The year 2021 was a difficult one for Ireland’s electricity system. Power shortages dominated the headlines about an industry that has delivered Ireland’s greatest success story to date in the area of clean energy.
Ireland’s electricity system operator, EirGrid, issued a high number of alerts indicating that the margin between electricity demand and electricity supply was tight, and the loss of a generator could mean difficulty in meeting demand.
While we had a clear and necessary policy focus on delivering renewable energy to reduce emissions, we had a blind spot when it came to electricity supply security
Like most major crises, there is not one single explanation for how it happened but rather a series of events that tend to reinforce and amplify each other. In Ireland’s case, specific factors around supply, demand and an ageing fleet of conventional power stations provided a coincidence of crises that brought us to where we are today.
However, this predicament isn’t just about “bad luck”; at its core was a blindness to the need to build conventional power plants that allowed us to sleepwalk into a tight spot. We were blinded in equal measures by long-term optimism on how easy it is to run a power system with a lot of wind, while also being victims of our own past success.
Over the period from 2005 to 2020, Ireland’s big (and only significant) success story in addressing climate change was in the electricity sector.
We nearly halved carbon dioxide emissions from electricity supply, reducing it from more than 15 million tonnes to eight million tonnes.
This was mostly delivered through a combination of increasing the amount of wind power and by retiring older fossil fuel (oil and peat) power plants.
It was an extraordinary achievement because it was hugely challenging to integrate large amounts of variable wind energy on to our power system because of the relatively small size of our grid.
Over this period our usage of electricity increased, which added to the challenge.
Wind energy provided nearly 40 per cent of our electricity in 2020. It was achieved through a combination of policy and engineering as well as societal and community support.
But while we had a clear and necessary policy focus on delivering renewable energy to reduce emissions, we had a blind spot when it came to electricity supply security.
Studies demonstrated that renewables such as wind and solar energy are the best way to reduce emissions in our power sector.
They do this by reducing the use of fossil fuel power stations but renewables do not replace the need for fossil fuel power stations, which are required when weather-driven generation is low across Ireland and northwest Europe.
This came into sharp focus in 2021 as, it was a relatively “low” wind year.
Despite continued growth in wind power in 2021, wind energy provided about 30 per cent of our electricity over the year (compared with nearly 40 per cent the previous year).
At the same time, the economy emerged from the Covid-19 pandemic restrictions, which allowed electricity demand to rebound quickly.
While much focus was given to data centres in the crisis, the actual growth in data centre demand from 2020 to 2021 was modest and played a minor role.
However, the projected growth of data centres from now to 2030 is a valid concern that requires attention.
The last element of the crisis was that power plants we rely on were not available because of delays in maintenance and repairs during 2020 due to the pandemic restrictions.
This magnified existing problems in meeting demand and were central to the triggering of alerts by EirGrid, which remarkably managed to ensure the lights never went out during the year.
But we may not always be so fortunate, and we need to plan better for the future and look to scientific evidence on how we transition away from fossil fuels rather than the simplified ideology of no fossil fuels at all in the power system.
The possible risks relating to electricity supply shortages are flagged each year by EirGrid as well as the projected growth in electricity demand associated with data centres, as is the growth in electricity generation from wind energy.
It's not easy to build large electricity infrastructure, but it is essential that the Government has a clear focus on energy security and decarbonisation as the two go hand in hand
The responses required to address these risks include technical changes to grid operation, sufficient gas-fired electricity generating capacity and electricity storage.
More attention should have been paid to ensuring Ireland grew sufficient gas-fired generating capacity to balance growing wind power and to meet increasing electricity demands.
We need to build more conventional gas capacity, but we must also understand that it will be used less.
This is better for emissions but challenging for the market which is transitioning from a fossil to a renewable world.
Incentives for building renewables are strong but incentives for building conventional capacity are not; they not only carry financial risk but also reputational risk.
Building something that few people want but the power system needs is a defining challenge for Ireland in the next five years.
A further medium-term challenge is to achieve a zero-emissions power system, which will include using zero-emissions fuels in power stations and/or removing the emissions coming out.
It’s not easy to build large electricity infrastructure, but it is essential that the Government has a clear focus on energy security and decarbonisation as the two go hand in hand.
As Ireland sets out its stall for power system climate ambition and looks to a target of providing 80 per cent of electricity from clean renewables in 2030, it must remember that the remaining 20 per cent of electricity that will come from conventional power stations is just as important, not only for integrating wind but also for keeping the lights on.
Dr Paul Deane is senior research fellow in clean energy futures and Brian Ó Gallachóir is professor of energy engineering at University College Cork