How much will solar panels produce in Swansea?

A 4 kWp system facing south at 35° tilt in Swansea produces about 4,174 kWh a year. In a weak year that is 3,494 kWh, in a good one 4,855 kWh — 1,044 kWh per kWp.

That’s about 155% of a typical home’s yearly use (2,700 kWh).

Calculate for my roof

Based on 2014–2023 satellite weather data

Production by month

0200400600800JanJanuary: 4 kWp 125 kWh, range 100–151FebFebruary: 4 kWp 210 kWh, range 162–259MarMarch: 4 kWp 361 kWh, range 280–442AprApril: 4 kWp 463 kWh, range 364–562MayMay: 4 kWp 535 kWh, range 426–644JunJune: 4 kWp 535 kWh, range 433–637JulJuly: 4 kWp 526 kWh, range 425–627AugAugust: 4 kWp 463 kWh, range 376–551SepSeptember: 4 kWp 367 kWh, range 279–455OctOctober: 4 kWp 248 kWh, range 195–300NovNovember: 4 kWp 161 kWh, range 125–197DecDecember: 4 kWp 111 kWh, range 81–142

kWh per month

A typical day in June

The sunniest month in Swansea. Output peaks around 12:00 solar time, at about 2.2 kWh in the best hour.

0:006:0012:0018:0023:00 2.2 0

Month by month

Month Weak year, kWh Typical year, kWh Good year, kWh
January 100 125 151
February 162 210 259
March 280 361 442
April 364 463 562
May 426 535 644
June 433 535 637
July 425 526 627
August 376 463 551
September 279 367 455
October 195 248 300
November 125 161 197
December 81 111 142
Year 3,494 4,174 4,855

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 Swansea?

From November to February the system produces about 608 kWh, which is 15% of the year. The weakest month (December) gives roughly 111 kWh.

Is an east-west roof worth it in Swansea?

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 Swansea

Ground mount or roof in Swansea?

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 Swansea

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