EirGrid, which is responsible for balancing electricity supply and demand every minute of the day from the National Control Centre, while also strategically planning for Ireland’s long-term electricity needs, has released its annual All-Island Resource Adequacy Assessment, which looks at the balance between electricity demand and supply in Ireland over 10 years.
The assessment looks at demand (what Ireland needs), generation (what can supply the demand) and adequacy (the potential gap between the two).
Increasing tightness between supply and demand
Since 2016, EirGrid has warned of an increasing tightness between supply and demand. In this context, the objective of the report is to allow industry, government, regulators and other stakeholders to facilitate the transition to renewable energy, supporting social and economic growth into the future, meeting future demand, while ensuring the secure and resilient operation of the electricity system.
Each year, EirGrid ‘freezes’ the data on which the calculations are measured, to ensure an accurate assessment is provided. The freeze date for demand data for this report was June 30, 2025.
Demand (what Ireland needs)
Predicting future electricity demand is a complex task. EirGrid looks at a range of scenarios so that it can understand the possible outcomes depending on a range of influential factors. These variables include aspects such as temperature, the economy, contracted large energy user growth, energy efficiency as well as the electrification of heat and transport.
These inform the three demand scenarios for Ireland which are median demand, low demand and high demand. The median secure demand scenario is EirGrid’s best estimate of what might happen in the future.
Looking out to 2030 and beyond, the median scenario shows that electricity demand is set to continue to increase as consumers use electricity in new ways, with slower but sustained growth then out to 2035.
Government policies are expected to help guide us away from fossil fuels toward alternative heating methods, such as electric heat pumps, and cleaner modes of transport, such as electric vehicles.
Generation (what can supply this demand)
Over the next 10 years, the sources of electricity supply will continue to change as the country transitions to a predominantly renewable power system. EirGrid expects new generation capacity will be delivered through the SEM capacity auctions and additional renewable capacity will be introduced through the Renewable Energy Support Scheme (RESS) and Offshore RESS auctions.
Adequacy (gap between demand and generation)
In the report, adequacy is assessed against a standard called the ‘Reliability Standard’. This standard is set by the Department of Climate, Energy and the Environment (DCEE) working with our regulator, the Commission for Regulation of Utilities (CRU).
The Reliability Standard is expressed using Loss of Load Expectation (LOLE), which is the number of hours per year that a country’s electricity production is not expected to meet its demand. It is important to note that the LOLE measurement does not necessarily mean that electricity consumers will be without supply for any period. The output from this assessment is a forecast of LOLE and an indication of whether or not the system requires additional capacity to operate securely.
The Reliability Standard for Ireland is three hours LOLE.
The report also presents different scenarios when assessing adequacy, looking at two different scenarios, one based on normal operating conditions (base scenario) and one factoring in more challenging conditions (secure scenario).
EirGrid considers the secure assessment is most prudent and should be considered as the central scenario for adequacy assessments, noting that capacity market auctions will procure new capacity if required to address capacity shortfalls in the medium to long term.
According to the report:
* From 2026 to 2028, both assessments (base and secure) show the system is outside of the Reliability Standard of three hours, meaning additional capacity is required;
* From 2029, the base assessment is within the Reliability Standard, meaning there is sufficient capacity to operate the system under normal conditions. The secure (more challenging) assessment, however, remains outside of standard indicating around 200MW is required increasing to over 400 MW in 2034 to ensure we can continue to balance supply and demand under more challenging conditions.
The report also notes that as part of these actions from the CRU-led Security of Supply programme, the CRU directed EirGrid to procure Temporary Emergency Generation (TEG) and Retain Existing Units (REU) at Moneypoint. The TEG and Moneypoint (REU) units are available as out of market measures to provide critical back-up generation and will be called upon in the event of a shortfall in market-based capacity and where alerts on the system are likely.
While not included in the scenarios, due to the fact that they are temporary arrangements, EirGrid notes that they have been critical to improve the adequacy position for the country and will continue to be during the potentially challenging years identified.
Transition to a renewable-led transmission system
Marc Senouci, head of power system insights and research design authority at EirGrid, said: “As society consumes electricity in different ways, and as we transition to a renewable-led transmission system, the electricity industry will need to identify new ways to meet growing demand for energy.
“As the landscape of demand and generation supply changes, and as electricity demand increases, government policy will help guide the transition, but a coordinated effort to manage both the volume and type of new capacity will be needed.
“In addition, it’s crucial that the capacity market delivers new capacity efficiently, and the type and volume of capacity needed to underpin the energy transition.
“EirGrid will continue to proactively engage with the Department of Climate, Energy and the Environment (DCEE), the Commission for Regulation of Utilities (CRU) and other relevant stakeholders to provide timely assessments, analysis, and options for operational mitigations.
“In the wider context, EirGrid is currently progressing the most ambitious programme of work ever taken on the transmission system in Ireland. This includes connecting significant volumes of offshore and onshore wind, solar and conventional generation while also reinforcing the grid to enable this power to reach demand customers throughout the country. This is underscored by the final Price Review 6 (PR6) Determination from our regulator, the approval for our planned investment to strengthen and build out the electricity grid over the next five years (2026-2030).”
Link to full report: All-Island Resource Adequacy Assessment 2026 – 2035
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