Solar Output Across Ireland
Solar panel output depends on solar irradiance (how much sunlight reaches your roof). Ireland receives between 900 and 1,100 kWh/m² of solar irradiance per year, depending on location. The south-east gets the most, the north-west the least, but the variation is surprisingly small.
For a typical 4 kWp system, here's what you can expect by region:
| Region | Representative Counties | Annual Output (4kWp) | Relative Performance |
|---|---|---|---|
| South-east | Wexford, Waterford, Kilkenny | 3,800–4,200 kWh | 100% (baseline) |
| South | Cork, Kerry, Tipperary | 3,600–4,000 kWh | 95% |
| East | Dublin, Wicklow, Louth, Meath | 3,500–3,900 kWh | 93% |
| Midlands | Laois, Offaly, Westmeath, Longford | 3,400–3,800 kWh | 90% |
| West | Galway, Clare, Limerick | 3,300–3,700 kWh | 88% |
| North-west | Donegal, Sligo, Leitrim, Mayo | 3,100–3,500 kWh | 85% |
The key takeaway: the difference between the best and worst locations is about 15%. Solar panels are financially viable in every county in Ireland.
What Matters More Than Location
1. Roof orientation
A south-facing roof produces 100% of potential output. East or west-facing produces about 85%. South-east or south-west is nearly as good as due south. Even north-facing roofs produce 60–70%, though this is less ideal.
2. Roof pitch
The ideal angle for solar panels in Ireland is 30–35° from horizontal. Steeper roofs (common on older Irish houses) still work well. Flat roofs need panels mounted on frames at an angle.
3. Shading
Even partial shading from trees, chimneys, or neighbouring buildings can significantly reduce output. Your installer should assess shading patterns throughout the year.
4. System size and quality
A well-designed system with quality components outperforms a poorly designed system in the same location. Your installer's experience matters more than your county.
What This Means for Savings
Using current electricity prices (34c/kWh import, 19c/kWh export), a 4 kWp system saves approximately:
| Region | Annual Savings | Payback (after €1,800 grant) |
|---|---|---|
| South-east | €1,100–1,400 | 4–6 years |
| South / East | €1,000–1,300 | 5–6 years |
| Midlands / West | €900–1,200 | 5–7 years |
| North-west | €850–1,100 | 6–7 years |
A BER is the starting point for most energy upgrades and grant applications. Homerating.ie has been assessing Irish homes since 2009, with fast turnaround in Dublin and nationwide coverage. Book a BER with Homerating.ie →
Frequently Asked Questions
Yes. Even in the cloudiest parts of Ireland, solar panels produce enough electricity to give a strong financial return. The difference between the sunniest and cloudiest counties is only about 15%.
Roof orientation and shading matter significantly more than county. A south-facing roof in Donegal will outperform a north-facing roof in Wexford. Get a site-specific assessment from your installer.