Case number: OIC-55325-H1J6D8

Whether EirGrid was justified in refusing access to copies of the single line diagrams of electrical substations under section 32 of the FOI Act

25 October 2019


In a request dated 26 March 2019, the applicant sought access to a copy of “the single line diagrams for the existing 110kv and 220kv substations in the Republic of Ireland”. In a decision dated 15 April 2019 EirGrid refused the applicant’s request under sections 32(1)(b) and 32(1)(c) of the FOI Act. The applicant sought an internal review of that decision, following which Eirgrid affirmed its original decision. The applicant sought a review by this Office of EirGrid’s decision on 25 July 2019.

I have now completed my review of EirGrid’s decision. In conducting the review, I have had regard to the correspondence between EirGrid and the applicant as outlined above and to correspondence between this Office and both EirGrid and the applicant on the matter. I have also had regard to the contents of the records at issue.

Scope of Review

This review is concerned solely with whether EirGrid was justified in refusing access to copies of the single line diagrams of electrical substations under sections 32(1)(b) and 32(1)(c) of the FOI Act.

Preliminary Matter

In his correspondence both with Eirgrid and with this Office, the applicant explained why he wants access to the single line diagrams and how he intends to use the information contained within the records. I note that Eirgrid has argued that access to the records in question would not serve the purposes proposed.

Regardless, it is important to note at the outset that section 13(4) of the Act provides that in deciding whether to grant or refuse a request, any reason that the requester gives for the request shall be disregarded. This means that this Office cannot have regard to the applicant's motives for seeking access to the information in question, except in so far as those motives reflect what might be regarded as public interest factors in favour of release of the information where the Act requires a consideration of the public interest.

Analysis and Findings

Having regard to the nature of the submissions made by Eirgrid during the review, I am of the view that section 32(1)(c) is of most relevance in this case. Therefore, I will first consider the applicability of that section to the records at issue.

Section 32(1)(c) provides that an FOI body may refuse to grant a request if it considers that access to the record concerned could reasonably be expected to facilitate the commission of an offence. Where an FOI body wishes to rely on section 32(1)(c), it should explain how the release of the particular record could make it easier to commit an offence and why it considers its expectation of the harm occurring to be reasonable.

It is important to note that the release of record(s) under FOI is regarded as release to the world at large, given that the Act places no restrictions on the uses to which information released under the Act may be put. As such, when considering the applicability of section 32(1)(c), the question is not whether release would facilitate the applicant in the commission of an offence but rather whether release would facilitate the commission of an offence by any party.

In its original decision Eirgrid stated its refusal to grant the request was based on its decision to restrict and control the dissemination of detailed information relating to the electricity network due to the risk posed to the integrity and security of the network. It argued that providing detailed line diagrams or sketches could facilitate the theft of copper or endanger the supply of electricity.

In his application for internal review, the applicant argued that the technical information in the records provides no indication pertaining to the location or quantity of copper for theft in a substation. He argued that publicly available information on sources such as Google Earth, Bing Maps and Google Street view provide exact locations of equipment within substation compounds that could facilitate the theft of equipment to a much greater extent than single line diagrams for substations. He further argued that considering other publicly available network information from EirGrid’s publications like the 2017 Transmission Forecast Statement and planning consent information on County Council and An Bord Pleanála websites, he does not believe there would be any increased security threat to the transmission system from single line diagrams being made available.

In its submissions of 1 October 2019 to this Office, EirGrid said that the High Voltage electricity transmission network in Ireland is critical national infrastructure. It said the network is comprised of the High Voltage overhead lines, underground cables, and substations used to connect generation and demand. It argued that it is vital that EirGrid, as the prudent operator of this essential service, controls access to operational details.

EirGrid argued that placing the transmission system single line diagrams into the public domain is the equivalent of publishing a detailed, comprehensive, and coordinated source of information describing the electricity infrastructure of the country. It argued that having this information available facilitates the targeting of specific network assets and may enable the criminal targeting of key elements to undermine the integrity/security of the entire power system. It said there is also a risk of exposing major population centres and specific industrial facilities / major corporations to targeted attack. It said power outages could be initiated directly at specific stations or from neighbouring stations.

EirGrid went on to say that while Google Maps and similar applications do, indeed, indicate the locations of some substations they do not provide it on a systematic basis since some stations are built indoors and are not readily identifiable as transmission system infrastructure. It said Google maps will not show the connections between stations. It argued that it would be challenging to build up a cohesive view of the station and its connectivity with the wider network with online mapping services, whereas the set of single line diagrams will show the primary equipment at each location, the internal connectivity, connections to other stations and by implication, its strategic role/position in the power system.

EirGrid added that by their very nature, single line diagrams also contain information regarding third party installations which should not be put in the public domain. It said whilst it would be possible to redact identifying customer information from the diagrams, it would still be straightforward to identify the protected party using other information such as station name and names of the circuits connected to the station.

I accept Eirgrid’s argument that the availability of the single line diagrams would facilitate the criminal targeting of specific network assets and or key elements to undermine the integrity/security of the entire power system. As such, I am satisfied that release of the single line diagrams could reasonably be expected to facilitate the commission of an offence. I find that section 32(1)(c) applies.

Section 32(1) is subject to section 32(3) which provides that consideration must be given to the possibility that the public interest would be better served by the release of the information rather than it being withheld, in the event that any one of three specific conditions apply. I am satisfied that none of the conditions set out in section 32(3) apply in this case. As such, the question of where the balance of the public interest lies does not arise.

In conclusion, therefore, I find that Eirgrid was justified in refusing the applicant’s request for copies of the single line diagrams of electrical substations under sections 32(1)(c) of the FOI Act. Having found that section 32(1)(c) applies, I do not need to consider the applicability of section 32(1)(b) to the records.


Having carried out a review under section 22(2) of the FOI Act, I hereby affirm the decision of EirGrid to refuse access to records of single line diagrams of electrical substations under section 32(1)(c) of the FOI Act.

Right of Appeal

Section 24 of the FOI Act sets out detailed provisions for an appeal to the High Court by a party to a review, or any other person affected by the decision. In summary, such an appeal, normally on a point of law, must be initiated not later than four weeks after notice of the decision was given to the person bringing the appeal.



Stephen Rafferty
Senior Investigator