Baseload is the minimum level of electricity demand on a power grid at any given time – the amount of power a country needs even at 4am on a mild night when most people are asleep and factories are idle. Think of it as the floor that demand never drops below. Traditionally, utilities designed large power plants – coal, nuclear or gas-fired stations that run continuously – to serve this constant background demand. These “baseload plants” operated around the clock because they were expensive to start and stop but cheap to run once firing.
In Ireland, where the electricity system is relatively small and isolated, the baseload concept has always had particular significance. The country’s total system demand in 2024 was 33,791 GWh, with a record peak of 6,024 MW hit in January 2025 – the first time demand passed the 6,000 MW mark. But during low-demand periods on mild summer nights, all-island system demand can drop to around 3,100 MW – barely half the winter peak. How that minimum demand is served – and whether it still needs to come from fossil fuel plants – is one of the central questions in Ireland’s energy transition.
🌿 How Baseload Relates to Ireland’s Grid
Ireland’s power system has historically relied on natural gas as its primary fuel, with gas-fired plants providing both baseload and peak generation. Unlike countries with nuclear fleets or large hydroelectric dams, Ireland has no conventional large-scale baseload generators that run 24/7 at fixed output. Instead, gas plants ramp up and down to follow demand, while wind energy – which provided 33% of Ireland’s electricity in 2024 – feeds in whatever the weather allows.
This creates a challenge. Wind farms generated 13,258 GWh across the island in 2024, more than one and a half times the total consumption of all residential customers. On windy nights, renewable generation can easily exceed the baseload demand level, meaning the grid has more clean electricity available than it can use. But the grid still requires a minimum number of large conventional generators to stay online for system stability – currently eight units across the island (five in Ireland, three in Northern Ireland). This minimum generation requirement, rather than lack of wind, is now the primary reason renewable energy gets curtailed in Ireland.
🌿 Why the Baseload Concept Is Changing
The traditional view of baseload as something only large fossil fuel or nuclear plants can provide is being overtaken by technology. Battery storage, interconnectors and demand-side flexibility are all capable of serving the constant background demand that baseload plants once monopolised.
Ireland’s Celtic Interconnector to France, currently under construction and due to be operational by 2027, will add 700 MW of import/export capacity, allowing surplus renewable generation to flow to European markets and imported electricity to fill gaps. EirGrid is also working to reduce the minimum number of conventional units required online from eight to seven, with further reductions planned as grid-forming battery technology matures. The 756 MW of battery storage already operational across 21 systems on the island is beginning to provide the fast-response services that historically only spinning fossil fuel generators could offer.
By 2034, EirGrid projects peak demand will exceed 7,000 MW, driven by data centres, heat pumps and electric vehicles. The proportion of demand from heat pumps alone is expected to rise from 3% in 2025 to 10% by 2034. Meeting this growing demand – including baseload – without simply building more gas plants will require a fundamental shift in how the grid operates, moving from a system designed around always-on fossil fuel generators to one built on variable renewables backed by storage, interconnection and flexible demand.
🌿 Baseload vs Load-Following vs Peaking
Electricity generation is traditionally divided into three tiers. Baseload serves the constant minimum demand. Load-following generation ramps up and down to track the daily demand curve as people wake up, go to work and cook dinner. Peaking plants fire up only during the highest demand periods – cold winter evenings in Ireland when electric heating, lighting and cooking coincide. In Ireland’s single electricity market, gas plants perform all three roles depending on conditions, while wind contributes across the board whenever the resource is available. Understanding this hierarchy helps explain why some generators run most of the time while others sit idle for months, waiting for those brief hours of extreme demand.
🌿 Frequently Asked Questions
🌿 Does Ireland have any nuclear baseload power?
No. Ireland has no nuclear power stations and no current plans to build any. The country’s baseload and general electricity needs are met primarily by natural gas generation, supplemented by wind, solar, biomass, hydro and imported electricity via interconnectors to Great Britain and, from 2027, France.
🌿 Can wind energy serve as baseload?
Wind energy is variable – it generates electricity when the wind blows, not on a fixed schedule. However, at the system level, combining wind with battery storage, interconnectors and flexible demand can deliver the same continuous supply that baseload plants provide. Ireland’s SNSP limit of 75% already allows the grid to run predominantly on non-synchronous renewable generation for extended periods, and EirGrid is working toward raising this further.
🌿 What is the minimum number of conventional units?
EirGrid currently requires a minimum of eight large conventional (synchronous) generators to be online across the island at all times – five in Ireland and three in Northern Ireland. This requirement exists to maintain system stability, frequency control and reserve capacity. Trials are underway to reduce this to seven units, which would allow more space for renewable generation during low-demand periods and reduce curtailment of wind and solar.
🌿 What happens to baseload demand as Ireland electrifies?
As more homes install heat pumps and more drivers switch to electric vehicles, the overall demand curve changes. Overnight charging of EVs and the continuous low-level draw of heat pumps may actually raise the baseload floor, increasing the minimum demand that must be served around the clock. EirGrid forecasts that data centres and large energy users will consume around 31% of total electricity demand by 2034, much of it running 24/7 as classic baseload demand.