This year has been a year of substantial change both in how the market operates in terms of trading but also physical infrastructure changes such as the addition of new Data Centres, the Greenlink Interconnector, trading system changes, energy storage, etc. Let’s have a look at how these changes have left us prepared for the coming Winter months.

This rock on the edge of the Atlantic may seem a little isolated but we are in fact very connected to our nearest neighbour GB by three interconnectors (Moyle, EWIC & Greenlink) contributing their electricity generation to our fuel mix and allowing us export options for those times when we have lots of wind here. Interconnection is massively important for any market but maybe more important for the island of Ireland than other markets.

There are also a number of new interconnectors on the way in the future, the closest of which is the Celtic Interconnector, construction of which is already well underway. In August they began laying the underwater cable marking another milestone for the project. When it’s finished it will run 575 km from Cork to Brittany in France and allow for the exchange of 700 MW of electricity. Much of the onshore work where the cable lands in Ireland and the converter station in Carrigtwohill has been completed already so the project is making good progress. Originally it was due to be completed and operational in 2026 but now Spring 2028 is the expected operational date.

The Government of Ireland dropped the news last month that a new interconnector was discussed between Minister Darragh O’Brien and his Spanish counterpart this week. A Memorandum of Understanding will likely be signed in the Spring. Spain regularly has excess power at certain times of year. This would allow it to export to Ireland and vice versa. It also acts to enhance our security of supply by being connected to three countries with different energy profiles. The project may be co-funded between Ireland, Spain and Europe but it’s quite a few years away for now. Much closer on the horizon is Winter which feels like it’s already landed here on the island of Ireland with all this stormy weather we’re having!

EirGrid (the transmission operator for the Republic of Ireland) just published their Winter Outlook and it’s worth a read. This is a document where the TSO looks ahead to the coming Winter season, breaks down the available generation and forecasts how resilient the system will likely be over that period.

So, imagine you’re EirGrid. Your goal in the Wintertime is to identify those periods where the gap between generation capacity and peak demand is low and the system may be at greater risk as a result. What do they take into consideration when they’re preparing these outlooks? They face multiple challenges when trying to keep things secure. From weather impacts like cold snaps and storms to outages or changes in customer behaviour or geo-political issues.

When compiling this outlook, EirGrid look at the Loss of Load Expectation (LOLE) which is a mathematical formula of the number of hours in a year during which the available generation will be inadequate to meet demand. The higher this number is, the greater the risk. So, it’s welcome news then that the LOLE for 2025 is just 1.1 hours. The standard required is 3 hours per year so its within target.

How does this year compare to previous years? The LOLE in 2024 was 3.6 hours, just above the 3 hour standard. Whereas this year, there’s a lot more emergency generation available that has been procured by EirGrid in preparation for the Winter. Combined with the medium case interconnector assumption being boosted by the presence of Greenlink it means that there’s more headroom this year compared to last year despite the increasing demand expected.

Thanks to new batteries along with the interconnectors, temporary emergency generation (TEG) power plants in Dublin, the midlands and Shannon the risk of blackout is the lowest it’s been in six years.

Author: Joseph Cullen