Solar Ireland: Scaling fast, with significant room to grow

Last year, solar became a core component of Ireland’s electricity system. With over 2.1 GW now online, Solar Ireland CEO RONAN POWER examines the “three realities” driving this rapid expansion and explains why smarter integration—not just more installation—is the key to future-proofing Ireland’s built environment.

Ireland’s solar sector had a defining year in 2025. Not because the challenges disappeared, but because solar moved decisively from an emerging option to proven infrastructure across homes, farms, businesses and utility-scale projects.

National solar capacity passed 2 GW

National solar capacity passed 2 GW in 2025, reaching over 2.1 GW by November, while rooftop solar exceeded 1 GW in December, distributed across more than 170,000 rooftops nationwide.

These milestones confirm that solar is now a core component of Ireland’s electricity system, with growing relevance for how buildings are designed, operated and future-proofed.

For the building services sector, particularly, this shift matters. Solar is no longer confined to early adopters or demonstration projects. It is increasingly being incorporated into energy strategies, cost management approaches, and carbon-reduction plans for buildings of all sizes, while still at a relatively early stage of national deployment.

Scale of Solar 2025 report

Solar in Ireland is no longer a niche technology. It is infrastructure, and it is delivering at scale.

Solar Ireland’s ‘Scale of Solar 2025’ report, published mid-year, highlighted strong growth across micro-generation, commercial rooftops, auto-production and solar farms nationwide. The report estimated 2025 solar generation at approximately 1,558,570 MWh, enough to meet the annual electricity needs of more than 370,000 homes, alongside associated emissions savings of around 395,877 tonnes of CO2.

At the same time, this pace of deployment has brought the next set of challenges into sharper focus, particularly around grid capacity, skills availability, planning timelines and the policy frameworks needed to support sustained, high-quality delivery as volumes continue to rise.

Three important realities

Behind the headline figures, 2025 reinforced three crucial realities.

First, rooftop solar is moving beyond early adoption. Uptake accelerated across homes, farms, schools and businesses, driven by rising energy awareness, improving economics and greater familiarity with the technology. The scale now being delivered reflects not just demand, but the gradual build-out of design, installation, engineering and certification capability across the built environment.

Second, large energy users are increasingly treating solar as a core operational consideration. Commercial rooftops, auto-production systems and corporate power purchase agreements are being deployed to address cost volatility, decarbonisation targets and resilience. These approaches reduce peak demand, lower operational emissions, and bring generation closer to where electricity is used, an increasingly important consideration for system efficiency.

Third, integration is now as important as installation. As solar penetration increases, its value depends more on how well it is connected, managed and complemented by storage and flexible demand. This is where building services professionals play a central role, through energy management systems, smart controls, EV charging optimisation, thermal storage and battery integration.

A fast-growing sector, still building depth

Ireland’s solar market is expanding quickly, but it remains at a relatively early stage compared with where it needs to be by 2030 and beyond. Grid processes, connection timelines, skills availability and planning capacity remain defining constraints. These are not unique to solar, but solar’s speed of deployment makes them particularly visible.

This context matters as Ireland aligns with new EU frameworks, including the Net-Zero Industry Act, revised renewable permitting requirements, and the evolving Energy Performance of Buildings Directive (EPBD). These initiatives rightly raise expectations around sustainability, resilience and system outcomes. At the same time, they underline why targeted supports for households and smaller businesses continue to play an essential role in enabling participation, building supply-chain capacity and supporting quality delivery.

NZIA, auctions and the next phase of delivery

One of the most important policy conversations now underway concerns how renewable support auctions evolve under the Net-Zero Industry Act (NZIA) and related EU requirements.

Future auctions will increasingly move beyond price alone to include non-price criteria such as sustainability, supply-chain resilience and innovation. This direction is broadly supported across the sector, but implementation will be critical. Criteria must be clear, measurable and proportionate, strengthening outcomes without introducing unnecessary complexity, cost or delivery risk at a time when scale-up remains essential.

For industry, the objective is not to slow progress, but to ensure Ireland continues to deliver renewable capacity efficiently while building the depth and resilience needed for long-term delivery.

Looking ahead

If 2025 was about demonstrating scale, 2026 must be about enabling the next phase of growth.

Key priorities for the year ahead include faster, more predictable planning and permitting, grid frameworks that can keep pace with deployment, clarity on hybrid projects, storage, and private wires, and continued support for rooftop solar as part of Ireland’s evolving building stock.

These themes will also shape Solar Ireland’s 2026 Annual Conference, titled ‘Energising Life – Decarbonising How We Live’, which will focus on integration, system readiness, and the practical role solar now plays across buildings, infrastructure, and everyday energy use.

Solar Ireland will also place increased emphasis on public information and engagement. As deployment expands, clear, evidence-based communication will be essential to address misconceptions and build confidence among communities, energy users and decision-makers.

A role for the building services sector

Building services professionals are central to the next stage of Ireland’s solar journey. The challenge ahead is not simply to install more capacity, but to integrate solar effectively, ensuring buildings contribute to a resilient, flexible and efficient electricity system.

Solar in Ireland is scaling rapidly, but there remains substantial room to grow. With the right policy frameworks, skills development and system investment, solar can continue to expand in a way that delivers long-term value for Ireland’s built environment and energy system.