EirGrid publishes Winter Outlook showing improved adequacy forecast for winter period and lower potential for System Alerts

EirGrid, which is responsible for operating, developing and enhancing the electricity grid and market, has forecast that there will be adequate generation capacity and a continued reduced risk of system alerts in the coming months, as the Winter Outlook for 2026/27 is published.

The annual Winter Outlook helps to inform the electricity industry and supports preparation for the coming months.

The report covers the period from 2 November 2026 to 4 April 2027. It is a point-in-time assessment based on the best information available.

The data-freeze date for the outlook was 2 September 2026. In the Winter Outlook, EirGrid studies the expected generation capacity and the forecast electricity demand to determine if there is an adequate generation capacity margin. 

This year’s report shows an improved outlook for the winter ahead. The risk of insufficient generation being available to meet demand is now notably lower than it has been in recent years.

It reflects the positive impact of additional generation and battery storage capacity that has come onto the system, along with out of market measures strengthening Ireland’s overall security of electricity supply.

The analysis identifies the Loss of Load Expectation (LOLE) which is a mathematical formula, based on studies, of the number of hours in a period (typically per year) during which the available generation will be inadequate to meet demand. 

This standard is set by the Department of Climate, Energy and the Environment (DCEE). The higher this number is, the greater the risk that there will be insufficient generation available. It is important to note that this metric is a measure of risk but does not necessarily mean that electricity consumers will be without supply for any period.

According to this year’s Winter Outlook, the LOLE in Ireland for the five months of the winter period is 0.8 hours, which is inside the 3-hour annual LOLE Standard set for Ireland. 

The LOLE for this winter is down from 1.1 hours last winter, 3.6 hours the winter before that and 21 hours the winter before.

The generation adequacy situation in Ireland has improved for a number of reasons, including new sources of generation on the system in the form of 275 MW of new gas fired peaker plants and 63 MW of new batteries delivered through the Capacity Market, as well as the addition of an extra 809 MW of wind and solar generation.

For context, it is estimated that 1 GW (1,000 MW) is enough to power about 500,000 customers.

Other factors include interconnection and the continued implementation of the Security of Supply Programme which is led by the Commission for Regulation of Utilities (CRU).

Through the Security of Supply programme 750 MW of Retained Existing Units (REU) at Moneypoint and 649 MW of Temporary Emergency Generation (TEG) is available as additional out-of-market generation to system operators in EirGrid’s control centre, if required.

The system may enter the Alert (Amber) State at times, most likely at periods of low wind and low interconnector imports. 

There is a low probability of the system entering the Emergency (Red) State, due to insufficient generation being available to meet the demand.

The report notes that protocols are in place with large energy users that would mitigate any impact on homes and businesses, where sufficient notice of an event can be provided.

The peak demand for electricity last winter of 5,916MW was recorded on 5 January 2026, below EirGrid’s median forecast peak of 6,044 MW. For Winter Outlook 2026/27, our median forecast peak demand is 6,101 MW.

The analysis of Ireland’s peak demand over winter indicates that a 1°C decrease in outside temperature results in a 55 MW increase in peak demand, meaning electricity demand in the winter is heavily influenced by weather conditions.

Diarmaid Gillespie, Director of System Operations at EirGrid, said: “This year’s assessment shows an improved outlook for the winter period, with the risk of insufficient generation being available to meet demand now notably lower than in recent years and well within the standards set by the Department of Climate, Energy and the Environment.

"The reduction in Loss of Load Expectation (LOLE) reflects the positive impact of additional generation and battery storage capacity coming onto the system, along with out of market measures strengthening Ireland’s overall security of electricity supply.

"Keeping Ireland powered is a key pillar in our strategy. As demand for electricity continues to grow and generation sources are increasingly from renewable sources, we remain focused on both operating the grid of today and preparing for the grid of tomorrow.

"Through investment in infrastructure, markets and system capabilities, we are strengthening Ireland’s energy security while enabling economic growth, supporting regional development and accelerating the transition to a cleaner energy future.”