Kilshane Energy v EirGrid (No. 2): Exceptional Solicitor–Client Costs in Judicial Review Require Proven Serious Non‑Disclosure and Demonstrable Prejudice

Kilshane Energy v EirGrid (No. 2): Exceptional Solicitor–Client Costs in Judicial Review Require Proven Serious Non‑Disclosure and Demonstrable Prejudice

1. Introduction

This ex tempore judgment of O’Higgins J in Kilshane Energy Limited v Eirgrid plc & anor (No. 2) [2025] IEHC 710 concerns a discrete but significant issue: when, if ever, a public body’s alleged breach of its duty of candour in judicial review proceedings justifies an order for costs on the solicitor–client (“legal practitioner and client”) basis, rather than the usual party–party basis.

The applicant, Kilshane Energy Limited (“Kilshane”), had succeeded in substantive judicial review proceedings against a refusal to qualify its generating units for participation in an electricity capacity auction (see the earlier judgment, Kilshane & Others v EirGrid plc and the CRU [2025] IEHC 174). Following that success, the Commission for Regulation of Utilities (“CRU”) reconsidered the matter on remittal and received a detailed technical memorandum (the “EirGrid report”) from the first respondent, EirGrid plc (“EirGrid”), the transmission system operator.

Kilshane contended that parts of this later EirGrid report revealed “new reasons” for its original refusal to qualify Kilshane’s units—reasons that, it said, ought to have been put before the High Court from the outset under the public law duty of candour. On this basis, Kilshane sought an exceptional order that its costs be taxed on a solicitor–client basis as a mark of the court’s disapproval of EirGrid’s alleged non-disclosure.

EirGrid accepted that Kilshane was entitled to its costs of the substantive judicial review on the usual party–party basis, but denied any breach of the duty of candour and opposed the elevated costs order. The judgment therefore grapples with:

  • the nature and scope of the duty of candour in judicial review for public bodies;
  • the threshold for departing from the default party–party costs order in favour of solicitor–client costs; and
  • how alleged non-disclosure must be proved and what consequences must be shown.

The decision also addresses the “costs of the costs application” itself, and whether the usual “costs follow the event” rule should apply where an application for enhanced costs fails but is not wholly baseless.

2. Summary of the Judgment

2.1 Outcome on the enhanced costs application

The High Court:

  • Refused to order costs on a solicitor–client (legal practitioner and client) basis in favour of Kilshane.
  • Confirmed that the default costs position—party–party costs—remains applicable to the substantive judicial review, which Kilshane had won.
  • Held that although the later EirGrid report contained some new reasons and an adjusted focus compared with earlier materials, Kilshane had not proved to the requisite standard a wrongful or blatant withholding of information amounting to a breach of the duty of candour sufficient to justify exceptional costs.
  • Emphasised that the exceptional jurisdiction to award solicitor–client costs requires:
    • clear and specific proof of serious or blatant misconduct (such as non-disclosure), and
    • demonstrable, concrete consequences (prejudice) arising from that misconduct.

2.2 Outcome on the costs of the costs application

In relation to who should bear the costs of the unsuccessful solicitor–client costs motion, the Court:

  • Recognised that EirGrid, as the successful party on the motion, would ordinarily be entitled to its costs, following the “costs follow the event” principle.
  • Nonetheless exercised its discretion to depart from the usual rule, on the basis that:
    • there was a certain degree of justification for Kilshane’s concerns about new information and adjusted focus in the EirGrid report; and
    • the application, though unsuccessful, was not wholly baseless.
  • Made no order as to costs on the motion: each side must bear its own costs of the enhanced costs application.

The judgment therefore:

  • reaffirms the high threshold for awarding solicitor–client costs based on alleged breach of the duty of candour; and
  • illustrates the Court’s willingness, in appropriate cases, to temper the “costs follow the event” rule for costs-of-costs applications where those applications raised genuine issues, even if ultimately unsuccessful.

3. Factual and Procedural Background

3.1 The capacity auction and the underlying judicial review

Kilshane sought to have certain “candidate units” (generation assets) qualified for participation in a T‑4 electricity capacity auction. Qualification is a precondition for competing for capacity payments.

  • EirGrid, as the Transmission System Operator (TSO), is centrally involved in assessing technical feasibility of proposed grid connections.
  • The CRU, as the regulator, ultimately decided not to qualify Kilshane’s units, principally on feasibility grounds relating to the proposed 400kV cable connection from Kilshane’s Huntstown site to Woodland Substation.

Kilshane (with other applicants at that stage) brought judicial review, challenging the refusal. On 10 December 2024, O’Higgins J delivered an oral ruling in their favour and indicated he would quash the CRU’s decision and remit the matter for fresh consideration within a tight timeframe.

3.2 The remittal process and the EirGrid report

In the short interval following the oral ruling:

  • Kilshane provided additional technical material to the CRU and EirGrid, including a route map and engineering report (H&MV Engineering, 12 December 2024).
  • EirGrid responded with a detailed technical memorandum (the “EirGrid report”, dated 13 December 2024), addressing feasibility in light of this new information.
  • The CRU issued a fresh decision on 16 December 2024 (supplied to the Court).

A key focus in this judgment is paragraph 3.1.3 of the EirGrid report, headed Potential Planning Conditions, which:

  • referred to potential planning conditions on major 400kV grid reinforcement projects (Kildare–Meath, East Meath–North Dublin),
  • highlighted the absence of any existing provision for Kilshane’s connection at Woodland Substation,
  • explained that accommodating Kilshane would require:
    • land acquisition and expansion of Woodland Substation,
    • a new 400kV bay, and
    • possible impacts on other priority EirGrid/DECC projects, including the North–South Interconnector.

Kilshane asserted that these reasons—particularly the need to expand Woodland Substation, associated planning issues, and knock-on effects for EirGrid’s strategic projects—had never been disclosed previously, either in the administrative process or in the substantive judicial review. Those matters, it said, revealed EirGrid’s actual reasons and purported “ulterior motives” for refusing qualification.

3.3 The present application

In this post‑judgment motion, Kilshane sought:

  • an order that its costs of the substantive judicial review be taxed on a legal practitioner and client (solicitor–client) basis;
  • principally on the footing that EirGrid had breached its duty of candour by failing to disclose its “true reasons” for opposing qualification until after the Court’s oral ruling.

The evidential basis for this allegation was set out in:

  • an affidavit of Mr Ciarán Draffin (director of Kilshane), 14 April 2025; and
  • a replying affidavit of Mr Conor Farrell for EirGrid, 16 April/16 May 2025 (the judgment mentions 16 May).

The Court also had before it the affidavits from the substantive proceedings (Draffin, McMullan, Gallery, Farrell) and detailed written and oral submissions from both sides.

4. Issues Before the Court

The judgment frames, explicitly or implicitly, three central issues:

4.1 Has EirGrid breached its duty of candour by failing to disclose its “actual reasons” earlier?

Kilshane argued that EirGrid:

  • failed to put all the cards face upwards on the table (to use the Huddleston formula) in the substantive proceedings;
  • only revealed, in the remittal EirGrid report, that connection of Kilshane’s project conflicted with EirGrid’s own priority grid reinforcement projects and required significant substation expansion; and
  • thereby breached the enhanced duty of candour owed by public bodies in judicial review.

4.2 If there was such a breach, is a solicitor–client costs order justified?

Even assuming some shortfall in candour, the Court had to decide whether:

  • the conduct was of a “particularly serious or blatant” character; and
  • it caused serious consequences or prejudice to Kilshane,

such that the exceptional costs jurisdiction under Order 99, rule 10 and the Trafalgar Developments v Mazepin principles should be invoked.

4.3 Who should bear the costs of this unsuccessful motion?

Given that the motion for enhanced costs failed, the Court had to determine:

  • whether EirGrid should receive its costs of defending the motion, following the usual costs follow the event rule; or
  • whether there was a justification for departing from that rule (and if so, to what extent).

5. Summary of the Court’s Findings

  • The default costs basis in civil litigation remains party–party. Solicitor–client costs are exceptional and require a specific, serious justification.
  • Public bodies in judicial review owe an enhanced duty of candour and cooperation—as per R v Lancashire CC ex p Huddleston and its Irish adoption—but a mere change of emphasis or some additional detail in later documentation does not automatically constitute a breach.
  • The EirGrid report did contain some new reasons and an adjusted focus, particularly in relation to:
    • substation expansion and planning issues, and
    • interactions with other major grid projects.
    However, this did not amount to clear proof of a wrongful or blatant withholding of information.
  • Crucially, Kilshane failed to demonstrate the “consequences” limb of the Trafalgar test—i.e. serious prejudice, in terms of delay, extra cost, or other concrete harm, flowing from the alleged non-disclosure.
  • In these circumstances, the high threshold for solicitor–client costs was not met, and the application was refused.
  • On the costs of the motion, the Court accepted that the application was not frivolous:
    • there was some real substance to Kilshane’s concern about new and adjusted reasons appearing in the EirGrid report; and
    • EirGrid’s own affidavit accepted that the report identified further obstacles to feasibility.
    Therefore, while EirGrid “carried the day”, justice was best served by no order as to costs on the motion.

6. Legal Analysis

6.1 Precedents and Legal Framework

6.1.1 Default rule on costs – McCool Controls v Honeywell [2019] IEHC 695

The parties accepted, and O’Higgins J endorsed, the principle that:

  • where a party is awarded costs, those costs will normally be measured on a party–party basis; and
  • this reflects the general policy that a successful party is indemnified for the costs reasonably and proportionately incurred, but not for every possible item that might appear on its solicitor’s bill.

McCool Controls and Engineering Ltd v Honeywell Control Systems Ltd [2019] IEHC 695 (Simons J) is cited as authority for this default position.

6.1.2 Exceptional costs orders – Trafalgar Developments Ltd v Mazepin [2020] IEHC 13

The core guidance on when to depart from the normal party–party basis comes from Barniville J’s (as he then was) distillation of principles at para 54 of Trafalgar Developments Ltd v Mazepin, summarised and applied by O’Higgins J. These principles, later approved by the Supreme Court in An Bord Bainistíochta, Gaelscoil Moshíológ v Department of Education [2024] IESC 38 (O’Donnell C.J.), can be grouped as follows:

  1. Normal position: Where costs are awarded against one party, they are to be taxed on a party–party basis.
  2. Discretion to depart: The court may direct that costs be taxed on a solicitor–client basis in particular circumstances, if it thinks fit.
  3. Need for a good reason: There must be a good reason to justify the departure from the norm.
  4. Marking disapproval: Such an order is often used to express judicial displeasure or disapproval of the losing party’s conduct.
  5. Types of misconduct that can justify solicitor–client costs include:
    • (a) a particularly serious breach of discovery obligations;
    • (b) abuse of process (e.g. proceedings for an improper purpose or collateral motive);
    • (c) reckless claims of fraud, dishonesty or conspiracy without a prima facie evidential basis; and
    • (d) any other conduct in the commencement or conduct of proceedings—such as particularly serious or blatant breaches of court orders or rules—that merits judicial censure.
  6. Analytical steps for the court: when considering such an order, the court should:
    • (a) clearly identify the impugned conduct;
    • (b) carefully consider the explanation offered;
    • (c) examine the consequences (if any) of that conduct for the other party, in terms of delay, costs or prejudice; and
    • (d) decide whether, in all the circumstances, it is appropriate and in the interests of justice to award solicitor–client costs.
  7. High threshold: a mere breach or failure to comply with rules or orders ordinarily warrants costs on a party–party basis only. An order for solicitor–client costs generally requires:
    • a breach that is particularly serious or blatant; and
    • serious consequences for the other party.

O’Higgins J emphasises that this last point is of particular importance. It signals a deliberately high threshold for exceptional costs orders.

6.1.3 Duty of candour in judicial review – Huddleston, Shao, RAS Medical

On the duty of candour, the Court relies on the well-known English authority R v Lancashire County Council ex parte Huddleston [1986] 2 All E.R. 941. In that case, the court described the obligation of a public law respondent in judicial review as follows:

the respondent must put “all the cards face upwards on the table” because “the vast majority of the cards will start in their hands”.

O’Higgins J notes that this dictum:

  • has been expressly approved in Ireland, including in Humphreys J’s decision in Shao v Minister for Justice (No. 2) [2020] IEHC 68; and
  • is also referenced in the Supreme Court’s decision in RAS Medical v Royal College of Surgeons [2019] IESC 4.

The judge regards this as a “key principle of modern day judicial review jurisprudence”. Public bodies, because they control most of the relevant information, owe a duty of candour and cooperation that goes beyond the strict minimum of discovery.

However, EirGrid did not dispute the existence or importance of this duty. The question was whether, on the facts, it had been breached in a manner warranting exceptional costs.

6.1.4 The general costs framework – Little v Chief Appeals Officer [2024] IESC 53

Although primarily concerned with the solicitor–client costs jurisdiction, the Court, when addressing the “costs of the costs application”, referenced the Supreme Court’s approach in Little v The Chief Appeals Officer [2024] IESC 53 (Murray J).

That decision reinforces the principle that:

  • costs follow the event remains the starting point; but
  • the court has a broad discretionary power—under statute and rules of court—to depart from that starting point where the interests of justice so require.

O’Higgins J’s resolution—no order as to costs on the motion despite EirGrid’s success— is an application of that flexible, justice-based approach.

6.2 The Competing Narratives on Alleged Non-Disclosure

6.2.1 Kilshane’s case: withheld “actual reasons” and ulterior motives

Mr Draffin’s affidavit crystallises Kilshane’s complaint. Having read the EirGrid report submitted on remittal, he averred that EirGrid:

  • withheld crucial information about its reasons and motivations for refusing to qualify the candidate units, up to 13 December 2024;
  • for the first time, contended that connecting Kilshane’s project would negatively impact its own projects, suggesting that EirGrid saw itself as in direct competition with generators for transmission capacity; and
  • had ulterior motives, namely to prioritise and “advantage” its own grid reinforcement projects, rather than applying the Capacity Market Code’s feasibility criteria neutrally.

Particular emphasis was placed on the “new” matters in paragraph 3.1.3 of the EirGrid report:

  • absence of a provision for Kilshane’s connection at Woodland under project CP1194 (Woodland Station Redevelopment);
  • the need for additional land acquisition, a new bay and planning consent at Woodland;
  • potential impacts on three strategic reinforcement projects: Kildare–Meath, East Meath–North Dublin (EMND), and the North–South Interconnector; and
  • their status as priority projects in EirGrid’s Grid Delivery Portfolio.

Kilshane argued:

  • these reasons could and should have been disclosed at least as early as 16 August 2024 (the provisional qualification decision);
  • they were plainly central to EirGrid’s thinking and therefore central to the judicial review issues; and
  • by withholding them until after the Court’s oral ruling, EirGrid breached the duty of candour, warranting an exceptional costs sanction to mark the Court’s disapproval.

Notably, Mr Draffin expressly declined to speculate on how earlier disclosure would have changed the argument or outcome in the substantive proceedings, but he asserted that at least the Court should take EirGrid’s failure into account when determining the basis of costs.

6.2.2 EirGrid’s response: explanation and rejection of “ulterior motives”

Mr Farrell’s affidavit contained EirGrid’s detailed rebuttal:

  • The EirGrid report was prepared solely to assist the SEMC (Single Electricity Market Committee) in its reconsideration of the remitted Final Qualification Decision (FQD).
  • The report explicitly stated that it responded to new information provided by Kilshane on 13 December 2024, including:
    • a memorandum and supporting materials; and
    • the H&MV Engineering report and route map (12 December 2024).
  • Section 2 of the report indicated that EirGrid drew on its experience with major 400kV reinforcement projects, including Kildare–Meath and EMND, as comparators—projects already referenced in the earlier CMDRB hearing.
  • EirGrid firmly refuted the suggestion that it:
    • was in competition with generators; or
    • harboured ulterior motives to promote its own projects.
    Rather, it emphasised its statutory duties as TSO to ensure the security and development of the transmission network.
  • The further obstacles identified in the EirGrid report (including the interference between Kilshane’s proposed route and the EMND project) arose because Kilshane’s new route map, provided only on 13 December, for the first time disclosed the alignment in question.
  • Any differences between earlier documentation and the EirGrid report were said to be no more than nuanced description or analysis responding to new technical data, rather than new hidden reasons.

EirGrid’s position, in essence, was that:

  • there was no deliberate or wrongful non-disclosure;
  • the refusal ground remained the same—feasibility within the required timeframe;
  • there was no breach of the duty of candour; and
  • in any event, the stringent preconditions for solicitor–client costs were not satisfied.

6.3 The Court’s Evaluation of the Alleged Non-Disclosure

6.3.1 Recognition of “new reasons” and an “adjusted focus”

O’Higgins J is careful and balanced in assessing the materials:

  • He accepts that there is some basis for saying that new reasons appear in the EirGrid report, and that there is an adjusted focus, particularly regarding the need to expand Woodland Substation, associated planning issues, and implications for other grid projects.
  • He acknowledges that the applicant has a point in complaining that the earlier focus, both before the CMDRB and in the substantive proceedings, was on the difficulties of constructing the cable connection itself, rather than the substation expansion and its interactions with other projects.

Thus, the Court does not characterise Kilshane’s concerns as fanciful: there were genuine differences of emphasis and additional information in the later report.

6.3.2 But is that enough to prove wrongful non-disclosure?

The key question, in the judge’s words, is whether this altered emphasis or additional information establishes a “wrongful or blatant withholding of relevant information”. He concludes that it does not, for several reasons:

  1. Context of new information from Kilshane
    Kilshane itself, during the remittal, submitted additional materials that were not before EirGrid or the Court previously. The EirGrid report opened by noting that some of this was new or an expansion of earlier information. It was therefore natural and necessary for EirGrid to respond with an updated assessment.
  2. Same overarching refusal ground: feasibility
    Although the emphasis shifted in some respects (from cable construction to substation expansion and project interactions), the core ground of refusal—feasibility within the required timeframe—remained constant. This continuity weighed against characterising the later material as a concealed, alternative set of reasons.
  3. Affidavits not directed to alleged non-disclosure
    The affidavits filed in the substantive proceedings had not been framed to address an allegation of non-disclosure. They were directed at defending and attacking the refusal decision as presented at the time. The judge warns against over extrapolating from what those affidavits did or did not say, or reading too much into omissions that were never at issue then.
  4. Different focus of earlier arguments
    Much of the earlier evidence and submissions related to the CMDRB hearing, which had a different focus from this subsequent costs application. That procedural and argumentative context cannot be ignored.
  5. Time pressure and truncated timelines
    The EirGrid report was prepared under acute time pressure—shortly before midnight on 13 December 2024— within a tightly truncated schedule imposed by the need to hold the capacity auction. All parties were under similar pressure. While not a “get out of jail” card, this context made it less plausible that EirGrid was engaged in a calculated strategy of concealment.
  6. No clear-cut evidential basis; caution about inference of motives
    The judge stresses that the case law requires the court to be slow to infer misconduct in the absence of clear-cut evidence, especially where:
    • the moving party invites the court to interpret documentation, draw inferences about motives, and effectively find serious wrongdoing without oral evidence.
    O’Higgins J is explicit that he is not laying down a rule that oral evidence is always required in such applications. Rather, on these facts, the documentary evidence did not clearly prove a wrongful, deliberate withholding.
  7. The “consequences” requirement not satisfied
    Drawing expressly on principle 6(c) and 7 from Trafalgar, the judge emphasises the need to demonstrate consequences—serious prejudice—in order to justify solicitor–client costs. He concludes that this “consequences leg” of the test has not been proved to the required standard. Kilshane did not identify specific delay, extra cost, or substantive disadvantage caused by the alleged non-disclosure. Indeed, its deponent expressly refrained from speculating about what difference earlier disclosure might have made.
  8. High threshold for exceptional costs
    Finally, the Court returns to the requirement that only particularly serious or blatant breaches with serious consequences can justify departure to solicitor–client costs. Taking all factors cumulatively, the threshold was simply not reached.

6.3.3 No proven breach of candour sufficient to trigger exceptional costs

The Court therefore:

  • does not make a definitive finding that there was a breach of the duty of candour; rather, it finds that the alleged non-disclosure has not been proved to the standard required; and
  • even if there were imperfections in disclosure, they fall short of the category of particularly serious or blatant misconduct, with serious consequences, which can attract solicitor–client costs.

On that basis, the Court refuses the application for solicitor–client costs.

6.4 The Duty of Candour: Reaffirmed but Constrained

A notable feature of the judgment is its dual stance on the duty of candour:

  • On the one hand, O’Higgins J strongly endorses Huddleston and its Irish progeny, describing the duty of candour and cooperation as a key principle of modern judicial review, particularly applicable to public bodies holding most of the relevant information.
  • On the other hand, he is equally clear that:
    • not every omission or later elaboration amounts to a breach of that duty; and
    • even where one might argue that disclosure could have been more complete, this does not automatically trigger costs sanctions on the solicitor–client basis.

The judgment thereby distinguishes between:

  • the duty of candour as a substantive and procedural obligation in judicial review (relevant to the granting of relief and to how courts evaluate administrative decision-making); and
  • the separate, exceptional question of whether a particular shortcoming justifies punitive or exemplary costs orders.

In practice, the decision signals that:

  • serious breaches of the duty of candour may justify quashing decisions, remittals, or other substantive relief; but
  • only a subset of such breaches—those proved to be egregious and seriously prejudicial— will justify solicitor–client costs as a form of judicial censure.

6.5 Costs of the Costs Application

6.5.1 EirGrid’s argument: costs should follow the event

EirGrid, having successfully resisted the solicitor–client costs application, relied on:

  • the statutory framework (including the Legal Services Regulation Act 2015) and the general costs follow the event principle; and
  • a warning letter from its solicitors (Matheson) of 15 May 2025, which:
    • set out EirGrid’s position; and
    • indicated that if Kilshane persisted with its application and failed, EirGrid would seek its costs of the motion.

There was a clear “event” for costs purposes: the refusal of the application for enhanced costs. On a straightforward application of the usual rule, EirGrid was therefore entitled to its costs of the motion.

6.5.2 The Court’s reasons for departing from “costs follow the event”

While acknowledging that EirGrid had “carried the day”, the Court held that there was a proper basis to depart from the usual rule, though not to reverse it entirely. The factors influencing this discretion included:

  • The Court’s earlier finding that there was some justification for Kilshane’s concerns:
    • the EirGrid report did contain new matters and an adjusted focus; and
    • EirGrid’s affidavit explicitly acknowledged that the report had identified further obstacles to feasibility (albeit in response to new information from Kilshane).
  • The application was not “wholly baseless” or vexatious; it was a serious argument grounded in objective features of the post‑remittal documentation.
  • The Court had felt it necessary, in the interests of fairness and cautious procedure, to allow the issues to be properly ventilated.
  • While the application ultimately did not meet the high threshold for exceptional costs, it did raise genuine questions about the interplay between the duty of candour and the remittal process.

Balancing these considerations with:

  • the principle in Little that costs follow the event is a starting point, not an inflexible rule; and
  • the further objective of avoiding unnecessary exacerbation of tensions between parties (“not pouring salt onto wounds”),

the Court determined that no order as to costs on the motion was the just outcome.

7. Complex Legal Concepts Explained

7.1 Party–Party vs Solicitor–Client Costs

  • Party–party costs (the norm):
    • are intended to compensate the successful party for costs reasonably and proportionately incurred in the litigation;
    • do not usually cover every item on a solicitor’s bill; and
    • represent a partial indemnity, reflecting the court’s view of what was necessary and appropriate.
  • Solicitor–client (legal practitioner and client) costs:
    • are more generous, closer to a full indemnity of what the client owes its solicitor;
    • are exceptional, reserved for cases where the losing party’s conduct warrants judicial censure;
    • are often ordered to mark disapproval of misconduct such as serious discovery breaches, abuse of process, or reckless allegations.

In this case, Kilshane already had party–party costs of its successful judicial review. It sought to “upgrade” them to solicitor–client on the basis of alleged serious misconduct by EirGrid. The Court declined to do so.

7.2 Duty of Candour in Judicial Review

The duty of candour is a doctrine developed in public law that recognises:

  • information asymmetry: public bodies hold most of the relevant documents and knowledge about their decisions;
  • therefore, to allow the court to perform effective supervisory review, those bodies must be frank and open in explaining how and why decisions were taken.

The Huddleston metaphor—“all the cards face upwards on the table”—means:

  • public respondents must not selectively disclose only what assists them;
  • they must proactively disclose material that might assist the court and the applicant, even if it weakens their case;
  • the duty is to the court, not just to the other side.

This does not mean that any later clarification or elaboration of reasons is automatically a breach. The key questions are:

  • Was important, relevant information withheld without justification?
  • Was this done deliberately or recklessly?
  • Did it meaningfully affect the fairness or outcome of the proceedings?

7.3 Remittal and the Capacity Market Context

  • Remittal:
    • When a court quashes an administrative decision, it often remits the matter to the decision-maker to reconsider it in accordance with the court’s judgment.
    • In this case, the CRU was required to reconsider Kilshane’s qualification application within a compressed timeframe.
  • FQD (Final Qualification Decision):
    • The formal decision as to whether a candidate unit is qualified to participate in the capacity auction.
  • CMDRB (Capacity Market Dispute Resolution Board):
    • A body that hears disputes concerning qualification decisions under the Capacity Market Code.

The remittal process in this case was complicated by:

  • tight deadlines linked to an imminent capacity auction; and
  • the need for rapid exchanges of new technical information between Kilshane, EirGrid and the CRU.

7.4 Feasibility and Planning Conditions

The dispute about “feasibility” concerned:

  • whether Kilshane could deliver a fully operational 400kV grid connection from Huntstown to Woodland in time for the capacity auction period; and
  • how that connection interacted with:
    • existing and planned grid reinforcement projects; and
    • planning constraints, including local authority conditions and An Bord Pleanála approvals.

EirGrid’s later focus on:

  • the need for Woodland substation expansion and a new bay;
  • land acquisition and planning consents; and
  • the priority status of parallel projects (Kildare–Meath, EMND, North–South Interconnector),

underpinned Kilshane’s assertion that EirGrid’s “true” reasons involved prioritising its own projects. The Court, however, accepted EirGrid’s explanation that these issues crystallised in response to new route information and did not conclusively demonstrate an ulterior motive or breach of candour.

8. Impact and Significance

8.1 For Public Bodies in Judicial Review

The decision is a reminder that:

  • Public bodies must observe the duty of candour and should strive to lay out their reasoning fully and frankly.
  • However, courts will be cautious about finding serious misconduct justifying solicitor–client costs:
    • isolated imperfections or changes in emphasis will rarely suffice;
    • context (time pressure, remittals, evolving information) matters; and
    • courts will look for clear, specific evidence of deliberate or reckless withholding.

For public bodies, the safe course remains:

  • to document and disclose all material reasons at the earliest stage; and
  • to ensure internal communications and external memoranda can be defended as candid, consistent and complete.

8.2 For Litigants Seeking Enhanced Costs

For applicants considering motions for solicitor–client costs based on alleged non-disclosure, this case underlines:

  • You must:
    • pinpoint the alleged misconduct with specificity (what exactly was withheld or misstated);
    • provide a convincing answer to the respondent’s explanation; and
    • demonstrate concrete prejudice—e.g. that the non-disclosure caused you to incur additional steps, delayed the proceedings, or impaired your ability to present your case.
  • Subjective interpretations of documents and allegations of ulterior motives will not suffice without robust evidential support.
  • Courts are wary of transforming every dispute about reasoning or disclosure into a platform for punitive costs orders.

8.3 For Electricity and Regulatory Law

Although formally a costs decision, the judgment has practical implications in the electricity regulation context:

  • It implicitly recognises that grid connection feasibility assessments may engage a complex matrix of:
    • technical feasibility;
    • timing and project delivery risk; and
    • interactions with other high‑priority grid reinforcement projects.
  • Accusations that a TSO is in competition with generators and abuses its position to favour its own projects will be scrutinised carefully, and must be supported by clear evidence rather than inference alone.
  • The Court’s refusal to infer ulterior motives based solely on a later elaboration of technical obstacles may moderate the tone of future challenges and focus them more squarely on documentary and factual proof.

8.4 Development of Costs Jurisprudence

The decision fits within, and slightly extends, the Irish jurisprudence on costs by:

  • reaffirming the Trafalgar framework and its adoption by the Supreme Court in Gaelscoil Moshíológ;
  • clarifying that the “consequences” limb in principle 6(c) is not an afterthought, but a substantive requirement for solicitor–client costs; and
  • illustrating, via the “no order as to costs” outcome on the motion, the nuanced application of Little-style discretion even where one party is clearly successful.

In that sense, Kilshane (No. 2) stands as an illustrative authority on the limits of enhanced costs orders as a mechanism for policing alleged breaches of the duty of candour.

9. Conclusion

Kilshane Energy Limited v EirGrid plc (No. 2) [2025] IEHC 710 provides a careful, structured application of Irish costs principles in the context of judicial review against a public utility. It does not revolutionise the law, but it meaningfully clarifies that:

  • while the duty of candour is a central feature of modern judicial review, its breach must be clearly proved and shown to have serious consequences before exceptional solicitor–client costs will be ordered;
  • changes in emphasis or additional reasoning disclosed in a remittal process—especially where they respond to new information and are produced under time pressure—will not, without more, be treated as evidence of wrongful concealment;
  • the “consequences” requirement in the Trafalgar principles is real and demanding: applicants must show concrete prejudice, not merely assert that non-disclosure could hypothetically have mattered; and
  • even where an application for enhanced costs fails, if it raised genuine issues on a reasonable basis, the court may temper the strict “costs follow the event” rule and, as here, make no order as to costs on the motion itself.

The judgment thus solidifies the high bar for awarding solicitor–client costs in Irish judicial review, particularly where such orders are sought as a sanction for alleged breach of the duty of candour. It emphasises evidential rigour, contextual sensitivity, and a measured use of the costs jurisdiction to police litigation conduct.

Case Details

Year: 2025
Court: High Court of Ireland

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