Over the next decade, decision makers in Ireland will need to balance a range of trends and policy ambitions that have strong implications for the power sector. Ireland has set a range of policy goals spanning the next decade, from improving energy security by reducing its reliance on imported fossil fuels, to meeting its climate targets, expanding its housing stock, and supporting the growth of digital infrastructure such as data centres. These ambitions all have strong links to the country's power sector, with implications for electricity demand, infrastructure and supply. In this context, it will be key for Ireland to consolidate its wider strategic vision and integrate it with longer-term power system planning. This will help set priorities and guide market and system development, while allowing potential trade-offs to be proactively identified and managed, where possible.

Ireland has a long track record of transforming its power system while managing strong electricity demand growth. In 2024, Ireland supplied about one-third of its electricity from wind, four times the global average and second only to Denmark among countries with gigawatt-scale systems. That made wind the second largest source of electricity in Ireland behind natural gas, which had a share of more than 40%. This achievement – the result of pioneering initiatives to integrate renewables – is outstanding for a relatively small, island-based grid, and it was managed as annual electricity demand grew by about 20% between 2015 and 2023. Ireland is scaling infrastructure and modernising operations further to reach its goals of 80% renewable electricity by 2030 and running a system almost entirely from wind, solar, storage and imports by 2035, while managing growing electricity demand from the housing, data centre, heat and transport sectors.

To support decision makers as they plan for the future, this report introduces a pathway that explores what would be required to maintain electricity security while advancing towards Ireland’s ambitions. This Adapted Transition Pathway was developed with EirGrid, which manages Ireland's transmission grid. It combines a range of existing projections and scenarios based on Ireland’s sectoral ambitions, exploring how the supply side could transform to meet a potential near doubling of electricity demand by 2035, driven by growth in the housing and data centre sectors and efforts to accelerate the electrification of heat and transport. This pathway illustrates how various ambitions align around the power sector, while highlighting the potential trade-offs that may need to be managed between energy security, decarbonisation and affordability.

The properly managed electrification of heating and transport would sharply reduce Ireland’s reliance on imported fossil fuels. Replacing oil- and gas-based boilers and vehicles with electric alternatives could cut direct fossil fuel imports by 38% and lower annual import bills by EUR 2.8 billion. This would support significant reductions in Ireland’s reliance on imported fossil fuels, which currently account for 80% of total national energy supply. However, significant upfront costs, high electricity prices compared with fossil fuels, and grid capacity constraints remain barriers. Integrating heat electrification with thermal storage and incentivising smart charging will be essential to align new demand with renewable generation and reduce strains on the power system.

Meeting rising electricity demand in the Adapted Transition Pathway would require faster deployment of renewables. This pathway sees electricity demand nearly doubling to 2035. From 2023, electricity demand from the residential and data centre sectors would each grow by about 7 terawatt-hours (TWh) to 2035. However, without faster progress, the 80% renewables target for 2030 would not be met, increasing dependency on electricity imports and prolonging reliance on natural gas-fired generation, which set wholesale electricity prices 80% of the time in 2022 and currently accounts for 60% of national natural gas consumption.

Higher renewable penetration would shift the role of thermal generation to a security backup. In the Adapted Transition Pathway, gas-fired plants would continue to play a role in maintaining electricity security, though they shift from delivering the bulk of electricity supply to providing flexibility and helping to meet peak demand, including during periods of low renewable output. This would result in the utilisation rate (or capacity factor) of gas-fired plants falling from about 46% in 2023 to 12% in 2035. This lower utilisation would make it less economically viable to keep all units available, since operators would need to cover fixed costs despite more limited running hours. While gas-fired generation would continue to support electricity security, ongoing reliance on imported natural gas would continue to expose the power system to potential supply disruptions and the volatility of fossil fuel markets. To manage this trade-off, Ireland will need financing mechanisms that can help guarantee that there is sufficient thermal capacity to ensure electricity security, but investments do not exceed what is needed.

Ireland should strategically assess and choose the composition of its electricity supply portfolio, with potential demand trajectories in mind. In the Adapted Transition Pathway, Ireland would reach a peak residual demand, or a measure of total demand minus wind and solar output, of 10 gigawatts (GW) by 2035. To cover this demand securely under that pathway, Ireland would need to develop a portfolio that reaches 16 GW of dispatchable capacity (including thermal generation, storage and interconnectors). This would require ambitious development of new battery capacity and higher electricity imports, alongside thermal plants that would operate mainly as backup power supply. Depending on how demand and the supply mix evolve under different policy pathways, revising capacity requirements often will be crucial for prudent planning, along with continued efforts to reduce reliance on imported fossil fuels.

Delivering on demand and supply ambitions while strengthening resilience depends on timely grid investment. In the Adapted Transition Pathway, transmission and distribution grids must manage rapid demand growth from households, data centres, heat and transport, while also integrating more renewables. Ireland is ramping up grid investments, planning on a record EUR 10‑14 billion between 2026 and 2030, up from EUR 5 billion between 2021 and 2025. But long lead times and permitting challenges remain key barriers. Grid investments should include a focus on resilience, particularly in rural areas, which suffered the longest outages due to Storm Éowyn in 2025. Additionally, new cross-border interconnectors, on top of those already planned, should be considered to further diversify supply.

Operating a system dominated by wind and solar, batteries and interconnectors will require new approaches to stability and flexibility. In the Adapted Transition Pathway, renewables would supply 88% of electricity by 2035, supported by expansion of energy storage and interconnectors. Converter-connected technologies – including wind, solar and batteries – would transform how the system operates, and which resources deliver essential power system services. By 2035, inertia, ramping and other services in the Adapted Transition Pathway would be provided mainly by batteries, demand response and synchronous condensers at levels not yet observed internationally. This highlights the need for further studies and continued modernisation of system operations to ensure system security.

To deliver on Ireland’s energy, climate and socio-economic goals, including the decarbonisation of its power sector while maintaining electricity security and affordability, this report makes a series of recommendations. These include:

Establish a cross-sectoral energy security strategy for the 2030s. The Adapted Transition Pathway illustrates how ambitious goals across housing, data centres, transport and heat converge around the power sector, driving rapid growth in electricity demand. Ireland would benefit from an integrated strategy to align these efforts with its decarbonisation and energy security objectives. A unified strategy would consolidate sectoral ambitions, assess trade-offs, and set clear priorities and milestones for developing power system infrastructure, markets and operations. It would also allow for an infrastructure needs assessment conducted in tandem with an in-depth study of power system adequacy to evaluate electricity security under the envisioned pathway.

Accelerate the delivery of grid infrastructure alongside additional electricity supply and flexibility resources. The Adapted Transition Pathway highlights the scale of new infrastructure needed to deliver on multiple ambitions, which would result in both high demand growth and renewable penetration in power supply. Major investment plans are in place, yet the challenge will be ensuring timely delivery given long lead times. Anticipatory and flexible investment must be complemented by faster permitting, proactive supply chain management, as well as incentives and connection requirements for higher demand flexibility to ensure grids, generation and flexibility resources are ready when needed.

Enable secure operations under high renewable penetration. As the power system evolves and flexible demand comes online, Ireland should translate the technical requirements for ensuring stability and flexibility into concrete policy and operational measures. This entails building on EirGrid’s groundwork with SONI, Northern Ireland's electricity transmission system operator, upgrading operational frameworks, investing in advanced modelling and automation, and continuing to update grid codes and system services arrangements. Strengthened cybersecurity and close collaboration among operators, regulators and policymakers is needed to ensure that Ireland’s operational capabilities evolve fast enough to safeguard security as the share of renewable electricity evolves.

Advance workforce skills, strengthen partnerships and facilitate electrification. These areas will be key to the success of Ireland’s policy goals. Training and reskilling programmes and knowledge sharing would prepare institutions to manage a more complex power system. Meanwhile, stronger regional and global partnerships will boost innovation, accelerate infrastructure delivery, and strengthen key supply chains to procure technology, infrastructure and energy commodities. At the same time, tackling barriers to the electrification of heat and transport – such as by addressing cost gaps by considering tariff reforms and instituting targeted policies to overcome infrastructure constraints – would speed up Ireland’s transition while maintaining energy security.

With a clear vision and co-ordinated action, Ireland can continue to be a global example for managing secure energy transitions. Building on its success in wind integration and system innovation, Ireland can show how a relatively small, island-based system can operate securely with very high shares of renewables. By doing so, it can continue to advance its own socio-economic and climate goals while offering lessons for other countries pursuing ambitious transitions.