Solar Irradiance Ireland by County:
Solar PV Yield & Production Data
Compare solar irradiance in Ireland by county using PVGIS-SARAH3 data. See annual solar PV yield in kWh/kWp, estimated output for common system sizes, and which counties receive the strongest solar production.
Data last checked: 20 August 2026. This page uses PVGIS 5.3/SARAH3 representative-point estimates for a 1 kWp crystalline silicon system using the original/default PVGIS module model, with a 35° tilt, south-facing orientation, calculated horizon and 14% system losses.
| What is Ireland’s average solar yield? | The simple average of the 26 representative-point estimates is 928 kWh/kWp/year. At that modelled yield, each 1 kWp of panels would produce about 928 kWh per year before considering how the electricity is used, stored or exported. |
|---|---|
| Which county performs best? | The Wexford representative point ranks highest at 1,046 kWh/kWp/year, followed by Waterford, Dublin, Louth and Cork. |
| Which county is lowest? | The Donegal representative point ranks lowest in this dataset at 817 kWh/kWp/year, but an illustrative 4 kWp system still produces an estimated 3,268 kWh per year. |
| What does kWh/kWp mean? | kWh/kWp is annual electricity output per kilowatt-peak of installed solar panels. To estimate annual output, multiply your county yield by your system size. |
| Does solar work across Ireland? | Yes. The representative-point range is 229 kWh/kWp/year, about 22% of the highest estimate. Roof direction, pitch and shading affect generation, while household usage, export rates and battery choices affect its financial value. |
How to Estimate Solar Output from kWh/kWp
PVGIS solar-radiation data can be used to model annual PV electricity yield before you compare grants, export income, battery storage or installer quotes.
The simple formula
Annual solar output is estimated by multiplying your county’s annual yield by your solar system size.
For example, the Dublin representative point has an estimated yield of 981 kWh/kWp/year. An illustrative 4 kWp system at the same location and settings is therefore estimated at about 3,924 kWh per year.
Example output estimates
- 4 kWp in Wexford: 1,046 × 4 = 4,184 kWh/year.
- 4 kWp in Dublin: 981 × 4 = 3,924 kWh/year.
- 4 kWp in Donegal: 817 × 4 = 3,268 kWh/year.
- 10 kWp in Wexford: 1,046 × 10 = 10,460 kWh/year.
Solar Irradiance Ireland by County: 26 Representative Points Ranked
This table ranks one representative coordinate in each Irish county by estimated annual solar PV yield using PVGIS 5.3/SARAH3 data. The 4 kWp column is an illustrative output estimate, not a county-wide measurement or site survey.
| Rank | County | kWh/kWp/year | vs 26-point average | Illustrative 4 kWp output | Region |
|---|---|---|---|---|---|
| 1 | Wexford | 1,046 | +12.7% | 4,184 kWh | Southeast |
| 2 | Waterford | 988 | +6.5% | 3,952 kWh | Southeast |
| 3 | Dublin | 981 | +5.7% | 3,924 kWh | East |
| 4 | Louth | 979 | +5.5% | 3,916 kWh | Northeast |
| 5 | Cork | 972 | +4.7% | 3,888 kWh | South |
| 6 | Kilkenny | 955 | +2.9% | 3,820 kWh | Southeast |
| 7 | Meath | 947 | +2.0% | 3,788 kWh | East |
| 8 | Laois | 942 | +1.5% | 3,768 kWh | Midlands |
| 9 | Galway | 941 | +1.4% | 3,764 kWh | West |
| 10 | Tipperary | 941 | +1.4% | 3,764 kWh | South Midlands |
| 11 | Carlow | 940 | +1.3% | 3,760 kWh | Southeast |
| 12 | Kildare | 940 | +1.3% | 3,760 kWh | East |
| 13 | Offaly | 934 | +0.6% | 3,736 kWh | Midlands |
| 14 | Westmeath | 932 | +0.4% | 3,728 kWh | Midlands |
| 15 | Clare | 931 | +0.3% | 3,724 kWh | West |
| 16 | Roscommon | 923 | -0.5% | 3,692 kWh | West |
| 17 | Wicklow | 917 | -1.2% | 3,668 kWh | East |
| 18 | Limerick | 916 | -1.3% | 3,664 kWh | Midwest |
| 19 | Kerry | 909 | -2.0% | 3,636 kWh | Southwest |
| 20 | Longford | 909 | -2.0% | 3,636 kWh | Midlands |
| 21 | Monaghan | 895 | -3.6% | 3,580 kWh | North |
| 22 | Cavan | 889 | -4.2% | 3,556 kWh | North Midlands |
| 23 | Mayo | 879 | -5.3% | 3,516 kWh | West |
| 24 | Sligo | 868 | -6.5% | 3,472 kWh | Northwest |
| 25 | Leitrim | 840 | -9.5% | 3,360 kWh | Northwest |
| 26 | Donegal | 817 | -12.0% | 3,268 kWh | Northwest |
Checked 20 August 2026 using the PVGIS 5.3 API and PVGIS-SARAH3 (2005–2023), with one representative coordinate per county. Settings: 1 kWp, crystalline silicon original/default model, free-standing fixed mount, 35° tilt, south-facing azimuth, calculated horizon and 14% system losses. Actual roof output varies with location, pitch, orientation, shading, equipment and year-to-year weather.
Solar Irradiance by County
See how much solar energy your county receives compared to the rest of Ireland.
How We Calculated the Solar PV Yield Estimates
This page uses the PVGIS 5.3 grid-connected PV model and PVGIS-SARAH3 data from the European Commission Joint Research Centre. The figures are estimated PV electricity yield in kWh/kWp/year, not measured solar irradiance in kWh/m².
PVGIS settings used
- PVGIS version: 5.3.
- Radiation database: PVGIS-SARAH3, 2005–2023.
- System size: 1 kWp.
- Technology: crystalline silicon, original/default PVGIS model.
- Mounting: free-standing fixed system.
- Tilt: 35° from horizontal.
- Orientation: south-facing, azimuth 0°.
- Calculated horizon: enabled.
- System losses: 14%.
County methodology
- One fixed representative coordinate is used for each of the 26 counties.
- Kerry is centred on Tralee for consistency with the representative-location approach.
- The 26-point average is a simple mean, not an area-weighted national average.
- Values are rounded to the nearest whole kWh/kWp/year.
- These figures compare locations consistently; they do not represent every roof within a county.
Solar Yield by Region in Ireland
The representative-point estimates vary across Ireland, but the difference is not large enough to make solar unviable in lower-yield locations. The strongest results in this standardised comparison are concentrated in the Southeast and East Coast.
Southeast
The Wexford, Waterford, Kilkenny and Carlow representative points average about 982 kWh/kWp, roughly 6% above the 26-point average.
East Coast
The Dublin, Louth, Meath, Kildare and Wicklow representative points average about 953 kWh/kWp.
South and Southwest
The Cork and Kerry representative points average about 941 kWh/kWp, close to the 26-point average.
Midlands
The Tipperary, Laois, Offaly, Westmeath and Longford points sit close to the 26-point average, with values around the low-to-mid 900s.
West and Midwest
Galway, Clare, Limerick, Roscommon and Mayo vary by county, but most remain within a practical range for domestic solar PV.
North and Northwest
The Donegal, Sligo, Leitrim, Cavan and Monaghan points rank lower, but even the lowest estimate still represents meaningful annual solar generation.
Turn County Solar Yield into a Savings Estimate
Your county yield is only the starting point. Real payback also depends on your roof, electricity use, SEAI grant eligibility, export rate and whether you add battery storage.
Solar Irradiance Ireland FAQs
Which Irish county has the highest solar irradiance?
The Wexford representative point ranks highest in this standardised PVGIS comparison, with an estimated annual PV yield of 1,046 kWh/kWp/year. This is a point estimate of PV electricity output, not a county-wide measurement of solar irradiance.
What is Ireland’s average solar PV yield in kWh/kWp?
The simple average of the 26 representative-point estimates is 928 kWh/kWp/year. An illustrative 4 kWp system at that modelled yield would produce about 3,712 kWh per year. This is not an area-weighted national average.
What does kWh/kWp/year mean for solar panels?
kWh/kWp/year means the annual electricity output produced by each kilowatt-peak of installed solar panels. To estimate annual output, multiply your county yield by your system size. For example, 981 kWh/kWp in Dublin multiplied by a 4 kWp system gives about 3,924 kWh/year.
Does solar work in the West and Northwest of Ireland?
Yes. The western and northwestern representative points generally show lower PV yield than the Southeast and East Coast, but solar can still produce meaningful annual electricity. Roof direction, pitch and shading affect output, while usage patterns, export rates, batteries and grants affect financial returns.
Is PVGIS-SARAH3 the same as a quote from an installer?
No. PVGIS 5.3/SARAH3 provides a standardised modelled yield estimate for a chosen coordinate and system configuration. An installer assessment should also account for your exact roof pitch, orientation, shading, usable area, equipment and electrical setup.
How do I calculate solar savings from PV yield data?
First estimate annual output from the representative yield and your proposed system size. Then consider self-consumption, exported electricity, supplier export rates, battery behaviour and any SEAI grant support. Use the Solar Decision Tool for a fuller savings and payback estimate.