How much will solar panels produce in Viseu?

A 5 kWp system facing south at 35° tilt in Viseu produces about 7,620 kWh a year. In a weak year that is 6,368 kWh, in a good one 8,873 kWh — 1,524 kWh per kWp.

That’s about 254% of a typical home’s yearly use (3,000 kWh).

Calculate for my roof

Based on 2014–2023 satellite weather data

Production by month

05001,0001,500JanJanuary: 5 kWp 466 kWh, range 331–602FebFebruary: 5 kWp 482 kWh, range 344–619MarMarch: 5 kWp 633 kWh, range 479–787AprApril: 5 kWp 648 kWh, range 507–788MayMay: 5 kWp 782 kWh, range 639–925JunJune: 5 kWp 745 kWh, range 610–881JulJuly: 5 kWp 873 kWh, range 726–1,021AugAugust: 5 kWp 883 kWh, range 736–1,030SepSeptember: 5 kWp 720 kWh, range 574–866OctOctober: 5 kWp 561 kWh, range 426–696NovNovember: 5 kWp 399 kWh, range 255–542DecDecember: 5 kWp 415 kWh, range 309–522

kWh per month

A typical day in August

The sunniest month in Viseu. Output peaks around 11:00 solar time, at about 3.2 kWh in the best hour.

0:006:0012:0018:0023:00 3.2 0

Month by month

Month Weak year, kWh Typical year, kWh Good year, kWh
January 331 466 602
February 344 482 619
March 479 633 787
April 507 648 788
May 639 782 925
June 610 745 881
July 726 873 1,021
August 736 883 1,030
September 574 720 866
October 426 561 696
November 255 399 542
December 309 415 522
Year 6,368 7,620 8,873

The months don’t add up exactly to the yearly figure, because each one is the typical value across many years.

Common questions

How much do solar panels produce in winter in Viseu?

From November to February the system produces about 1,762 kWh, which is 23% of the year. The weakest month (November) gives roughly 399 kWh.

Is an east-west roof worth it in Viseu?

An east-west system typically produces 10–25% less per kWp than one facing south, but spreads production more evenly through the day. The exact difference depends on tilt and shading.

Compare an east-west roof for Viseu

Ground mount or roof in Viseu?

A ground mount can be tilted and aimed freely, which can add some yield, but it costs more and needs space. Compare both for your own plot.

Check a ground-mounted system in Viseu

Your roof is not an average roof

Set your own tilt, direction, shading and inverter limit and get a range for your address.

Calculate for my roof

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Climate data: Photovoltaic Geographical Information System (PVGIS) — European Commission, Joint Research Centre