How much will solar panels produce in Galway?

A 4 kWp system facing south at 35° tilt in Galway produces about 3,630 kWh a year. In a weak year that is 3,034 kWh, in a good one 4,226 kWh — 908 kWh per kWp.

That’s about 86% of a typical home’s yearly use (4,200 kWh).

Calculate for my roof

Based on 2014–2023 satellite weather data

Production by month

0200400600800JanJanuary: 4 kWp 118 kWh, range 88–148FebFebruary: 4 kWp 183 kWh, range 145–221MarMarch: 4 kWp 305 kWh, range 232–377AprApril: 4 kWp 429 kWh, range 324–534MayMay: 4 kWp 524 kWh, range 423–624JunJune: 4 kWp 455 kWh, range 363–546JulJuly: 4 kWp 437 kWh, range 361–512AugAugust: 4 kWp 409 kWh, range 340–478SepSeptember: 4 kWp 305 kWh, range 246–363OctOctober: 4 kWp 218 kWh, range 175–261NovNovember: 4 kWp 139 kWh, range 109–168DecDecember: 4 kWp 101 kWh, range 71–131

kWh per month

A typical day in May

The sunniest month in Galway. Output peaks around 11:00 solar time, at about 1.8 kWh in the best hour.

0:006:0012:0018:0023:00 1.8 0

Month by month

Month Weak year, kWh Typical year, kWh Good year, kWh
January 88 118 148
February 145 183 221
March 232 305 377
April 324 429 534
May 423 524 624
June 363 455 546
July 361 437 512
August 340 409 478
September 246 305 363
October 175 218 261
November 109 139 168
December 71 101 131
Year 3,034 3,630 4,226

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 Galway?

From November to February the system produces about 540 kWh, which is 15% of the year. The weakest month (December) gives roughly 101 kWh.

Is an east-west roof worth it in Galway?

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 Galway

Ground mount or roof in Galway?

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 Galway

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