Summary
- Research launched by MEP Lynn Boylan examines how Irish grid reinforcement costs are allocated.
- Its conclusion that households bear part of data-centre-driven reinforcement is an attributed research finding, not a regulatory determination.
- Ireland's current connection regime already subjects large data centre applications to network-capacity and system constraints.
A new Irish report has put the allocation of electricity-network costs associated with data centre growth under scrutiny, arguing that connection charges paid by individual projects do not necessarily capture the wider reinforcement expenditure created by large new loads.
The research, written by Trinity College Dublin researcher Eve Ryan and launched by Sinn Féin MEP Lynn Boylan, examines how regulatory decisions divide network expansion costs between individual data centre customers and electricity users more broadly.
Boylan argues that households are indirectly paying part of the cost of network reinforcement associated with new data centre demand. That conclusion is the position advanced by the report and should not be read as a finding by the Commission for Regulation of Utilities, EirGrid, or another statutory authority.
The distinction between a connection charge and wider network expenditure is central to the debate. A large customer can pay project-specific costs associated with connecting to the electricity system while reinforcement elsewhere in the transmission or distribution network is recovered through regulated network tariffs spread across customer categories.
Ireland already operates a constrained connection regime
Ireland’s data centre connection policy has become substantially tighter as large loads have absorbed capacity around Dublin and other constrained areas.
The Commission for Regulation of Utilities published an updated electricity connection policy in December 2025. It requires new data centres to provide generation or storage corresponding to their requested demand, with the resource capable of participating in the electricity market. Renewable-energy and emissions reporting requirements also form part of the policy.
EirGrid’s current connection process assesses the maximum import capacity requested by a data centre, with that contracted capacity feeding into network-capacity charging. Applications can be reassessed if requested capacity changes, and constrained locations remain a major determinant of whether projects can proceed.
Those rules deal with whether and how a facility can connect. Ryan’s research raises a different question: once the system requires new substations, transmission reinforcements, or other shared assets, how much of the cost should be directly attributed to the large load that contributed to the requirement?
That is not straightforward because major grid investments rarely serve only one customer for their entire life. A new substation or transmission circuit may initially be driven by one cluster of large connections but subsequently support housing, industry, renewable generation, electrification, and other demand.
Regulators therefore have to distinguish between dedicated assets that can reasonably be charged directly to a customer and shared network development that forms part of a broader regulated system.
The cost question is becoming as important as access
Large data centres complicate network investment because one connection can reserve a substantial block of capacity. ESB Networks has previously told the CRU that individual large-energy-user applications can absorb available headroom and make an area constrained, while major reinforcement projects can require long development lead times.
The policy argument advanced by Boylan is that more of the incremental expenditure associated with such demand should be recovered from the projects creating it. The countervailing regulatory consideration is that network assets often provide system-wide value, making a simple one-project-one-cost allocation difficult.
There is also a question of project maturity. Charging large users for infrastructure built around speculative demand creates one set of risks; allowing the wider customer base to fund assets for projects that never proceed creates another. Connection policy, financial security, and network charging therefore increasingly have to be considered together.
Ryan’s report adds another pressure point to a market already debating how much data centre capacity Ireland can accommodate, how quickly low-carbon generation can expand, and what supporting infrastructure new loads should provide themselves.
The next regulatory question is unlikely to be whether large users contribute at all — they already pay connection and network charges — but whether the charging structure accurately reflects the timing, location, and reinforcement consequences of very large individual loads.
