The Eco Hub

Ireland's best counties for solar What power you can get based on your location in Ireland

Solar panels are an effective means of clean energy production, wherever you are in Ireland. But there's no doubt about it — the performance of solar panels in Ireland can vary significantly depending on your location. On this page, we've ranked all the Irish counties from best to worst, including calculating the difference in output from identical systems. Use this page to find out what kind of solar performance you can expect based on where you live.

Location and solar efficiency

When it comes to solar panels in Ireland, there's no doubt about it — location does have an effect. Other individual factors may be more significant, such as roof orientation, pitch or shading. But location is something lots of people ask us about here at PureVolt Solar, and that's why we have collated the research on this page.

Roughly speaking, the further south and east you live, the more efficient your solar panels will be (all other things being equal). So the sunny southeast lives up to its name, with solar installations there consistently leading the pack. For example, solar panels installed in Wexford produce 9.2% more than the national average. By contrast, solar arrays in County Donegal would produce the lowest output, at 7.6% below the national average.

On this page, you can see the annual solar generation for identical systems across Ireland, and how that compares to the national average of 884 kWh / kWp. As you will see, the difference is significant but still small enough that solar panels are likely to be a worthwhile investment, wherever you live in Ireland. For more information check out our guide to the cost of solar panels Ireland.

The counties of Ireland Ranked from best to worst for solar output

As you might expect, the further you go to the south and east, the more power output you can get from your solar panels in Ireland. If you live in Wexford, you can expect your solar panels to be 18.1% more productive than an equivalent solar array in Donegal.

By county: Irish annual solar generation per kWp of panels

County solar comparison in numbers

County Annual Solar Generation per kWp of panels Based on south-facing roof, 30° pitch Compared to national average 884 kWh / kWp
County Wexford965 kWh +9.2%
County Waterford949 kWh +7.4%
County Wicklow947 kWh +7.1%
County Dublin915 kWh +3.5%
County Carlow911 kWh +3%
County Cork907 kWh +2.6%
County Kilkenny905 kWh +2.3%
County Kerry896 kWh +1.3%
County Clare888 kWh +0.5%
County Laois888 kWh +0.4%
County Kildare885 kWh +0.1%
County Meath885 kWh +0.1%
County Galway886 kWh +0.2%
County Tipperary884 kWh -0.1%
County Louth881 kWh -0.3%
County Offaly881 kWh -0.3%
County Westmeath871 kWh -1.5%
County Limerick869 kWh -1.7%
County Roscommon867 kWh -2%
County Longford854 kWh -3.3%
County Sligo847 kWh -4.2%
County Leitrim842 kWh -4.7%
County Mayo841 kWh -4.9%
County Monaghan841 kWh -4.9%
County Cavan841 kWh -4.8%
County Donegal817 kWh -7.6%

Why are the counties so different?

Three main factors play into the regional variations in solar power output across Ireland: latitude, altitude, and local climate.

Latitude

How far north or south you are has a significant effect, with further south being more productive. This is because counties in the south of Ireland receive more direct sunlight and longer daylight hours throughout the year, which boosts solar energy generation potential compared to counties further north.

Local climate

Local climate is surprisingly important. Cloud cover is the main driver here that brings variety across the country. Yes, temperature has an effect (cooler is better), but again there's not enough difference here in Ireland for that to be significant.

Solar Installations in Dublin (3.5% above the national average) and Wicklow (7.1% above the national average) are great examples of how their sunnier weather gives solar panels installed in those counties an extra boost.

They outperform counties like Cork (2.6% above national average) and Kerry (1.3% above national average), despite Dublin and Wicklow being further north.

The datasets used in such calculations have huge amounts of historical data, using things like satellite records of cloud cover, to try and predict the likely solar energy available at every location across the country. It's never spot on, but still, they are very impressive tools that are available and have a surprising amount of localisation built in.

Altitude

Altitude does have some effect. But, here in Ireland, the variation in altitude isn't significant enough to have a noticeable impact on solar output.

What do the numbers mean, exactly?

There are a lot of numbers above, as well as some assumptions. Let's look at them one by one to see what they all mean.

kWp (kilowatt-peak) of panels

kWp is a measurement of the maximum theoretical output of an array of solar panels. Imagine you took a set of panels, and put them in perfect lab conditions. The power they would produce in those ideal conditions is the kWp rating.

This is the value most solar installations are quoted in. When someone says "I've a quote for a 4kW system", what that means is a 4 kWp system. Equally, if someone says "I'm getting 440w panels installed", it means those panels would produce 440w under ideal lab conditions.

In the real world here in Ireland we never quite get those perfect conditions. But, in the middle of a blue sky summer day, you can get to 90%-95% of this theoretical maximum.

Annual Solar Generation per kWp of panels

Here we are talking about the number of units of electricity you'd get per year from a 1kWp installation on your roof. 1 unit of electricity = 1 kWh (kilowatt-hour) of electricity.

How we did these calculations

Here are the assumptions we made to make sure we were comparing all the counties like for like.

  • Roof facing due south
  • Roof angle: 30 ° (which is typical for an average house)
  • No shading
  • We picked one representative town in each county as the exact location
More information

One of our favorite resources is the Global Solar Atlas, which provides highly detailed information on solar irradiance levels and much more for every inch of the country. For more information, visit Global Solar Atlas - Ireland

PureVolt Solar Panels Ireland

About us

This is a free resource commissioned and funded by PureVolt Solar Ireland. The Eco Hub has been developed by our green energy experts in collaboration with the engineers, scientists, and data specialists from our sister company SquareFish .

On pages like this one, we try to share our passion and motivations for a greener Ireland by presenting clear, factual information without getting on a soapbox. We hope this page is useful for you. Please get in touch to let us know if we can make it better :)