 2005 to 2023. The tilted-plane calculation is ours, day by day, and the figures account for the terrain around each city — measured on PVGIS too. What stays out is nearby obstacles: a tree, the building next door, a chimney. For those we need your address.

Other cities

Your roof isn't an average.

These figures are for an ideal roof in Genova. The estimate on your address accounts for your roof, the shade and your consumption: two minutes, without leaving your contact details.