DATA CENTRES USING backup and emergency generators in Ireland are releasing huge quantities of carbon dioxide emissions, a new investigation has revealed.

The Journal Investigates has uncovered that over 135,000 tonnes of CO2 was emitted from these centres in the last five years from generators not on the electricity grid.

This amount of CO2 is comparable to running roughly 33,750 cars for a year in terms of the climate pollution produced.

These backup generators are used to keep the energy-hungry equipment in these centres operational during times of grid connectivity issues.

The investigation also highlights how some planned data centres intend to be powered by natural gas because they cannot be connected to the grid as it is under such strain.

Our team has also trawled through planning applications from every local authority to map data centres. Although these locations aren’t top-secret, they are not widely advertised by their operators and are often located in industrial estates.

We have found as many as 89 data centres believed to be operational, the vast majority of which are located in the Greater Dublin area, with at least 13 data centres in the capital each using as much power as Kilkenny City.

The rapid expansion of data centres located in Ireland has accelerated in recent years despite challenges for providers in securing connections to the national electricity grid.

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In early 2022, EirGrid imposed a de facto moratorium on connecting new data centres to the grid due to concerns about capacity. We reveal how some new data centres are proposing to use natural gas, a fossil fuel, to circumvent the grid connection challenges.

The expansion of the sector is expected to hit new heights in the coming years as the shift towards artificial intelligence puts greater demands on the need for large data centres.

Large data centres use same energy as large town

Under EU rules, large data centres in Ireland are required to record and report the amount of CO2 they produce from emergency and backup generators.

The EU Emissions Trading System covers a range of different industries but any data centre with a “total rated thermal input exceeding 20 MW” is required to hold a Greenhouse Gas Emissions (GHG) permit and report their emissions each year.

Dr Paul Deane, a senior lecturer in clean energy at University College Cork (UCC), says data centres of this size are quite large and would use the same amount of electricity as a large town.

A total of 24 GHG permits have been issued by the Environmental Protection Agency (EPA) to data centre operators in Ireland, with more than 800 emergency and backup generators of varying sizes listed as emission sources.

A common fuel used in these generators is gas oil, also known as red diesel, though some operators are switching to biofuels such as Hydrotreated Vegetable Oil.

Our investigative unit reviewed the Annual Verified Emissions of Irish data centres and found that 181,553 tonnes of CO2 have been emitted from data centres dating back to 2005.

Almost 94% (135,000 tonnes of CO2) of these emissions were since 2017 as the majority of data centres were brought online in recent years.

Deane says that while these emissions pale in comparison to Ireland’s annual CO2 emissions – Ireland as a whole emitted more than 55 million tonnes of carbon dioxide equivalent last year according to the EPA – “when you’re trying to reduce emissions as much as possible, every tonne of carbon dioxide counts”.

One data centre campus owned by EdgeConneX in Lucan, Co Dublin has emitted by far the highest from backup and emergency generators of any other campus, with almost 130,000 tonnes of CO2 since coming online in 2017.

The 28 emergency generators listed at the site are responsible for these emissions, keeping three data centres online.

We have contacted EdgeConneX for comment.

The Journal Investigates found planning files granting permission for two additional large data centres at the same EdgeConneX campus in Dublin.

From outside the campus, it appears that these have been built or are nearing completion, but it is unclear whether they are operational. Planning permission for a further data centre on the site was rejected in 2023, but the decision by South Dublin County Council has been appealed to An Bórd Pleanála.

Data centres operated by the four main big tech companies – Amazon, Microsoft, Google and Meta – have also contributed almost 30,000 tonnes of carbon dioxide from their backup generators since becoming operational, though the majority of this (18,000 tonnes) came from Amazon’s data centres.

The Journal Investigates contacted all four companies for comment.

A spokesperson for Microsoft cited “new challenges” posed by the power demands of artificial intelligence in meeting sustainability goals, but added, “we remain resolute in our commitment to meet our climate goals”.

No response was received from Google, while spokespeople for Amazon and Meta both pointed to how their respective companies match electricity use with 100% renewable energy.

This means that for all the emissions generated by the company, it purchases renewable energy from wind or solar farms across the country, balancing its emissions.

Deane, however, says that this matching of renewable energy, while representing progress, is somewhat opaque.

“That’s a good step in the right direction, but it’s really not good enough. It doesn’t mean that you’re powered by renewables every hour,” he says. “It just essentially means that you’re using a synthetic accounting exercise to offset your emission over the course of a year.”

Deane says that for data centre operators to be serious about climate change, they should be using clean energy all of the time and not just “balancing their energy load over the course of the year”.

Projected to use half of Ireland’s metered electricity

Large data centres must also apply for a license from the EPA if they want to run their backup generators for more than 18 hours a year.

These Industrial Emissions licences are granted for specified industrial and agricultural activities and are required for data centres with a thermal input equal to or greater than 50MW.

Deane says that a data centre or campus of this size would use the equivalent amount of electricity as a small city such as Kilkenny. The EPA has approved 15 Industrial Emissions licences for data centres.

As part of the application for an Industrial Emissions licence, operators must submit their planned electricity use per year.

The Journal Investigates can reveal the total electricity demand of the licenced data centres surpasses 10,000 gigawatt-hours annually.

A number of data centres have also applied for an Industrial Emissions licence and are awaiting a decision from the EPA. If all these licences were granted, the total electricity demand would surpass 16,000 gigawatt-hours every year.

This would be equivalent to over half the total metered electricity consumption in Ireland last year.

However, it should be noted that these figures differ substantially from figures provided by the Central Statistics Office (CSO).

In 2023, the CSO estimated that the total metered electricity consumption of data centres was just over 6,300 gigawatt-hours. Similarly, EirGrid’s projected electricity demand of data centres in 2030 comes to 13,000 gigawatt-hours, also below the operator-provided projections in the Industrial Emissions licences.

A spokesperson for the EPA told The Journal Investigates the applicant signs a declaration that all information provided is “truthful, accurate and complete to the best of their knowledge and belief”.

The spokesperson, accounting for the discrepancy, also said that data centre operators may use other sources other than mains electricity to power their operations.

On the inflated figures, Deane says it is difficult to say whether companies are overestimating to give themselves room to grow or if there is some element of calculated speculation in the numbers.

Either way, he says, “they point to an enormous appetite for the industry to grow its consumption well beyond what the system can currently cope with and certainly well beyond our legal limits for climate emission reductions.”

A major factor in the continued growth of data centres is the rising demand for artificial intelligence.

Speaking at an AI conference in Galway in September Minister of State at the Department of Enterprise Dara Calleary said that the government wants 75% of Irish companies to be using AI by 2030.

In order to reach this target, more data centres will likely be required to meet the massive power demands of artificial intelligence.

Shift to data centres powered by natural gas

Gas Networks Ireland has received 22 formal enquiries from data centres about connecting to the gas network, according to data released by the Minister for Environment Eamon Ryan in early November in answer to a parliamentary question by Sinn Féin’s Eoin Ó Broin.

The Industrial Emissions licence applications also show that some data centres are relying on natural gas to circumvent the challenges with grid connections.

Some of these plans include building on-site power generation facilities run on natural gas that only operate during times of constrained electricity demand from the grid.

A number of these peaking plants, as they are known, can also send electricity generated from natural gas back to the grid and operate as an alternative power source for the data centres.

Hannah Daly, a Professor in sustainable energy at UCC, says once the infrastructure of these plants is built, there’s an incentive to continue using it, almost putting a lock on fossil fuels and leaving less incentive to transition to a fully renewable energy supply.

The Industrial Emissions licences also show some data centres will rely on natural gas until such a time when a connection to the electricity grid can be supplied.

A data centre campus in Grange Castle, Dublin operated by US developer Vantage is one of those sites planning to use natural gas.

Documents submitted to EPA by the company and reviewed by The Journal Investigates say that “EirGrid has confirmed that there is not sufficient capacity in the current network to support this development”.

In lieu of this, the data centre will be powered by natural gas “until such time that a connection to the EirGrid is established”.

A spokesperson for Vantage told The Journal Investigates that the power generation plant “is designed to complement the grid connection, not replace it” and that grid power will be used to power the data centre once construction is completed.

They also said that the company “has a connection agreement with EirGrid” but that the data centre will be supported by the power generation plant “given the temporary power constraints in Dublin”.

Another data centre, this time opened by UK-headquartered Pure DC, will also be powered by electricity generated from natural gas due to challenges in securing a grid connection.

A spokesperson for Pure DC confirmed that the data centre campus is currently powered “using natural gas and backup generators fuelled with Hydrotreated Vegetable Oil”, adding that it is planning to transition to a sustainable power solution “as soon as viable”.

Daly says the shift towards using natural gas is “far more carbon intensive than electricity from the grid because it’s less efficient and entirely based on fossil fuels”.

The biggest problem, however, she says is that natural gas used by data centres is not quantified in Ireland’s greenhouse gas emission projections “which means it’s a massive blind spot for our carbon our climate action plan”.

“We’re operating completely in the dark here and there’s a significant risk that this will lock in more inefficient fossil fuel use, which would be a major threat to carbon budgets,” she adds.

Mapping Ireland’s data centres

The number of data centres in Ireland is a somewhat ambiguous figure. According to energy consultants BitPower, there are 92 data centres in Ireland, but it offers little information about where they are.

The Journal Investigates asked the Commission for Regulation of Utilities for details of the data centre grid connections in Ireland, but it refused to provide this information saying it was “commercially sensitive”.

Our investigative unit trawled through planning records from every local authority and used online web sources to compile a comprehensive list of the data centres believed to be currently active in Ireland.

Through this, we found a total of 89 data centres, roughly in line with the figure provided by BitPower. We also found 11 more data centres that are at various stages of development and may already be operational in some capacity. And over 30 more have been granted planning permission or are under appeal to An Bórd Pleanála.

If all these data centres were built, there would be close to 130 data centres in Ireland.

The above map shows that the vast majority of data centres are located around the Greater Dublin area, with large clusters built around Clonshaugh, Blanchardstown and Clondalkin.

These data centres can vary greatly in size, with little information on their capacity available, though Bitpower’s report says there are 64 data centres in Ireland that use between 10MW (mega-watts) and 50MW.

As previously mentioned, data centres of this size use the same amount of electricity as a small city, such as Kilkenny.

The Journal Investigates was able to locate a number of these large data centre campuses by reviewing Industrial Emissions licence applications and cross-referencing with planning records.

Of the 15 licences that have been issued by the EPA, 13 of them relate to data centres based in Dublin, meaning the electricity demand of the capital is enormous.

Seven of the nine outstanding applications are also located in Dublin, though one is an updated application of an existing licence.

Daly says that Dublin has emerged as one of the five major data centre hubs in Europe and is putting pressure on the physical infrastructure of the electricity grid.

She says the grid has reached a saturation point in terms of supply which is pushing data centres to invest in natural gas to power the growing demands of data centres.

As more data centres opt for natural gas, the pressure on the electricity grid may reduce, but it will cause “greater greenhouse gas emissions”, threatening Ireland’s climate commitments.

Reporter: Conor O’Carroll • Editor: Maria Delaney • Main Image Design: Lorcan O’Reilly • Social Media: Sadbh Cox

This investigation was developed with the support of Journalismfund Europe as part of a project with Pablo Jiménez Arandia in Spain.