Why Integrating More Solar Farms in Ireland Matters
As countries are trying to replace fossil fuels with renewable energy, they are hitting a major problem: sometimes the sun does not shine, and the wind does not blow at the same time. These periods of low renewable generation, sometimes named "renewable energy droughts" or "Dunkleflaute", could leave the power grid vulnerable during critical times.
These droughts are not rare weather events. They happen regularly, and power system operators need to plan for them carefully. The more Ireland depends on wind and solar, the more crucial it becomes to predict when these droughts will occur, how long they will last, and how severe they might get.
What We Did
To understand renewable energy droughts better, we used 45 years of historical weather data to model how much wind and solar power would have been generated across Ireland if a certain amount of wind and solar farms were installed. Energy scientists typically use general models built from data across all of Europe to answer these types of questions.
But we wondered: how different would Ireland's results be if we used a model specifically tailored to Irish weather and using actual farm locations? We compared both approaches and then analysed two scenarios: Ireland's current situation (where wind power makes up 91% of renewable capacity and solar power just 9%, as shown in the image below), and a more balanced future scenario (with roughly equal wind and solar capacity).
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| Map of wind (green) and solar (orange) farms in the Republic of Ireland and Northern Ireland. Most of the wind farms are located in the western part of the country, whereas solar farms appear more on the Eastern side. The size of the dots represent the maximum amount of electricity that can be generated by each farm. |
What we found
Our tailored Irish model revealed significantly more renewable energy droughts than the generic European model. This gap reveals a critical point: if power planners use the wrong model, they could seriously underestimate how vulnerable the grid is during drought periods.
When we modelled a transition to a more balanced energy mix with much more solar capacity, the results were striking. The number of renewable energy drought events dropped by roughly 50%. A five-day drought that occurs every six months under today's wind-heavy system would happen only once every four years in a more diversified system.
This improvement happens because wind and solar are naturally complementary. In Ireland and much of Northern Europe, wind tends to be stronger during winter, while solar generation peaks during summer. By mixing both sources, the energy system produces more consistent power throughout the year.
If you are interested in understanding more about this, feel free to read the article available online.
