Originally published on the Irish Examiner website in May 2026 as part of the Renewable Island supplement.
By Thomas O’ Sullivan, Co-Founder of FlexPower Solutions.
As I stood in the turbine hall at Ardnacrusha recently I tried to imagine Ireland in 1923. A newly independent State committing 20 per cent of its budget to the Shannon hydroelectric project; a project that, when completed, produced far more electricity than the country could use.
For years after the turbines started turning, the ESB campaigned to persuade Irish people to embrace this strange new resource. Famously, the first house in any village to be electrified was the priest’s house, if the community’s spiritual leader adopted it, the rest would follow.
The Monument of Our Generation
Ardnacrusha was 85 megawatts in size. Today, Ireland has committed to 22,000 megawatts of wind and solar, quadrupling our current renewable generation capacity. That is not a plan for today’s demand; it is a monument to a future electrified economy, just as Ardnacrusha was in the 1920’s. And, like Ardnacrusha in its early years, when it was diverting water down its slipways away from the turbines because we did not have use for the electricity, today we are again generating more renewable energy than we can consume.
In August 2024, 27 per cent of available wind generation was switched off. In Northern Ireland that figure reached 43 per cent. When we reach our wind and solar targets, I estimate up to 17 terawatt hours of renewable electricity could go unused every year, a staggering volume.
That unused electricity goes by many names: curtailment, constraints, over-generation, dispatch down, wastage but I want to reframe that. This energy is not wasted; it is an opportunity. The question is how will this opportunity be used by Ireland. I believe the answer is already connected to our grid.
The Hidden Giant
Irish industry consumes 20.7 terawatt hours [i]of heat every year, mainly imported fossil fuels. Breweries, dairies, pharmaceutical plants, food manufacturers; the boiler house is the heart of every one of them. I spent the early part of my career as a mechanical engineer criss-crossing Ireland installing heating systems. The manufacturing varied but the need never did. They all needed heat. They all needed steam. They still do.
The projected unused renewables is closely matched to the entire annual industrial heat demand of the country. That in my opinion is an opportunity.
Over €1.2 billion leaves Ireland every year to pay for the imported natural gas that heats our factories according to SEAI’s Commercial Fuel Cost Comparison. Every time a wind turbine is turned off, a house or a factory burns gas instead. The electricity and heat sectors have simply never been in the same room.
Distributed is Good
Ireland’s large industrial heat users are not clustered in a single location, they are distributed across the island. Often, they occupy the very same grid corridors where wind energy constraint is highest. When we turn on an electrode boiler at an industrial site we’re using wind power that might otherwise be wasted.
This ‘Green Soak’ is not a concept. Having installed an electrode boiler at an industrial site in Co. Limerick, I traded its 25 megawatts of energy over the past two years. Thanks to efficient wholesale market prices, it delivers steam at a lower cost than burning gas. Having no volume-limit, it runs for days undisturbed when wind is highest – making savings by comparison to the electricity price in every hour during which it runs.
This is just one site but other pioneering industrial heat users are joining this fleet of flexible consumers, helping meet our 2030 targets and pave the way for domestic heat applications. Ireland must aspire to affordable zero-carbon heat in commercial and domestic settings through flexible electrification.
What Needs to Change
The technology works. The geography is right. Three policy changes would unlock this opportunity at scale.
First, we need to reform non-energy charges. The wholesale market generates efficient cost signals, but the Regulatory structure of applying charges locks in fossil fuel usage. They make electricity prohibitively expensive even when the market price approaches zero. Efficient usage reduces electricity costs for all households in the country.
Second, we have to make better use of the existing grid. Government has issued a clear mandate to enable flexible consumers. Non-firm import capacity – meaning the grid operator can increase power consumption in times of excess – is needed to allow flexible consumers utilise the grid they are already connected to and to consume the renewable electricity capacity already built.
Finally, when the wind is blowing and prices are low; flexible electricity users need a clear signal to switch on.
Ardnacrusha was the monument of the 1920’s. Wind and solar are the monuments of our generation. Just as the ESB once had to persuade Ireland to use its indigenous electricity, we now need to connect the available wind with the heat that homes and industry need every day.
The turbines are already turning. The boiler houses are already there. The grid connecting them already exists. We just need to get switched on.
Thomas O’Sullivan is co-founder of Flexible Power Solutions Ltd. He previously spent 18 years with Irelands largest heat user as Energy Trader and Energy Lead.