Solar steps into spotlight in Ireland’s energy transition

Mullingar Sustainable Energy Community

Earlier this summer (on May 25), during a series of particularly bright and sunny days, solar power supplied up to 29% (1,330MW) of Ireland’s electricity generation at peak times. For many, that may have come as a surprise. Solar has long been seen as a marginal contributor in Ireland, a country more often associated with cloud cover than clear skies, but the milestone is a reminder of how quickly things are changing.

Only a few years ago, solar barely registered in Ireland’s energy mix. Grid connections were slow to develop and the technology was often dismissed as unsuitable for Irish conditions. But today, solar is visible on rooftops and in fields across the country, and is also making a meaningful contribution to the national grid.

This rapid growth has been driven by a combination of falling technology costs and improved policy supports. Solar panels are now more efficient and more affordable than ever before. At the same time, the availability of grants from the SEAI for rooftop solar has enabled households and farmers to become active participants in energy production.

For Mullingar, the shift presents an opportunity. Solar energy is particularly well suited to local, decentralised generation. Rooftops, farm buildings, schools and community buildings can all play a role. The benefits are environmental and economic, driving down the costs of electricity and building resilience against rising energy costs.

The significance of solar’s recent performance goes beyond its growth alone, as it also highlights a reality in Ireland’s renewable energy journey: we cannot depend on wind power alone.

Wind has been the backbone of Ireland’s renewables and remains essential for our future mix, but wind is inherently variable, often forcing a reliance on expensive gas and interconnector imports during lulls.

Solar provides a counter-balance through seasonal and daily variance:

• Seasonal Balance: Wind output peaks in winter, while solar generation reaches its maximum during long summer days, smoothing out annual supply.

• Weather Complementarity: Calm, high-pressure conditions that lower wind speeds frequently bring clear skies, allowing solar to step in when wind dips.

• Dependability: Crucially, solar continues to yield positive contributions even on cloudy days via diffuse daylight, avoiding total drop-offs.

• Peak Demand Alignment: Beyond weather, solar naturally delivers power during the day, aligning closely with peak daytime electricity usage.

The sunny days this summer when solar contributed nearly a third of electricity demand at times demonstrate how solar can step in when wind output dips, helping to stabilise the system and reduce reliance on carbon-intensive generation. This complementary mix between wind and solar will be vital to stabilise the grid, reduce electricity prices and decarbonise Ireland’s electricity system.

Looking ahead, the challenge is to build on the momentum. Expanding solar capacity, both at utility scale and at community level, will be crucial. But we also need to continue to invest in grid infrastructure and energy storage, which are necessary to make the most of variable renewable generation.

The Mullingar Sustainable Energy Community (SEC) is pursuing the development of a community-owned solar farm on the former landfill site in Marlinstown. Being community-owned, profits will not disappear into a private company, and can be reinvested in retrofitting projects in the town to combat fuel poverty.

Progress has been slow due largely to the fact that community-based solar projects are treated exactly the same large, private commercial projects. That is an immediate barrier to the viability of community-owned projects which struggle to get off the ground without the equity of private companies.

Such community-led initiatives can help accelerate the uptake of solar, raise awareness, and ensure that the benefits are shared locally.

In July, representatives from the Mullingar SEC visited Lehinch Solar Farm near Clara in Offaly. They were hosted by the landowners, farmers David and Stephanie Connor, and the visit was facilitated by Shannon Energy. The visit demonstrated what can be achieved on a midlands site.

The lesson from this summer is clear. Solar is no longer a niche technology in Ireland; it is a growing and valuable part of the energy system. And when combined with wind, it offers a more resilient and sustainable path forward.

The transition to renewable energy is not about choosing one technology over another; it is about building a diverse and complementary system. The recent contribution of solar shows that Ireland is moving in that direction, and that communities like Mullingar can be at the heart of it.

Mullingar Sustainable Energy Community