Solar Irradiance Map — Ireland
This map shows the solar energy yield across all 32 Irish counties, measured in kWh per kWp installed per year. Counties in the southeast receive the most solar radiation, but solar panels generate meaningful savings across the entire island.
Data source: PVGIS / PureVolt. Last updated February 2026.
Tap a county to see its solar yield
Solar Yield (kWh/kWp/yr)
Click any county to see local solar information. Southeast counties receive the most solar radiation.
Which Irish counties have the highest solar yield?
Solar yield varies by up to 18% across Ireland, from 817 kWh/kWp in the northwest to 965 kWh/kWp in the southeast. The table below ranks all 26 Republic of Ireland counties by solar yield, sunshine hours, annual generation from a 4 kWp system, and estimated annual savings after the SEAI grant.
| Rank | County | kWh/kWp/year | 4kWp Output | vs National Avg |
|---|---|---|---|---|
| 1 | Wexford | 965 | 3,860 kWh | +9.2% |
| 2 | Waterford | 949 | 3,796 kWh | +7.4% |
| 3 | Wicklow | 947 | 3,788 kWh | +7.1% |
| 4 | Dublin | 915 | 3,660 kWh | +3.5% |
| 5 | Carlow | 911 | 3,644 kWh | +3.1% |
| 6 | Cork | 907 | 3,628 kWh | +2.6% |
| 7 | Kilkenny | 905 | 3,620 kWh | +2.4% |
| 8 | Kerry | 896 | 3,584 kWh | +1.4% |
| 9 | Clare | 888 | 3,552 kWh | +0.5% |
| 10 | Laois | 888 | 3,552 kWh | +0.5% |
| 11 | Kildare | 885 | 3,540 kWh | +0.1% |
| 12 | Meath | 885 | 3,540 kWh | +0.1% |
| 13 | Galway | 886 | 3,544 kWh | +0.2% |
| 14 | Tipperary | 884 | 3,536 kWh | +0.0% |
| 15 | Louth | 881 | 3,524 kWh | -0.3% |
| 16 | Offaly | 881 | 3,524 kWh | -0.3% |
| 17 | Westmeath | 871 | 3,484 kWh | -1.5% |
| 18 | Limerick | 869 | 3,476 kWh | -1.7% |
| 19 | Roscommon | 867 | 3,468 kWh | -1.9% |
| 20 | Down * | 870 | 3,480 kWh | -1.6% |
| 21 | Longford | 854 | 3,416 kWh | -3.4% |
| 22 | Armagh * | 855 | 3,420 kWh | -3.3% |
| 23 | Antrim * | 850 | 3,400 kWh | -3.8% |
| 24 | Sligo | 847 | 3,388 kWh | -4.2% |
| 25 | Leitrim | 842 | 3,368 kWh | -4.8% |
| 26 | Cavan | 841 | 3,364 kWh | -4.9% |
| 27 | Mayo | 841 | 3,364 kWh | -4.9% |
| 28 | Monaghan | 841 | 3,364 kWh | -4.9% |
| 29 | Derry * | 835 | 3,340 kWh | -5.5% |
| 30 | Tyrone * | 830 | 3,320 kWh | -6.1% |
| 31 | Fermanagh * | 825 | 3,300 kWh | -6.7% |
| 32 | Donegal | 817 | 3,268 kWh | -7.6% |
National average: 884 kWh/kWp/year. Data source: PVGIS / PureVolt. Northern Ireland counties (marked *) are included for reference but are not covered by SEAI grants.
What are the key solar energy insights for Ireland?
Southeast Is Strongest
Wexford, Waterford, and Wicklow top the rankings with 947–965 kWh/kWp. The southeast enjoys the most sunshine and lowest rainfall in Ireland.
Only 18% Variation
The difference between the best (Wexford, 965) and lowest (Donegal, 817) county is just 18%. Solar panels work well across the entire island.
All Counties Viable
Even in the lowest-ranked counties, a 4kWp system generates over 3,200 kWh/year — covering 76%+ of average household electricity use. Germany, with similar irradiance, is the world's 4th largest solar market.
Frequently Asked Questions About Solar Energy by County
What is the best county for solar in Ireland?
Wexford is the best county for solar energy in Ireland with a yield of 965 kWh/kWp per year. Waterford (949) and Wicklow (947) round out the top three. The southeast receives the most solar radiation due to lower rainfall and more sunshine hours. However, all 26 Republic of Ireland counties generate enough solar energy to make panels worthwhile.
Why does Wexford rank highest for solar?
Wexford tops the Irish solar rankings because it receives the most annual sunshine hours and has the lowest average rainfall in Ireland. Its coastal southeast location benefits from clearer skies and longer summer days. A 4kWp system in Wexford generates approximately 3,860 kWh per year — 9% above the national average.
Does solar work in the west of Ireland?
Yes, solar panels work well in western counties like Galway (886 kWh/kWp), Clare (888), and Kerry (896). While the west receives slightly more rainfall, the difference from the national average is only 2–6%. A 4kWp system in Galway still generates over 3,500 kWh/year — enough to cover most household electricity needs.
How much does location matter for solar panels in Ireland?
Location matters less than most people think. The difference between Ireland's best county (Wexford, 965 kWh/kWp) and lowest (Donegal, 817 kWh/kWp) is just 18%. Roof orientation, pitch, and shading have a bigger impact on output than county. Even the lowest-ranked counties generate over 3,200 kWh per year from a 4kWp system.
What is solar yield?
Solar yield measures how much electricity a solar panel system generates per kilowatt-peak installed, expressed as kWh/kWp per year. In Ireland, solar yield ranges from 817 kWh/kWp (Donegal) to 965 kWh/kWp (Wexford), with a national average of 884 kWh/kWp. Higher yield means more electricity generated per panel.
How is kWh/kWp calculated?
kWh/kWp is calculated by dividing the total annual electricity output (kilowatt-hours) by the system's peak capacity (kilowatt-peak). For example, a 4kWp system in Dublin generating 3,660 kWh/year has a yield of 915 kWh/kWp. The figures on this map are based on PVGIS satellite data for each county's average solar irradiance.
Sources
- PVGIS — Photovoltaic Geographical Information System — European Commission JRC
- SEAI — Solar Electricity for the Home — seai.ie
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