Dublin, 29 January
Yesterday, in response to EirGrid’s recent public
consultation process, I announced that I have appointed an independent panel of
experts, to be chaired by Mrs Justice Catherine McGuinness, to decide terms of
reference for comprehensive, route-specific studies of fully underground options
for both Grid Link and Grid West.
Studies of the overhead and underground options
will then be published side-by-side, in objective and comparable terms, before
proceeding to the next stage of public consultation on those two projects.
The two studies will take account of
environmental (including visual amenity) impacts, technical efficacy and cost
The independent panel will have power to
commission its own work if there is any perceived deficiency in the studies
Three matters have subsequently arisen which I
believe need some clarification.
First, I would stress that the expert
panel will not be asked to express a preference or to make any recommendations
in relation to overhead or underground options. Rather, they will be asked to
ensure that the underground studies are complete and objective, and are
comparable to similar studies of overhead options for the two projects. In
effect, the panel will certify the integrity of the process, with the
commissioned material being put out for public debate and, ultimately, for
consideration and decision by the planning authorities.
Second, I would emphasise that the
electro-magnetic fields (EMF) issue will not fall under the remit of the expert
panel. Responsibility for this rests with the Department of Environment,
Community and Local Government. Minister Phil Hogan agreed yesterday that he
will engage expert assistance to review and report on international developments
in the scientific literature on potential health effects of EMF emanating from
transmission grid infrastructure. It is anticipated that this study will provide
the best available information on:
published, peer reviewed scientific literature
relating to non-ionising radiation and associated epidemiological matters,
work carried out under, and findings of,
relevant international bodies, as well as
relevant international and national standards
and guidelines covering the period 2007 to date.
The study will serve as an update on a report,
“Health Effects of Electromagnetic Fields”, which was produced by my Department
In that regard, I want to emphasise that the best
advice available to EirGrid and to me is that there have been no developments
since 2007 which would give cause for concern regarding the health effects of
Therefore the issue of placing an expert in this
area on the McGuinness panel does not arise.
Third, as I’ve said, my response yesterday
was to the Grid Link and Grid West projects. The arrangements relating to the
North South transmission line are different for several reasons. The reality is
that planning for this project has been underway for the last 10 years. A
planning application has already been submitted for the part of the project in
Northern Ireland and that planning process is in train.
Detailed studies have already been conducted for
the project, most recently by the Independent International Commission of
Experts appointed in July 2011, arising from a commitment in the Programme for
Government. And a route-specific underground analysis was conducted by PB Power,
which found that the cost of undergrounding would significantly exceed the cost
of the more usual overhead cables. The PB Power analysis was considered and
confirmed by Independent Commission, who estimated that the cost of
undergrounding would be at least three times that of overhead cables.
The North-South transmission line is a critical
and strategically urgent transmission reinforcement and is of critical
importance in the broader North-South context. This is because, as well as
reinforcing the grid in the North East region of the State, the transmission
line will be a vital link in maintaining the security of electricity supply for
Northern Ireland into the future.
I recognise, however, that the public would be
reassured if they knew that the overhead and underground options for North South
have both been investigated and that the already published studies are
sufficient to enable a similar comparison be made by Bord Pleanála when they
come to decide on the merits of this planning application.
I am meeting the chair of the independent panel,
Mrs Justice Catherine McGuinness, this coming Friday to discuss the work
programme for the panel. Before yesterday’s Cabinet meeting the Taoiseach asked
me and I agreed that I would ask Judge McGuinness to consider what work if any
her panel might usefully undertake to establish that there has been parity of
treatment between the North South project, in terms of the work undertaken to
date, and Grid link and Grid West, in terms of the studies that are now
proposed. This is of course a matter for decision by Judge McGuinness and her
I am attaching to this statement a summary of
significant factors relating to the North South project.
The North South Transmission Line
The North South transmission line is a high
capacity line linking the existing substation in Woodland, Co. Meath with a
planned substation in Turleenan, Co.Tyrone. It is a critical and strategically
urgent transmission reinforcement. The Ireland and Northern Ireland electricity
markets are merged and form the all-island “Single Electricity Market” (SEM).
While established and operating outside the context of the Good Friday Agreement
and its attendant institutions, the SEM is perhaps the single most significant
example of smooth and seamless North-South cooperation, at legislative,
governmental and regulatory level, in the joint management of a key sector of
our economic and industrial infrastructure.
The transmission line is vital in giving an
infrastructural underpinning to the SEM. While there is an all-island market in
place, lack of interconnection curtails the full benefits of that market being
Currently there is only one high capacity
transmission line between the electricity transmission networks of Ireland and
Northern Ireland. The benefits of this arrangement are restricted by the
significant risk of separation and consequent destabilisation of the two
systems; by the physical capacity of the existing line; by planned and unplanned
outages; and by the need to allow for unexpected changes in generation and
demand. These risks will be significantly reduced by construction of the second
North South transmission line, which will provide a separate power flow
independent of the existing transmission line.
Further, the reality is that the SEM is not
delivering full benefits to consumers and cannot do so unless the North South
transmission line is delivered. This is because, without the line, the least
cost generators cannot run and more expensive generators have to be scheduled.
The cost of less expensive plants not running, called constraint cost, is shared
equally across all consumers on the island. The associated constraint costs are
adding €20m to €30m to all-island consumers’ bills for every year of delay to
the project. Neither Grid Link nor Grid West is as critical to the proper
functioning of the SEM or to the security of the all-island electricity
The Irish electricity system is an alternating
current (AC) system. That is to say, power is generated, transmitted,
distributed and, ultimately, consumed on an AC basis. It is possible to
underground an AC cable for a short distance (a few kilometres), to cope with
areas of high amenity, for example. But, if a power cable is to be undergrounded
for any greater length, then the only option is to convert the power to direct
This requires, at a minimum, the installation of
converter stations at both ends of the undergrounded line, each of them larger
than Croke Park’s pitch and nine storeys tall. It also means that, if it is
decided now or in the future to make a branch from the DC line, to meet energy
needs along the route of the line, then another converter station must be
installed, at a cost five times more than branching from an AC line.
In addition to these considerations, installation
of DC power gives rise to operational difficulties. In other words, it is one
thing to ship power from one grid to another grid via a high voltage DC cable.
It is, however, quite another matter to install a DC transmission line as the
North-South ‘spine’ that is intended to lead to a single, integrated, all-island
AC transmission and distribution system.
A power system is like a living creature with the
AC lines and cables acting as its nervous system. Any problem or disturbance,
like a lightning strike or generator trip, is instantly felt throughout the AC
system and it naturally responds to keep the system stable. This natural
behaviour of AC systems is how it is possible to provide electricity, with
millions of constant changes, reliably to customers. The larger the AC system,
the more stable it is and the less reserve, (which costs money) is needed. DC
connections are operated by computer based control systems and are very
effective at moving power but they do not have the natural response to problems
that AC systems do.
Between Northern Ireland and Ireland there is
already one AC connection and engineers must keep enough reserve available to
protect consumers if this line has a fault: a second AC line would remove this
need and allow the two systems to act as one, delivering important potential
efficiencies and savings for customers. While a new DC connection would allow
extra trade, it would not allow the two systems to act as one and so the major
benefits of lower reserves and increased security would not be fully
Northern Ireland’s supply needs
The construction of the North South transmission
line is also of critical importance in the broader North-South context. As well
as reinforcing the grid in the North-East region of the State, with the
attendant benefits for industry and consumers, the transmission line is a vital
link in maintaining the security of electricity supply for Northern Ireland into
the future. Northern Ireland is facing an increased risk to security of supply
from 2016 onwards if the North South project is not delivered. Thus, further
delays to its construction are a security of supply issue for Northern Ireland
as well as an issue of increased costs.
It needs also to be borne in mind that the North
South transmission line will cover 100km of line south of the border and 40km
north of the border. The project requires a common engineering approach and,
therefore, any decision to elect for an underground option south of the border
would impose a similar solution north of the border, and the attendant
additional costs on Northern Ireland consumers.
Planning for the North South transmission line
has been underway for the last 10 years. A planning application has already been
submitted for the part of the project in Northern Ireland and that planning
process is currently in train.
Detailed studies have already been conducted for
the project, most recently by the Independent International Commission of
Experts appointed in July 2011 which reported in February 2012. EirGrid has
taken full account of the contents of those studies in finalising the planning
application which is expected to be lodged shortly with An Bord Pleanála. The
project is an entirely alternating current (AC) overhead design.
The report of the Independent Commission arose
from the commitment contained in the Programme for Government to review the case
for, and cost of, undergrounding all or part of the proposed Meath-Tyrone
transmission line. An earlier route-specific underground analysis was conducted
by PB Power, which found that the cost of undergrounding would significantly
exceed the cost of the more usual overhead cables. The PB Power analysis was
considered and confirmed by Independent Commission, which estimated that the
cost of undergrounding would be at least three times that of overhead
While numerous other studies had already been
completed internationally with regard to undergrounding generally, in 2009 the
then Minister for Communications, Energy and Natural Resources commissioned an
independent study on Comparative Merits of Overhead Electricity Transmission
Lines versus Underground Cables. That study was conducted by international
consultants Ecofys, and it concluded that underground cables do not compare
favourably to overhead lines in terms of adequacy of the electricity
The study also noted that internationally,
overhead lines are the standard choice for high voltage transmission
connections. This remains the case today in that high voltage lines which are an
integral part of transmission systems, such as the line planned for
Meath-Tyrone, are almost always overhead as indicated in the table below.
|Country||400kV Overhead Line (km)||400kV Underground Cable (km)||% Cable|
|Note: Since the figures above were
compiled a small section of 400kV network has been implemented in Ireland
related to the East West Interconnector in
The Independent Commission reviewed the various
reports relating to the Meath-Tyrone project, as well as international projects
which the members considered were pertinent, and also reviewed previously
published studies on the underground versus overhead issue.
The report noted that new high voltage direct
current (HVDC) technology was a feasible technical solution, implemented as
underground cable, for the Meath-Tyrone project but estimated that the cost of
implementing the project as an underground cable option would be three times the
cost of the classical overhead line option. In addition, inserting a DC line
into a single, meshed AC system would have system operation implications. The
Commission did not recommend any particular technical option but provided its
own assessment of the feasible technology options available for consideration
for the project in the context of changes in technology, suppliers and costs in
recent years. The Commission noted that there is no single ‘right’ solution and
that technical solutions must be project specific.
Finally, it is worth noting that, as an
interconnecting transmission line between two EU Member States, the project has
been designated by the European Commission as a Project of Common Interest (PCI)
and therefore deemed subject to EU Regulation No. 347/2013. Article 7 of the
Regulation states that “projects of common interest shall be considered as being
of public interest from an energy policy perspective, and may be considered as
being of overriding public interest”. It places an obligation on the Member
States involved, in this case Ireland and the UK, to consider the project to be
of the “highest national significance possible and be treated as such in permit
granting processes”. It further requires that “all authorities concerned shall
ensure that the most rapid treatment legally possible is given” to the any
applications for consent.