JOINT COMMITTEE ON COMMUNICATIONS, ENERGY AND NATURAL RESOURCES díospóireacht -
Tuesday, 22 Jul 2008

Electricity Transmission Infrastructure: Discussion with ECOFYS Consultants.

Chairman

I welcome Dr. Karsten Burges, manager of ecofys Consultants, and Mr. Conor Wall and Mr. Bill Sheridan of Golder Associates. The purpose of the meeting is to discuss ecofys's recently published study of the comparative merits of overhead electricity transmission lines versus underground cables. The study was initiated in February following calls from this committee for an independent analysis of the issues relating to both types of transmission infrastructure. We are pleased the Minister agreed to our request.

This meeting affords the committee a further opportunity to discuss the merits of overhead lines versus underground cables in a constructive way and from the perspective of the various stakeholders, with reference to specific projects such as the Tyrone-Monaghan-Meath connection, which project comes within the remit of the strategic infrastructure legislation and on which a final decision will rest with An Bord Pleanála. It is not the objective of this meeting to discuss any particular routes but rather to consider the findings of the study and place the facts in the public arena.

I remind delegates that while members of the committee have absolute privilege, the same privilege does not apply to witnesses appearing before the committee which cannot guarantee any level of privilege to witnesses. Under the salient rulings of the Chair, members should not comment on, criticise or make charges against a person outside the Houses or an official by name or in such a way as to make him or her identifiable.

I invite Dr. Burges to make his presentation.

Deputy Liz McManus

There is a great deal of public interest in this issue. Surely interested members of the public should be permitted to enter the committee room for this discussion.

Chairman

The usher has been notified to invite members of the public into the committee room.

Dr. Karsten Burges

A couple of days ago members received a fairly extensive report dealing with the comparative merits of overhead lines and underground cables and the committee has invited us to answer the questions which the report may have left open. I am convinced there are many questions which cannot be covered in detail in a report such as this.

I will start by making a statement which may appear trivial. All societies rely on electricity and electricity needs infrastructure. We state in the report that any infrastructure has an impact, on the economy, on people and on the environment. The nature of these impacts and their comparative analysis are what we tried to clarify in the report. I will highlight five of the key topics we found and, after the presentation, we will be happy to answer questions which touch on other issues not covered by reason of the limited timeframe.

The study, in accordance with its scope, covered two components. One was an extensive analysis of a significant number of submissions delivered to the Department and thence to us to review. The other component was an expert review of the state of the art of underground cabling and overhead line technology. The difference between the two components is not only that one covers the public perception of those technologies while the other is an expert view but also that the submissions dealt with a specific project under planning and development in Ireland at the moment, whereas the expert review was intentionally a generic exercise, dealing with transmission technologies as they are available at present.

Having reviewed the 522 submissions we came to a number of key conclusions. The most important was the fact that public concern mostly related to the impact of a transmission project on communities, particularly as it related to health, property values and visual impact. It may have been as expected that far fewer submissions related to the technical nature of the technologies and this is what the consultants added. The findings of the analysis were used in the report to make sure the technology evaluation covered all the issues raised by the submissions.

One of the key concerns relates to environmental issues. Members would agree that both overhead lines and underground cables have an impact in implementation on their local environment. The degree and nature of this impact varies by technology and on a case by case basis, depending on the local circumstances.

One of the key messages found in the report is that these impacts must be mitigated as well as possible, which should be done from the very beginning when designing such an infrastructure. This requires a holistic understanding of the nature of such a project and the nature of the impacts in order to achieve balance. It is an optimisation process which requires compromises in order to balance these impacts in the best available way.

Related to community impacts, one of the most important issues raised in the submissions is the exposure of people in the area to magnetic fields. In the report there is a graph showing the strength of electromagnetic fields for various conductive arrangements, with the black lines signifying overhead lines and the blue lines signifying underground cables. The I/x axis arrangement indicates the strengths of the magnetic field for a certain arrangement. The design of a transmission line has a significant impact on the magnetic field felt in the environment.

The strengths of the magnetic field of an underground cable circuit is highly concentrated to the cable corridor. The magnetic fields related to overhead lines spread out a bit more along the lines. One can still see that an arrangement with underground cables which are quite distant from each other for technical reasons may have very high levels, whereas a suitable design of overhead lines - we can see the design proposed by EirGrid - ends up with magnetic field strengths which are on the same order of magnitude as those of underground cables. The message is that the effects can be mitigated if they are taken into account from the very beginning.

As consultants, we also took into account aspects which must be considered when evaluating these technologies, as well as in terms of numbers of submissions. One of these is transmission system adequacy. Transmission system adequacy is a concept which is applied to EirGrid, the national transmission system operator, and it must evaluate any new project in terms of whether it meets the requirements of security of supply. In considering these technologies, their characteristics must be compared in this respect.

I should explain the related graph. On the x-axis, one can see the probability that a certain technology fails; in effect, how likely it will be to have a failure on a line. On the y-axis we see the average time required for repairs. Thus, the unavailability is represented by the area covered by these two parameters. In the red ellipse, which is hardly visible, we can see the characteristics of overhead lines. As a matter of fact, overhead lines are exposed much more to weather and various environmental conditions than underground cables. For this reason, they are out of operation quite frequently. However, in most cases, it takes only seconds or minutes to put them back in operation because the fault is cleared automatically. This is different for underground cables. If there is a failure in an underground cable, it always needs to be repaired as there will be damage. For that reason, the amount of time required to put underground cables back in operation is much greater.

It can be seen that the shapes representing unavailability for underground cables are at least an order of magnitude - that is, a factor of ten - greater than those for overhead lines. In addition, the shape and area of the underground cables differs considerably from those of overhead lines. This is due to the fact that there is quite limited experience with extra-high-voltage underground cables. This technology has existed commercially for around ten years, or 15 for some projects, and it is difficult to obtain reliable statistics, which results in different estimates of reliability. Still, the difference between the two technologies is very high. Thus, we came to the conclusion that it may be a challenge for EirGrid to prove that underground cables used over extended distances, as discussed here, meet its reliability criteria in terms of transmission adequacy.

When we analysed the policy implications of both technologies, we found that there was no significant difference. This means there is no policy, either national or European, which will hamper the application of either of these technologies. There is one slight issue - this is related to what I was just saying - which is that if security of supply is adversely affected by the choice of technology, this will have policy implications.

There is also the issue of cost, which naturally has been the subject of much discussion. We compared a number of underground cable arrangements and found that one particular arrangement is the most cost-effective in comparison with overhead lines. We compared the investment cost per kilometre of an overhead line circuit with that of an underground cable circuit of the same capacity, which is quite important. As the capacity of underground cables is limited by the thermal conditions of the soil, one overhead line circuit is equivalent to two underground cable circuits. If we want the lines to carry this capacity we cannot do it with less. The operational costs consist mostly of losses and are calculated on a life-cycle basis. These were compared for line loadings which are typical of the transmission system in Ireland. We end up with a five-fold difference in investment costs. In terms of investments, the ratio is a factor of five when the cost of underground cables is compared to the cost of overhead lines and a factor of three when compared on a life cycle basis. These numbers are related to abstract case studies and may be affected by many other parameters but we see them as a reasonable estimate for guiding discussion on the issue.

Committee members have heard that any infrastructure technology has negative impacts. Careful mitigation of these impacts is important and perhaps at least as important as the choice of technology. Members will understand current state-of-the-art extra high voltage underground cabling, as discussed, does not yet compare adequately to overhead lines and may be inappropriate to meet EirGrid's transmission requirements. The limited track record and statistically unexamined experience of underground cables makes this difference even more relevant in decision making.

Members have learned that underground cables are associated with substantially higher costs. However, this and other disadvantages must be seen in context of the adequacy of the transmission system. Whereas later aspects are qualitative, the first may be substantive.

In brief, this presentation is intended to give a sense of our report. We are now happy to answer questions.

Deputy Simon Coveney

I welcome the delegates. This is a sensitive political issue, as well as a challenge from an electricity infrastructure point of view. Mr. Burges is correct in saying Ireland needs an electricity supply which requires infrastructure. We are trying to analyse the report and take from it the appropriate research that can help in decision making from a policy point of view. In that context, I have some comments to make and questions to ask.

The report was accompanied on release by a letter from the consultants to the Minister for Communications, Energy and Natural Resources, Deputy Ryan, and his Department. The letter was published with the Minister's press release. Having read the report and the letter, it seems that in the letter there is an emphasis on barriers, on the reasons the underground option is not deemed appropriate in terms of the infrastructure proposed. There is not an adequate mention of some of the positive developments in respect of underground infrastructure in other parts of Europe and eslewhere in the world. In particular, the executive summary states underground cabling, at transmission levels of 400 kVs, is a young technology showing dynamic growth.

There is a very balanced reflection in the report of the problems as well as the potential opportunities that exist. Some of those opportunities are being taken up in Germany at policy level. The letter to the Minister seems to have impacted directly on the press release related to his response to the document. It is extremely negative. That has been taken up in the media, which is unfortunate because there are some positives in this.

I want to put some of my comments into context. There is a problem here. We are assessing the available technology on the basis of what has been done to date, and this does not necessarily reflect the fact that technology is improving year on year in terms of the capacity to deliver high voltage electricity infrastructure underground. Had that view been taken ten or 15 years ago, one would not have seen electricity cabling going underground, even in an urban setting. At some stage somebody has to take a leap of faith and put in place the available technology in a rural setting. That is now starting to happen in Germany.

I want to focus on some specific issues because the delegation can be helpful in answering some of the questions. I want to focus on the costs and the cost analysis. The diagram on page 86, chapter five in the report, which discusses a cost analysis of underground versus overground, states, "For a single circuit OHL as being the standard design choice of EirGrid for 400 kV transmission, a value of €700,000 per km has been assumed". From where does that assumption and figure come? It is the basis for everything else in the report but I do not know from where it comes. Maybe I have missed that in the appendix at the end.

In relation to the graph shown on that page, there is an investment cost along the left-hand vertical line, which I understand. The other baseline is 1,000, 2,000, 3,000, 4,000 and so on. Will the delegation explain what the transmission capacity represents? The transmission capacity for a 400kV overhead line is in the same region as a lower voltage, presumably a 220 voltage underground capacity line which is directly above it. If one examines the cost comparison between the two, they are certainly not five times one or the other, they are more like two or three times. A little more explanation on the cost graphs shown would be helpful for non-technical experts in the electricity field.

When one reads the chapter on what is happening regarding capital costs in Germany, there are strong comparisons to what is happening in Ireland. They are trying to facilitate more renewable energy from wind and other sources which will be placed in different parts of Germany, and as a result they have to build a backbone grid infrastructure to facilitate that. We are trying to do the same in Ireland, which is a major challenge for EirGrid. In Germany there is an active policy debate on the underground versus overground options, which is also what we are having. There have been a number of techno-economic viability studies. The two quoted here show a cost differential between the underground and overground options. The figure in respect of the underground route varies between 1.6 and 2.1 times the cost of going overground, whereas in Ireland it is estimated that going underground would be approximately five times the cost of going overground. What is the difference between Ireland and Germany? Is it the topography? What is the difference between the case studies taken here and the routes measured in Germany, which I would deem potentially more accurate because Germany was dealing with live routes as opposed to fictional case studies as happened here? It would be helpful if Dr. Burges could provide some detail on that.

I have a question on capital costs but I will return to that later because any comment I make will depend on the answer Dr. Karsten gives. In terms of the operation and maintenance costs, is it correct that under the operational conditions typical of the Irish transmission system the resulting cost differences between both options are likely to be insignificant so that there is not really an issue in terms of operational costs?

That brings me to what I believe is the key aspect of this study, namely, reliability and forced outages, a major concern. In terms of the capital costs, one of the things not being factored in is the timeframe for putting this infrastructure in place overground, given the level of community and political resistance, legal challenges and so on, which will extend the timeframe considerably compared to the potential timeframe for putting the infrastructure underground. The longer the project takes to complete the higher the expense. The cost of putting in place infrastructure of the type proposed in Meath, Cavan and Monaghan might turn out to be nearly as much as putting it underground by the time all the legal challenges are exhausted. I accept that without those constraints the cost of putting infrastructure overground is significantly less than putting it underground. However, that is not the whole picture. The level of community resistance in those areas is extremely strong.

On the reliability issues, I was a little confused by the press release and the letter to the Minister in which it was stated that the expected forced outage rate is ten times higher for underground systems than for overground systems. Dr. Burges explained that; in the report it is stated that it is a factor of 1:2. However a factor of 1:2 means ten or 20 times higher. Is that correct?

Dr. Karsten Burges

It is one or two orders of magnitude, which means one or more zeros after the digit.

Deputy Simon Coveney

That is fine. I want to establish whether Dr. Burges's estimates of reliability and the likelihood of outages and the time it takes to repair them are based on underground cabling in an urban setting where there is a much higher likelihood of interference and outages or are they based on underground cabling in a rural setting, in a field. There is a false assumption that we are comparing like with like. We are comparing underground cables in an urban setting, in terms of reliability, with overground cables in a rural setting. Is it not the case that the forced outages or reliability concerns in a rural setting are not the same as reliability concerns in an urban setting where there are so many other factors that can potentially affect the reliability of those lines? Is that a fair assumption? I accept it is difficult for Dr. Burges to assess reliability concerns with underground cable in a rural setting versus overground cable in a rural setting because underground cable largely does not exist in a rural setting and it is difficult to make those comparisons. However, if we are making the assumption in this report, which is a recommendation to the Minister, that we should not be putting underground cable in a rural setting and we are using as a basis for that assumption reliability of underground cables in an urban setting, that is a genuine concern. I would like Dr. Burges to comment on that.

It also potentially explains the reason for what they are now doing in Germany, which is trying to assess the comparison between underground cables in a rural setting versus overground lines in a rural setting. Germany is passing legislation to force that to happen, particularly in environmentally sensitive areas such as coastal areas where lower voltage overground lines cannot be laid within 20 kilometres of the coastline. That is a series of questions on reliability on which I would appreciate an answer.

Regarding the policy direction in Germany, laws have now been passed at a federal state level as well as a regional level which requires the infrastructure provider and operator to put entire lines or a percentage of lines underground as a result of political pressure. Does Dr. Burges believe that type of planning is appropriate in Ireland in the context of what we must achieve in the next ten to 20 years regarding the demands on the Irish grid if we are to facilitate the type of dramatic increase in reliance on wind and wave energy and the other sustainable renewable resources we are looking to develop?

Chairman

If Dr. Burges's colleagues want to contribute to the debate, they are more than welcome to do so.

Dr. Karsten Burges

Most of the questions relate to our contribution to the report. To ensure that everybody can follow my explanation I would like to share these graphs with everybody. I do not know whether the members have a copy; more will be distributed.

What members will see is the graph referred to on investment costs. There were two questions before that but to clarify the position on where we took the assumption of €700 per metre overhead line, which is the reference for the whole comparison, on the right of the text members will see another one, overhead line 2 systems, which is reference to a report from Professor Oswald, a reputed expert on cables and transmission technology in Germany, and the €900 to €2,000 per metre refers to pylons in constructions which are common in continental Europe, with two systems on one tower. In Ireland, there is one system. There are 400 kV lines with one circuit on these towers, which means three wires forming one system. The €700 per metre is, in that way, close to that external reference we also have. In addition, this techno-economic assessment involved significant contribution by Professor Brakelmann, who is an expert and who has close contacts with the industry. From that position, I feel confident with that number.

Deputy Simon Coveney

Does the reference relate to the cost that EirGrid has had to endure on previous projects or is it based on international best practice?

Dr. Karsten Burges

It is based on international best practice, as are all these technology assessments. On the issue Deputy Coveney mentioned, all these costs of planning and of these legal steps one must take to make such a line a reality are not covered here. It is just the technical cost of buying the equipment and implementing it in the landscape so that it is running.

Of course one may consider all kinds of external costs in order to make a more comprehensive balance between technologies. However, then one encounters the problem that including one external factor always raises the question of which other should one also include. The delay which is translated into monetary values will be offset, for example, by the possible devaluation of property and an increase of loss of load, both of which factors have an impact on the national economy. They were outside the scope of this report but even if we included them, I doubt whether they would contribute to informing policy makers because those figures are very difficult to estimate. That is why the graph clearly relates to technology costs, not external costs. Does that answer the question?

Deputy Simon Coveney

Yes.

Dr. Karsten Burges

Deputy Coveney referred to the operational costs and the differences in certain studies. There were quite a number of comparative studies on underground cabling and overhead lines in the international scene in the past five to seven years and the most obvious conclusion one can draw is that the outcomes vary considerably. There is no single figure for the cost ratio between underground cable and overhead lines which one can derive from those studies. The reason for that is the dramatically improving technology on underground cabling and the experience which has been gained, but also the extremely high impact of local conditions. We had to take into account in the evaluation, for example, that the transmission assets in continental Europe are loaded much higher than are those in Ireland. Here EirGrid expects an annual average loading of new lines of 20% of their nominal capacity, which sounds quite low. In Europe, these numbers are much higher but there are reasons for this. First, the European transmission system is a highly-meshed multi-node system, with many transits or flows from A to B, which automatically results in higher loading of those lines. For that reason, consultants carrying out other studies must take those higher loadings into account in their calculations. Overhead lines give rise to higher losses at higher loadings. That is not the case when they are lightly loaded. Evidence of this is provided in our conclusions.

In the case studies section of our report - figure 9-3 on page 180 - we also calculated the losses in respect of several scenarios relating to line loading. In my presentation, I only referred to that which is most likely to be representative of the Irish context. However, we also calculated it with higher loadings. In such circumstances, losses relating to overhead lines increase where higher loadings are involved.

Deputy Coveney also referred to the issue of reliability.

Deputy Simon Coveney

In the German studies, does the overall cost of 1.6:1 to 2.1:1 refer also to the capital cost?

Dr. Karsten Burges

Yes, but also in that case it depends on the consultant. The slide relating to the reliability issue shows that there is a significant difference. This highlights that there is no consensus on the figures. The findings of factors of the order of 1.2 to 2.1 are challenged and are not just accepted. We are convinced that what we delivered in our report is a reasonable figure.

The Deputy is correct that the technology relating to underground cables develops extremely quickly. Ten years ago we did not have 400 kV underground cables on a commercial scale such as those which are now in existence. If that had not been the case, the entire study would have been obsolete. For our report, we considered what is currently state of the art technology. Over a five-year period, the figures will be different. Ours was a desk study. We did not carry out research in respect of components, etc., we merely referred to the expertise that is available in the international arena and identified what exists at present. We are communicating the information we uncovered in order that a decision might be made.

I cannot forecast the developments that will take place during the next five years. All I can say is that the plans that are being discussed at present must be implemented in the near future. The committee must follow developments carefully. We suggest in our conclusions that experience should be gained and that part of this technology should be put in place in Ireland in order that people here might learn what is involved with its operation and maintenance. We state, however, that it is not adequate to form the backbone to the transmission system.

I have in my possession another slide - I will circulate it to members - which provides information on 400 kV lines that have been put in place elsewhere. The Deputy referred to the experience of other countries in this regard. The existing experience is not the backbone in the transmission system. This slide shows the longest existing 400 kV line, which is a 40 km section of TAPCO the Tokyo transmission system. I must mention two things about this. There is a very light arrow on the right to a grey line and this is a branch from the transmission system into the inner city. This is different from having a path in a mesh network that transports electricity throughout the whole system.

The Deputy emphasised the difference that may exist between rural and urban systems in terms of reliability and statistics. I am convinced the figures we provide are representative for 400 kV AC underground cabling generally and am confident in saying that. Having a 400 kV underground cable in an urban area is different from what we are used to now with underground cables in urban areas. What we have are just distribution systems that are buried under the road or adjacent to it. Therefore, they are vulnerable if construction work is being carried out. One would not bury a transmission system in the road like that. We would protect it. From that perspective, the likelihood of it being hit during construction work will be much less than the current experience with current distribution systems. This is such an important infrastructure it will be protected. From that perspective, I am convinced the difference between urban and rural sections in terms of reliability will be negligible. It will be the same as with a gas pipeline in a city. Nobody will be able to hit it with a drill.

With regard to the German context, the Deputy is right. Legislation is being put in place currently. At national level, Germany decided to have underground cabling in coastal areas, cabling that is not generally extra high voltage, mostly 110 kV and 150 kV, which was mature technology and just added costs that had to be accepted by the regulator.

I apologise for the inconvenience but I need to distribute another document. There are some sections in the German meshed transmission system where at state level the decision has been taken that certain sections and parts of these lines will be put underground. These sections, which are required to be built, have been identified in the framework of the Dana study, which was quite an extensive study on the impacts of the renewable targets on the transmission system in Germany.

It is important to realise that these assets are used to transport the electricity which is generated mostly in the north of the country to the load centres in the south. Even if we lost such a connection, this would not threaten supplies in the south, because there are conventional power plants there. It would affect the transport of renewable electricity from the north to the south, which is of course a cost issue, but not automatically a reliability issue. From that perspective, the projects being discussed here are different. This North-South interconnnector which is currently under discussion is not being planned for renewable energy, even before these developments which have been drawn up in the all-island grid study and in other documents become a reality.

Ecofys was involved in the all-island grid study. The key conclusion of that study was the impact on the transmission system is quite limited. These renewable targets will require a massive extension of the networks in Ireland but mostly at lower voltage levels. This is the difference between the results in the Danish study and in the German developments.

I refer to cases where strong public pressure resulted in the use of underground cabling. This happened in other countries besides Lower Saxony where legislation has been put in force. There is a connector between south-eastern Germany, which is the control area of Vattenfal transmission, and Bavaria which is the control area of E.ON NETZ. They had to cross the Thuringer Wald which is a very popular area with a long-distance nature trail which is visited by millions of people every year. There was much public resistance. In response to this pressure the transmission system operator who was responsible for planning the line decided to use a lower tower and in parallel with overhead lines. They had planned to have a second system which would be a tower with two circuits, six wires. They instead opted for one lower tower with three wires and put in another system of underground cabling in order to gain experience. It was for a limited distance and if it were to be lost, they would still have the other system in place. This is what we recommended in our conclusions, that experience should be gained but one should not completely rely on the technology at this stage of development.

Deputy Liz McManus

I will be brief because I am conscious there are many people here who have a direct connection with this project who wish to ask questions. I appreciate that Dr. Burges has presented us with a technical report which is very professional. We are presented with a political problem to which there is no easy solution. One concern that seems to be at the back of all this from the point of view of the providers, is that a decision to go underground in this particular project would set a precedent which would be very expensive and every job from then on would require to be underground. I ask Dr. Burges to comment on this point because it seems that whether or not this is an interconnector, it is being called an interconnector. It seems to be a unique project which should be regarded as such.

Dr. Burges in his report states that either option is acceptable but that there is an issue of security or of reliability. Dr. Burges has already answered Deputy Coveney's question on this point but it is very difficult for a non-technical person to see how putting a piece of infrastructure underground which is very well protected somehow leaves it more vulnerable than putting it overground. I ask Dr. Burges to clarify this point.

I have no reason to argue with Dr. Burges about the costs as it is obvious he has made a comprehensive study of this. However, he stated the three times figure to which he referred was very dependent on parameters. I note EirGrid stated at a local health meeting in Monaghan that it was carrying out a specific study as regards the terrain and the possibility for underground cabling. Am I right in thinking that unless that type of study is done, we are very much in the abstract theoretical area? If the particular conditions are not assessed, it is quite difficult to apply the principles Dr. Burges has outlined so well. How important is a study of this type in terms of finding a solution?

The other question I want to ask relates to magnetic fields. As I understand it, Dr. Burges is saying that undergrounding means the magnetic field is much more concentrated on the particular corridor. Is that not an advantage? Presumably there will have to be proper acquisition along the corridor, whichever method is used. I thought that would be a plus in terms of ensuring a widespread area is not affected by the magnetic field which, understandably, is of major concern to people.

Dr. Karsten Burges

I thank the Deputy for her questions. I completely agree, although I do not believe this was within the scope of our study. I agree, however, that if a precedent is created, it will be there for decades. With every transmission project there will be a discussion as to whether it should be put underground. We did this and have shown how it works.

There is one very important factor to be considered in that context. Also, internationally there are examples of extra high voltage underground transmission. There is no network in the world which consists only or in large portion of underground cables. As the Danish study released in April this year has already clarified, much research is required before we can say that such a system can be operated with the knowledge we have at present. It will mean there will be another political challenge to explain to people, in effect, that while it was done in such a way once, that does not mean it can be repeated.

Having said that, this should not be a reason for not gaining the experience. One should be prepared and active as regards learning what underground cables mean for the transmission system, while not suggesting that there is a new option for transforming the Irish system to a completely different structure. The reason underground cables are more vulnerable is not because they are exposed to more risks or impact from the outer world. It is a very challenging technology, 400 kV over such a distance, of some 20 cm. It is something that fails once in a while, and that is the basis for these statistics. It is not that impacts occur from the outer world but rather from internal faults which, in some cases may be down to manufacturing or other reasons. We even do not know why something fails. It happens with all technical systems once in a while and the statistics at present show that they are less reliable than overhead lines from this perspective.

Regarding the costs, I agree that if one wants to arrive at a figure, then a complete study is needed. Our case studies had several very important assumptions, which may be speculative for a concrete project. The first and most important one is that we assumed the length of the circuit would be the same going from A to B, which may be wrong. One may be obliged to surround dwellings for an overhead line, while for an underground cable, there may be soil conditions in which one simply cannot put in the cable. This means there may be a huge differential between both cases if one considered a concrete project.

Another point is that at present, given the limited market volume, it is difficult to get hard figures from the industry in respect of some of the cost components. As for the cable we took into account in our assessment, I compared the cheapest underground cable option with an overhead line. However, this cable, a 3,000 sq. millimetre aluminium conductor, is not something that has been implemented anywhere in the world. While the manufacturer has stated it can deliver, there are no list prices for that technology and it is simply a case of communication between the experts. There are uncertainties and from that perspective, I agree that one really only knows the real figures when one has a concrete case study with concrete offerings from industry. Until then, I am quite relaxed with a factor of two in those results, when compared to other studies.

As for the last point on electromagnetic fields, the Deputy is correct. They are more concentrated in the case of underground cables, which is perceived to be a plus. It may be advantageous when one considers urban areas. The graph of the magnetic field demonstrated that if one is 20 m or 30 m out of the axis of the line, in both cases the magnetic fields are much lower than the international standards. In addition, one must take into account that such lines are designed to meet such international standards, which are defined for permanent exposure. This is unlikely, at least for an overhead line, as one does not remain beneath it. Moreover, such lines are only partially loaded most of the time. As I noted, EirGrid's average load is 20% of the nominal capacity. In practice, this means that in both cases, this is not an advantage pertaining to overhead lines, the magnetic fields, which are measurable or to which individuals are exposed, are significantly lower than the international standard limits.

Deputy Johnny Brady

I welcome the consultants and congratulate Deputy Nolan on his appointment as Chairman of the joint committee. I wish him the best of luck in the future. Although I am not a member of the joint committee, I suggest that, rather than taking questions one at a time, he should allow a few members to ask questions before seeking a response from Dr. Burges, because some of the questions I wished to raise have been asked already. It would be fair to other members to so do.

Chairman

I will take Deputy Brady up on that offer. We will take questions from two members after Deputy Brady.

Deputy Johnny Brady

Dr. Burges admits he has relied on assumptions for the placing underground of the cables, as the industry still is in its infancy. Therefore, the cost could be lower than the higher rate he has suggested, particularly as new technology in the field of XLPE cables is advancing. Can one accept this assumed cost estimate as being reliable or realistic? Deputy Coveney already has asked whether the consultants have taken into consideration the delay arising from court cases and so forth that lie ahead of EirGrid in the future.

The WHO guidelines on exposure limits to electromagnetic fields produced by overhead lines have been examined by various bodies from a number of countries. Several have reduced their exposure limits to a lower level than recommended by the WHO. As suggested by most recent studies, this is primarily due to growing concern over health factors. Should this matter be considered when choosing whether to install the lines overhead as opposed to underground where exposure limits are reduced? I welcome that the consultants agree that health issues comprise a considerable public concern and cannot be disregarded.

Deputy McManus referred to the major barrier to placing cables underground. In future, it appears that all cables will need to be underground. Placing cables underground can be expected to have forced outage rates at least ten times greater than those of overhead lines. On what is this figure based? Is it on outages on long-cable connections such as interconnectors or on shorter urban lines, in respect of which one can expect greater interference from civil works? For example, what are the outages on the Murraylink? It adds 220 MW to the south Australian system, enough to meet the electricity needs of approximately 120,000 households, stabilises the network during normal operations and reduces the risk of faults. Due to its robust technology, HVDC light systems cannot be overloaded and are not exposed to the risk of cascade tripping. Mr. Peter Smits, head of ABB's power technologies division, stated:

Grid stability and security are higher on the agenda after recent electricity blackouts. With HVDC, ABB is providing grid operators with solutions to a widely recognised challenge.

Ecofys's report refers to frequency of outages being one or two orders of magnitude. How did this figure become ten times greater? Two case studies were cited to suggest that costs would be up to five times higher. Why did Ecofys not cite two outage case studies using comparable overhead and underground interconnectors? According to the report, underground cables are severely limited in terms of transmission adequacy and are not equivalent to overhead lines as regards security of electricity supply. If so, why has an underground interconnector between Norway and Sweden been proposed?

Deputy Shane McEntee

I welcome the witnesses. This is the committee's second or third presentation on the matter of underground and overground cables.

I would like to have a few specific questions answered. Given that our constituents have made it clear that overground cabling has a significant effect on their properties and areas, why are we not placing cables underground? At an initial public consultation, Deputy English and I were informed that the cost was eight to ten times less. In May, another company, Oceanteam, made a presentation in which it claimed it could do the same job with the same output for the same cost. At today's presentation, however, we have been told the costs will be five times higher. According to Ecofys's report, the ratio in Germany is between 1.6:1 and 1.9:1. We are getting somewhere, which is the answer that people want.

No one wants to stop the project. Given the price of oil, it must occur quickly. As Deputy Johnny Brady stated, we do not want the matter to go before the courts. Have the witnesses been limited in their report, namely, is their submission to the committee not a full and proper study to allay the fears of people in counties Meath, Monaghan and Cavan? Have they been unable to do a report on a specific route? Is the study good enough to allay fears concerning underground versus overground? Which is the best way to proceed?

Deputy Margaret Conlon

I welcome the visitors. Although I am not a member of the committee I have a keen interest in the issue because I attended many meetings in Cavan-Monaghan. It is of major concern to my constituents. I am not a technical person and do not understand much of electromagnetic fields, AC and DC. From the outset EirGrid told us that this was not technically feasible. In the opinion of the delegation, is it technically feasible? Irrespective of cost to start with, can it be done? Did the delegation examine an alternative route, such as along the coast, without coming through Cavan-Monaghan but doing the same thing?

I agree with what Deputy McEntee said. The fears and concerns of the public have not been allayed. On all sides of the House we agree that the interconnector is necessary. I agree with the delegation in its comment on page 136, that "public opposition will increase the required construction time for OHL and the target timeframe of 2011 can not be reached". Given what the delegation says about experiences in Germany and Austria, when can this project be completed? The delegation has not given serious consideration to public opposition, the level of protest and the length of delay that could result from going overhead.

The impact on communities is identified as the most significant issue. Where I come from, we have a lovely Drumlin landscape, unspoilt, and while we do not have the weather for tourism, we get our share of tourists. This would be a blight on the landscape and disfigure it. The report considers only direct costs but there are many indirect costs. For example, there is the potential fall-off in tourism earnings. I respectfully suggest this report does not evaluate the proper cost because the delegation has not taken direct and indirect costs into consideration. One cannot be considered without the other. Is a separate report not needed to deal with this aspect?

Page 9 of the report mentions that "legislation on a global scale is generally becoming more stringent and complex". Is the delegation indicating that the EU is considering banning or severely restricting the overgrounding of high-power lines? The delegation referred to how technology is evolving and changing. Who knows what people will come up with five years from now? If one looks at the way transport has changed over the past number of years, one can now sit in a car in Donegal, type the furthest point in Kerry into a satellite navigation system and one will be brought directly to the door. It is difficult to believe that when we have that technology, it would not be quick to find outages and breakages using this technology and repair them quickly.

The delegation referred to situations where there is no physical space for the lines overground and they must be put underground. Where there is no choice, cost does not come into it. Is Mr. Burges saying that in the cities where the lines are underground, the electricity transmission is less reliable, with more outages and so forth? Does he have evidence to back up that claim?

Mr. Burges referred to the experience of underground cabling in other countries. Does he have the hard evidence to show that it is less reliable? I find it difficult to accept the fact that if lines are put underground, there will be such a high level of outages and the system will be so much less reliable. We have gas pipelines underground and we do not suffer from enormous problems in that regard.

If one is forced to place cables underground, what is the estimate of how much, in kilometres, can effectively be placed underground to provide a safe and reliable supply?

Dr. Karsten Burges

Thank you for your questions. I will start by addressing the reliability issue. The figures we gave were per kilometre figures. That means that the distance does not make a difference. We compared one kilometre of overhead line with one kilometre of underground cable. If one has ten kilometres of line or cable, the values will simply be multiplied by ten.

The likelihood that an underground cable will fail is lower than with the overhead line. Indeed, with the newer technologies, the likelihood is significantly lower. However, the point is, if one does have a failure, one must repair it. If lightening strikes and damages the cable, one must dig up the area, remove the damaged section of cable, replace it with a new section and then put the cable back underground. That is the difference. It is not something that can be done within a few hours. In fact, it would be challenging to complete such work within a number of days. This difference makes the final difference in the forced outage rate. It is not just the likelihood that something could go wrong but also the total time involved in getting the system back into operation.

In response to the direct "Yes" or "No" question, it is a viable technology which is being sold commercially. However, if one wanted to achieve the same level of adequacy in the transmission system, one would not have to install just two circuits, but six or seven. That would mean an increase in cost by anything from a factor of three to a factor of 15. One may generalise and say that all technical challenges are, in the end, economic challenges.

The Deputy stated that we did not evaluate the monetary value of a delay or of losses in property value. Such issues were not specified within the scope of this study. Such evaluations, in any case, would not contribute to the political decision which has to be made because the uncertainties in those external factors are enormous. One could end up with ten consultant reports and 11 findings, which would not support the political process which is required here.

Reference was made to the Australian experience. I am aware that Oceanteam, represented by Imera, has appeared before the committee to outline its capabilities. It estimated the cost of a 60 km connection at between €250 million and €280 million which, according to the findings of our study, is approximately five times the cost of an overhead line. This huge difference arises because of the technology used in Oceanteam's converter stations to utilise direct current for transmission. A similar technology is used in Australia.

Direct current has significant technical advantages in that it uses only two wires, thereby offering a reduced cross-section and smaller magnetic fields. However, additional costs are incurred in constructing the converter stations needed to convert the alternating current used in our transmission systems to direct current. Oceanteam indicated that approximately €100 million would be required for such a converter station, which aligns with the findings of our report. The reason is that the technology was originally developed for offshore transmission, which rules out the use of overhead lines. The connection simply has to be put into the water and, therefore, housed in a cable. For technical reasons, the distance over which an alternating current can be transmitted is limited, so direct current and converter stations have to be used over longer distances or in marine interconnectors. The same does not apply in respect of onshore transmission, which only requires the use of direct current over long distance interconnections.

The investment required for these technologies is of an order of magnitude higher than what we have to assume in respect of overhead lines. The other disadvantage is that current conversion is associated with losses which, on a lifecycle basis, have a significant monetary value and implications for the transmission technology's carbon footprint. I am convinced that if ABB was invited to state its position on this technology, it would confirm the figures we derived in our report. I do not want to say it is not a viable option but it should be applied in areas where it adds value, such as connecting parts of the transmission system over long distances. The control capabilities of converters are needed to support systems with technical limitations, which is not the case in Ireland. I will leave the question of whether we considered alternative routes to my colleague, Mr. Conor Wall.

Mr. Conor Wall

Dr. Burges refers to Deputy Johnny Brady's question. The report was not site or route-specific but a comparative assessment of the merits of one technology vis-à-vis another. It is up to the decision maker to look at a particular route and use the report prepared by ECOFYS and ourselves to make informed decisions as to whether one technology had greater merit over another. Given the project-specific components, each project will vary depending on topography and many other issues.

There were two other questions from Deputy Brady. One questioned whether our study was limited and whether it could be used to allay fears. We were asked to prepare an information tool for future transmission networks but An Bord Pleanála is the decision maker for significant infrastructure development. We were not limited in scope but were allowed to look at different aspects of the case, such as the technical, environmental and social aspects of both technologies. As for whether the report will be enough to allay fears, that is not really part of our brief. However, it should provide enough information to enable the decision maker to take a good look at both technologies.

The report highlights the likelihood that overhead transmission lines could impact property valuations. However, on page 131, figure 6.1, it shows that 50 other types of impact were possible. Those impacts were not identified by either Golder Associates or ECOFYS but by stakeholder engagement. The submissions from the public showed most concern over the effects on communities of electromagnetic waves from overhead transmission lines but there are potential impacts from undergrounding, such as on land use and ecology. Each case is project-specific and the document we have produced can assist in the decision but the answers are not all in the report as they will depend on the project in question.

Deputy Seymour Crawford

I congratulate Deputy Nolan on his election to the chairmanship of the committee. I welcome the fact that a number of people with an interest in the proceedings of the committee have attended. A number of councillors are present from Cavan and Monaghan, among many others with a keen interest in the issue. They are genuinely worried about what the future holds. Much has been spoken of communities but, for me, the most important issue is how this affects communities.

In reading the Minister's statement after the report was published I am compelled to ask who read the report for him and how he could have come to his conclusions. In fairness, the report is reasonably balanced and gives some indication that it is possible to put this infrastructure underground as opposed to overground.

I will comment on one issue arising from the Minister's statement, which is that exposure to magnetic fields may be higher directly above an underground cable than under overhead lines, and additional measures can reduce the magnetic field for both options. What does the Minister mean by this and what measures would be necessary to bring about an acceptable situation? This area is very technical and I am not technically minded. There are people who have studied this, have taken a very keen interest and are worried about the effects this might have on the future health of their families.

On the same community issue, there is the matter of valuations and damage to properties, tourism, etc., which has not been taken into account to the extent that is required. It will have a major effect on the willingness of people to co-operate or otherwise in the laying of this infrastructure in future.

We should get one thing absolutely clear - this is not an interconnector, as we were led to believe at the start. If it was an interconnector, it would simply be put down under the sea. This is the backbone of a system that the ESB and EirGrid want to put in place for the future, and it is vital we understand that.

On the matter of being hesitant to go underground, the delegates stated in their summary that underground cabling is a young technology showing dynamic growth. The bottom line is that if Henry Ford did not make his car, in what way would the automobile industry have developed? There is clearly a dynamic towards underground technology and we must look at every possibility.

I do not want to go back to the German issue, although it is clearly very interesting. They have done things in the past which we have not, such as using meat and bone meal for power production. We were not prepared to do so here. The Germans are insisting these cables go underground. This is a political issue and there is no point in ignoring it. Germany is partly led by the Green Party in that country, which is of some interest to me.

The delegation stated in its summary that there is limited experience with regard to reliability statistics. As a person coming from a farming background, I built a home and farmyard some 35 years ago and was stupid enough to put in overhead cabling linking the electricity between home and farmyard. Many times, for all sorts of unbelievable reasons, the structure was damaged. Approximately 27 years ago, I put the cable underground, and thank God, from that day to this, we never had another problem with it.

I find it very difficult to understand how, if a cable is put underground properly, it cannot be more reliable than an overground arrangement. It was mentioned that a lightning strike could damage the underground cable and it would take a long time to rectify the problem. I wonder if we are looking at similar weather patterns in this country as compared to what might occur in Florida or somewhere else. We must consider these issues.

The matter of site evaluation studies has already been mentioned but it cannot be over-emphasised. We are dealing with information regarding underground cabling most of which, I understand, is based on experience in urban areas. The cost factor compared to cabling through rural areas, as has been proposed for counties Meath, Cavan and Monaghan, must be completely different. We have seen other studies in which machines have simply pulled the cables underground after the ground has been sufficiently levelled out. Gas lines have been put through with no problem. It is hard to understand this.

Dr. Burges mentioned existing policies. That is a political matter. The executive summary states that underground cabling is complex and affects a variety of stakeholders. The costs of this technology, in particular external costs, devaluation of property, employment effects, and the possible costs of loss load in case of transmission system failure, are hard to quantify. If there is an insistence that the lines be placed overhead, the process will be complex and argumentative and may end up in the courts, but if it is agreed that the lines should be placed underground the project will be carried out in an amicable and friendly fashion. Has ECOFYS quantified the time losses that would result from the former course of action?

I was interested to hear the comparative costs. I pay tribute to the efforts made by EirGrid in more recent times to meet and talk to representatives from the area. When I met the chief executive of EirGrid not so long ago in this building, he said that to the best of his knowledge the cost ratio of overground versus underground was 9:1. However, it was stated in the presentation today that the cost ratio is 5:1. In the general experience it is in the region of 1.6:1. The biggest failure of the report is the lack of accurate evaluation of what would happen in a rural rather than an urban setting, on which most of the previous reports were based. Some of the information in the slides has come from EirGrid itself, which is interesting.

I have a number of questions but I do not want to delay the meeting. In view of the fact that the study is confined to a desktop analysis of the available technologies, with no site visits to the potential routes announced by EirGrid, can Dr. Burges summarise what he sees as the limitations of the study? What impact, if any, would these have on its conclusions? The fact that it was a desktop study has serious implications.

There are still major questions in the area of health. Could Dr. Burges tell us whether advice was sought from those in the medical field? At a recent meeting in Corduff we heard that out of 107 papers on the question of health issues associated with overhead lines, 69 concluded that there were health risks. That is a large number of reports. I do not know if these have been fully evaluated but that is the kind of information being obtained by the groups concerned.

It is clear that the possibility of placing such cables underground is the subject of serious consideration internationally. This has not happened by accident. People are genuinely worried. The German situation is a precedent and I understand other countries have already acted accordingly.

The case was put to us that only a very small percentage of cabling has ever been put underground. It would be a pioneering step for Ireland to show leadership in that regard. It would demonstrate that we had taken account of the anxieties of the general public. In the end the cost factor will not be that significant if everything is taken into consideration. It is all very well to take cables and manpower into account but we must also consider the rights of communities and the cost to them in respect of tourism, property and all the other factors, especially possible dangers to health.

Deputy Thomas Byrne

I will not delay the committee because I know that we will return to this issue and possibly, ultimately, to An Bord Pleanála if the project goes ahead. I welcome the report which seems very impressive. If I had time I would love to read some of the material referenced in it. Much of it is in German but I would look through some of it if it were available as required in the Oireachtas Library.

Many of the questions I had have been answered. Comments were made, with which I did not agree, questioning the independence of the authors of this study. Perhaps those comments might be addressed as I believe it is important that they be answered. I realise this is a complicated project. Is it possible for the industry to publish a request for tender, stating that EirGrid requires a transmission system and interested companies that supply either type of technology may apply? Is it technically possible for companies to tender for the system under discussion, showing what the costs are, including some of the operational costs? Perhaps this has not happened before because EirGrid would simply build the system. If a council is constructing a road, however, it puts the project out to tender and invites prices for the job. There appears to be some doubt about the cost of this project because some of the technical companies do not seem willing to state what the cost is. Perhaps there is not enough relevant experience for them to do so.

The delegates stated that it is technically feasible to put an underground cable in place, despite limitations as outlined in the report. EirGrid stated that it is not possible to use within the transmission network the DC line that runs under the sea. Do the delegates agree?

Senator Joe O’Reilly

My constituency colleague, Senator Wilson, has a personal appointment and hopes to return in time for some of the meeting. He asked me to extend his apologies in the event that he cannot do so.

I also welcome four public representatives and colleagues to the public gallery, Councillors McKiernan, Bannigan, Keenan, and McElvanny. I commend them on their significant voluntary commitment over many months to the exploration of this issue, as I do all the voluntary personnel in the gallery.

Page 10 of the executive summary states that the external costs are hard to quantify. While I welcome the delegates and appreciate their efforts to explain everything, those words are a damning indictment of their report. The report does not take cognisance of societal costs, indirect costs, tourism revenue, property devaluation or a delay in the implementation of the project, with all the economic implications for the country. I would appreciate a response on that. I could spend half an hour discoursing on the societal difficulties that will arise. It is a damning indictment of the report that it states, "External costs are hard to quantify and are not in fact quantified." While I take the point that the report is centred on international comparisons and has an abstract quality, it does not seem to me to be legitimate or sufficient that a report of this gravity should have abstract international qualities. It needs to be much more focused and site specific.

Page 185 of the report states:

The Forced Outage Rate is highly influenced by design. Particular UGC configurations e.g. in accessible tunnels promise a substantial reduction and effective control of risks..... A reported figure for the forced outages of underground cables has to be interpreted with extreme care..... Once in a while there are failures.

Based on those references in the report, is the repair argument about underground cabling greatly exaggerated?

Trench digging in urban areas is clearly difficult, relative to the terrain of Meath or Cavan-Monaghan. We do not need to be rocket scientists to work that out. The report says security of supply is critical, especially in dense urban centres. That being the case and we maintain underground cabling in urban centres, could we not do something similar in more benign territory in the country? I am asking these question on behalf of people who are very concerned about these issues.

The report states there are lower losses in the transfer of electric current through underground cabling. I would like a comment or an evaluation on that. That is significant because if energy is preserved at a greater dimension underground, surely that has merit. The sincerity and competence of those who compiled the report is not an issue. We are too serious about our business to challenge it on that level. I am concerned about the terms of reference, or how they were interpreted. I do not think it is adequate that an Oireachtas or Government body should be looking at a "desktop analysis". Even the €700,000 cost per km is based on international analysis. I am very concerned that none of this is site specific. I would think that much of the land to be crossed over is very negotiable and could very easily be tunnelled. I come from a background that gives me an appreciation of this. I would not have thought it was a major engineering, scientific or costly feat to install underground cabling in flat terrain.

While I am open to correction, it has been put to me that Ecofys did not analyse the three routes proposed by EirGrid. With the greatest of respect to EirGrid, that is a questionable position from which to have started, but that is a different debate and EirGrid will deal with that issue. However, local interest groups have suggested to me that although EirGrid proposed three routes, Ecofys performed its analysis on two proposed routes. If true, this would be of great concern and I would be pleased to learn it is not the case.

I commend Deputy Thomas Byrne on his suggestion regarding the option of international tendering. Obviously the tender would be somewhat vague, in that international tenderers would be obliged to tender for both the overground and the underground options. Such tenders then would be analysed before a decision was made. This point has been raised previously. While I do not suggest this was not an original thought on the part of Deputy Byrne, the option was raised with me by an elected colleague from my locality, Councillor Sean McKiernan, while travelling to Dublin today. He commended such an exercise to me and suggested I should recommend it at this meeting. I seek the witnesses' response to this.

Deputy Thomas Byrne

Great minds think alike.

Senator Joe O’Reilly

Both Deputy Byrne and Councillor McKiernan have great and finely trained minds. How would the experts respond to the suggestion that international tenders should be sought for both the overground and underground options and that the submitted costings should be examined thereafter?

My final point is raised at all the meetings on this issue. My four public representative colleagues in the Visitors' Gallery, as well as the Oireachtas Members here, are more than au fait with the arguments regarding the health issues that arise every time. Did the witnesses factor into their analysis that internationally the best practice is to use the precautionary principle when there is a doubt in respect of health? While I take Dr. Burges’s point on UN standards, should one not be concerned with the precautionary principle that when people’s health is in jeopardy or in doubt one should choose the reliable option? The concern people have about their health, irrespective of whether it is grounded in logic, is in itself of great concern. The witnesses should address this and my other questions. They arise from my genuine concern and the concern of those whom I represent who are highly anxious to find a sensible outcome in this regard.

Senator Jim Walsh

Like other speakers, I concede that I am not sufficiently technically qualified to assess the full remit of the report. However, it appears the issue must be broadly evaluated under three main headings, namely, technical, economic and environmental. Although health appears to be included under the broad environmental heading, it should be dealt with separately.

On the technical side, the main issue appears to be the forced outage rate mentioned. On that score, Ecofys comes down heavily in favour of the overhead lines. However, I noted that its report qualified this preference by stating it can be "highly influenced by design" in respect of the underground systems and the configuration involved. The report mentioned tunnels and the witnesses should clarify whether they are natural or constructed. What other configurations are relevant to this project would correct the outage rate balance tilting to the overhead lines?

I understand this line will be 70 km to 80 km in length and a comparison has been made between alternating current, AC, and direct current, DC, in this regard. Can the witnesses outline what are the implications, for both options, of making multiple connections? I presume this would not be a problem with AC, but would DC have implications for connections in terms of renewable energy and the transmission and distribution of electricity? Unfortunately, I could not find my notes from our meeting in Belfield. Given that they were pertinent to some elements of this discussion, I am at a disadvantage.

On economics, ecofys seems to be of the same strong opinion as others, including UCD, that there is a significant disparity in the cost of underground and overhead lines. It makes a slight qualification to the effect that depending on performance assumptions from limited experience the disparity may be mitigated. Our guests claim that the limited nature introduces uncertainties and may increase the cost difference further. To invert the claim, is it possible that the uncertainty might reduce the difference? We do not seem to be clear on this score.

In environmental terms, the decision would need to be made in favour of undergrounding. As most would acknowledge, overhead cables are a blight on the landscape. Regarding electromagnetic fields, our transmission systems are primarily 220 KVA whereas the proposal is for a 400-500 KVA system. The implications may be different. While the underground field strength might be higher than its overground counterpart, is there a narrower corridor for it? Through mitigating factors is it possible to decrease the underground field to almost negligible levels? Will our guests expand on these issues? Are there significant cost implications and can it be done readily or easily?

The witnesses claim that the magnetic fields of overhead lines can be reduced via a dedicated tower system. This is a critical factor with health implications. Despite ploughing through the report, I have been unable to find something in the terms of reference, namely, possible health issues. I cannot find a comprehensive analysis, although I may have missed it. Will our guests refer me to the comparative health analysis, a significant factor in the decision? They made an interesting point on policy implications, namely, that global legislation is becoming more stringent and complex. Will they spell out the range of factors involved? They stated: "This shift in the development of policies implies that simply complying with existing policy could be a potential risk as new, interrelated policies emerge." Will they expand on this statement, which is a significant part of the report?

Deputy Rory O’Hanlon

I apologise for leaving for some time. I am a member of the Joint Committee on Health and Children, which was holding an important meeting next door.

No one doubts the need for the interconnector. Were our guests to build the connector, would they place it underground or overground? For what technical reason would they not place it underground? Is it economically viable? All of the people I represent want the cable underground, as do I. However, I want to be satisfied that doing so would technically and economically be the right way to go. I do not have a problem with the health issue and never did. I accept the standards laid down by the WHO, the EU and the International Commission on Non-Ionizing Radiation Protection.

The other question concerns an alternate route, a North-South connector along the M1 or, better still, under the Irish Sea. The people I represent want it underground, the rest of us want it underground, but I make the proviso that it must be technically the right thing to do and economically viable.

Dr. Karsten Burges

I thank the committee members for their questions. Some issues recur in the questions asked. I refer to the reliability issue and the potential options of reducing the forced outage rate of underground cable connections. The report indicates that if one has underground cables in a tunnel, accessibility is dramatically improved and this will have an impact on repair time. This would be an option to bring both options closer together. Such a tunnel has cost implications and we included the tunnel option in one of the slides in our presentation and in the report, before the DC options. The costs claimed are about the same as for a double circuit AC line buried in soil.

The costs of such a structure are very hard to assess on a generic level. Building a tunnel along 130 km across a country is quite speculative on a generic level. One must go to detailed planning and seek offers from industry. Soil conditions will influence the cost per metre of building such a tunnel in the country. This also holds for the suggested tendering of infrastructure on an international basis. One may do so, but it will only work for specific routings. No company will be able to give a cost for a generic distance, from A to B. That means that someone must outline the routing because it is technology-dependent. I doubt one can distinguish these parts of the planning process, having an industry offer for a connection, regardless of the routing, which must be put in public responsibility. Perhaps the most important statement I can make is that I am confident the cost figures provided in our report are realistic. I believe that the offers one would get from industry are close to the figures we provided. There would be an enormous difference in the costings for underground cables compared to overhead lines.

We were asked whether the underground cable could be even cheaper than we assessed but we made a realistic rather than conservative assessment of the cost of underground cables. It is not just a question of a metre of equipment, which may be cheaper next year. It is also a question of the costs of burying the cable, crossing obstacles such as rivers and so on. Those cost components are unlikely to decrease dramatically in the near future. From that perspective, it is very unlikely that one would end up with lower costs for underground cabling than those indicated in the report.

Members asked about the differences in figures between various studies and the different technical characteristics referred to in other contexts. I must stress again the distinct nature of this technology. We are referring to 400 kV AC cabling in most of the report. This is a technology which is quite young and which cannot be compared to existing underground cables. A trench for such a cable must contain three single cables of a certain diameter, which cannot be delivered in lengths of more than approximately 800 metres because, at that point, the cable weighs 40 tonnes. It is not just a cable one pulls into place, which is what one would do with DC cables, which are much smaller. One must bury it well, make the connections and joints well and then move on to the next 40 tonne, 800 metre section. This does not compare to 100 kV or 132 kV cables, which are delivered in longer sections and which comprise three conductors in one cable. The technology to which we are referring is very different, which explains why references in many other studies simply do not apply to this discussion. Perhaps I was not clear enough on that point in the beginning.

Mr. Conor Wall

I wish to respond to Deputy Byrne, who questioned our independence.

Deputy Thomas Byrne

I did not question it, but wanted the witnesses to respond to those who have done so. The suitability of ecofys to carry out this study was questioned by campaigners.

Mr. Conor Wall

I will speak on behalf of Golder Associates and perhaps Mr. Burges will speak on behalf of ecofys. Golder Associates engaged in the tender process and went through the submission of a joint tender with ecofys. We have worked with ecofys in various countries around the world. Both companies are international consultants. In Ireland, we have over 100 employees. We went to an interview and won under standard procurement methods. Golder Associates Ireland has not worked for a transmission operator to date. We have a lot of experience in many areas of work, including mining, quarrying and waste management.

Dr. Karsten Burges

Ecofys is also an international consultant with offices throughout the world. We have done work in Ireland for Sustainable Energy Ireland and have been involved in the all-island grid study. However, in regard to this contract, we have not been subjected to any interference and I can assure the committee that we are acting as an independent consultant.

Mr. Conor Wall

I agree with Dr. Burges's response to putting a development such as this out to tender. In the absence of a detailed engineering design, it would be difficult to prepare a quote or costing.

With regard to Senator O'Reilly's claim that we did not investigate the three routes proposed by EirGrid, our assessment could have been biased towards a particular type of topography if we had only studied one or two developments without considering the future requirements of the transmission network over its 400 km route. Ours was a comparative assessment which attempted to take account of all aspects of the environment for both technologies. It is up to the decision maker to apply the knowledge gained from this tool to a particular submission.

Mr. Bill Sheridan

In response to the question on policy, the report has principally considered national policies within Ireland and has found little meaningful difference between the technologies. However, it has noted the trend towards an increased influence of international policies and legislation on the wider policy context. It simply notes for decision makers the importance of considering that in the context of future decisions. This point relates to an earlier suggestion that the report is forward looking rather than retrospective.

Senator Jim Walsh

Mr. Sheridan's comment is predicated on what the report describes as a shift in the development of policies.

Mr. Bill Sheridan

Yes.

Senator Jim Walsh

He gives the impression that he is making a general comment but in the context of the report that appears to have some relevance. I am trying to elicit that relevance.

Mr. Bill Sheridan

The relevance is simply that the international dimension is becoming more important in terms of trade and the open market. These factors mean that the network as a whole will have to be considered when choosing between technologies.

Dr. Karsten Burges

When speaking about security of supply or better transmission system adequacy, we have to be specific. This terminology does not mean that a loss of load from outage of components or assets is not allowed in parts of the network. Specifically, transmission system adequacy means that the system as a whole has to survive the loss of a component. This is what is known as N-1 security. If one component is lost, supplies should be maintained. If two severe disturbances occur simultaneously, the system should still survive. There may be a loss of load but the system should not collapse. We are not talking about losses of supply in parts of the country.

Transmission system adequacy means the supply of the whole country and assumes EirGrid's ability to keep the system operational, but this is something completely different. As with any technical asset, sections of the network may malfunction, which may have consequences for people in the area. However, none of those assets is in a part of the system which would threaten the operation of the system as a whole and this is a huge difference we highlighted in the report. The North-South interconnector would have such a dimension and this has to be taken into account in assessing transmission system adequacy.

Deputy Simon Coveney

I wish to clarify that point as it is important. The difference is between a 110 kV line which has a fault and needs to be repaired and a 400 kV line which is part of the backbone infrastructure. Is Dr. Burges saying that if there was a break in the line, whether underground or overground, it would affect the electricity supply over the entire national grid?

Dr. Karsten Burges

Yes. I will try to explain it to non-technical people. The system is designed so that if an asset is lost, the power will flow another way and will reach consumers. If two assets were lost it may be critical. The system is designed to survive those situations and recover but it may become critical. The backbone carries power and this power will look for another way to get from A to B.

Deputy Simon Coveney

There is a circuit.

Dr. Karsten Burges

That is the point which needs to be taken into account. It means additional power comes from another route.

Deputy Simon Coveney

With respect, I do not think we have received an adequate answer as to why we would have a system breakdown if it went underground rather than overground. Dr. Burges said technology sometimes failed but that is not an adequate answer. Is it because the lines could melt if there was too much electricity in the system? Is it because somebody might interfere with the line and break it? I presume whoever laid the line would put it in a strong casing. I have a difficulty with the reliability issues outlined by Dr. Burges and I am not convinced. He needs to explain why an underground line is more vulnerable than an overground line.

On page 83 of the report it makes quite clear that Irish and UK conditions mean overground lines are more vulnerable than anywhere else. We have many outages from our overhead lines but they are corrected quickly. The underground lines will be more protected from the weather so outages are less likely to happen but the key issue is the response time.

Is there not a halfway house between building a tunnel and burying the cable? I presume there are ducting systems in urban environments. Cables are not just buried but can be put through ducts and wires can be pulled through them when repairing or changing them without having to dig up whole sections of roads. I do not have a clear enough understanding as to why there is a such a problem with maintenance of and access to these lines when the cables can be laid through ducting systems, as with a fibre optic cable. Am I missing something? Is there a technical reason that ducting is not appropriate for what we are talking about?

Dr. Karsten Burges

I will go back to the reliability issue. This is a probabilistic measure, which means one is calculating with statistics. It is not a fixed figure which can be given for different conditions of the system. Assessing transmission system adequacy takes into account a significant number of possible conditions of the system and considers what happens if one or another asset is lost.

From that perspective, the difference in repair times is quite substantial. If there is a short interruption in the winter peak, in simulations one can see very little likelihood that the system may become vulnerable in a condition where it must carry the highest power. If there is a breakdown which exists for two weeks in December, it becomes deterministic; as a result of the extended period, by definition there will be a peak situation in such a case. This is the fundamental difference. If the problem could be repaired in hours, one could see there is a risk of getting in trouble but there would be many cases where it would not be felt. Is that clear?

Deputy Simon Coveney

I think so. I do not see what is likely to cause the problem with regard to underground cabling. The diagram on transmission adequacy is the key to the whole report as we can argue over costs with regard to what factors are included and excluded, whether the cost as indicated by research in Germany is correct or whether the delegates are correct. Reliability is my big concern. If EirGrid cannot rely on an underground infrastructure, there is a difficulty.

I am trying to gain understanding as to what is likely to cause reliability problems in underground versus overground systems. In that regard, the biggest box on the graph refers to JacobsBabtie 2005 and it is very different from the other reports. I am not sure what "FFC" means in this regard, although I am quite clear that all the others relate to underground cable or overhead lines. The FFC is totally different from the others.

If we disregard the FFC line and the other--

Dr. Karsten Burges

APG

Deputy Simon Coveney

The others would look much more attractive versus the Irish scenario for the overhead line, which represents a bigger problem for overhead lines than in most other countries. I presume we have more windy conditions here and so on. Perhaps the witness will clarify that.

In language we can understand, what is likely to cause outages or the need for repairs in underground lines with the technology being developed at the moment? I presume they are encased in very sold plastic or fibre optic cable and some kind of concrete ducting, which can be pulled through and changed if there are problems and so on. I am trying to understand that aspect.

Clearly, there is a political perspective and we want to put this underground if possible. That is what people want. If it is not possible to do it, we must be honest about it. I need to be convinced on the reliability issue, rather than just look at graphs. I want some practical examples from the urban setting.

Considering the figures, many countries have hundreds of kilometres of kV line, which I presume are in urban settings. There are 536 km in the US and 166 km in the UK, while Spain has 80 km, and so on. What is causing outages on those lines? Do we have any accurate data on that in order that we can understand the problems that may arise if we push to have this infrastructure placed underground?

Dr. Karsten Burges

The graph shows the likelihood of an unplanned outage - how often it happens. For overhead lines, the figure is 0.01 per km per year, which means that the likelihood of failure along a particular kilometre of line is once in 100 years. This is an impressive degree of reliability. This refers only to failure of equipment; there is no need for interference from the outside. Once in 100 years is an impressive figure, and the industry is busy trying to improve it. Members are looking for explanations regarding the vulnerability of these lines, but they are not vulnerable; they are quite reliable. Taking into account the repair times and the level of reliability we expect from our system, there is a difference for overhead lines, which is significant.

With regard to measures to reduce repair times by construction means, a tunnel would clearly increase accessibility. However, a duct would most likely not add value for two reasons. The first is that the line consists of pieces of cable 1 km in length which cannot be pulled out as a whole. To get the line out requires excavation of 1 km at both sides. In addition, the thermal characteristics of a duct are much worse than those of soil or, even better, concrete, which removes heat from the cable. This means that if using ducts the cables would have to be placed farther from each other, which increases the magnetic field and therefore increases losses. Thus, we can do this only if there is clearly added value. There is also a third point. If there is damage to a cable carrying such a huge amount of power, the duct will also be damaged, which will not help in repairing the cables more quickly. That is why a tunnel may make a difference but any other in-ground construction means that digging must be carried out in order to repair the lines, which means repair times are extended.

I am not saying there has been no progress in terms of technology. The transmission system operator will have people ready to go out regardless of the time of day at which the outage occurs, but more work is required to fix these cables compared to overhead lines. I am convinced this will remain the case as new technologies are introduced in the future, because there is a difference between the two types of line.

Deputy Shane McEntee

Based on this report, ecofys has quite clearly come down on the side of maintaining it is too expensive to go underground, yet Dr. Burges feels that part of the study could have been extended to include a more practical investigation as well as a desktop study. There are another 600 km of lines to be installed. Does he think the people of Ireland should accept at this stage that overhead lines should be used, or does he recommend that we do a proper study? I must be honest - I think today is a waste of time. Let us call a spade a spade. I consider the whole thing a waste of time because only a desktop study has been carried out. We know the lines can be placed underground but proper figures have not been obtained. We have had three presentations which have given contradictory information. Nobody can clearly state the truth.

Deputy Seymour Crawford

I agree to some degree with Deputy McEntee. There has not been an in-depth study of the terrain through which this cabling must go. It is clear that it can be done but the costing is neither adequate nor clear. We discussed the possibility of this setting a precedent and that if it were done, whether as a consequence all other lines constructed in the future would have to be the same. Surely it would not be a problem to make a political decision to only put 400 kV lines underground. Lower voltage power lines do not have the same exposure in respect of health concerns. There is a line from Tandragee to Ballykelly. We mentioned shock outages. Certainly there have been outages on that line for many years. Might it have been upgraded? The pylons are already in place to carry the 400 kV line and if that had been done, it would have saved us discussing the matter in the past few months.

We are not here to be awkward or difficult. We are here because people are genuinely very worried. One thing that still bothers me is the health issue I raised. We have not been answered, although there are various studies. What study did the delegates conduct of health concerns and what guarantees can they give on this matter?

Senator Joe O’Reilly

I do not propose to repeat the points I made. Briefly, I am concerned that we have a site-specific study that will take account of the terrain. We have not properly engaged with the prospect of placing lines underground in that context. I acknowledge the contributions made by our guests but share the concerns of my colleagues. We must go further. Executive decisions could not be based on what we have learned to date.

Deputy Thomas Byrne

I was out of the room but listened to the debate on the monitor. I do not agree that this meeting, or the report, have been a waste of time, as Opposition colleagues have suggested. For those of us who wish to see the lines being placed underground a report such as this gives us extraordinary hope. Last year EirGrid told us it was not possible to place the cables underground but we have now been told that this is technically feasible and have been shown concrete examples of such work done in other countries, including Germany. In other countries there is a political move to place such lines underground wherever possible. If people want to have lines placed underground, they have political power.

We seem to be at a very early stage in the development of the technology. The point was made that ten years ago nobody would have bothered producing this report because the alternative technology simply was not available. What will be the situation in one or two years? We must also bear in mind the length of time it may take to complete this project.

I am very hopeful and believe the meeting has been very worthwhile. I have been interested in the responses. We have a long way to go and there is a great deal of work to be done in learning about the technology and recognising the pressures on EirGrid to do what the people of County Meath wish it to do. It is not fair to say the meeting has been a waste of time.

Chairman

Before I return to Dr. Burges, I seek clarification on one issue. When Oceanteam gave evidence to the committee, its managing director stated the difference in cost between overhead lines and underground cabling was only marginal. Will the delegates comment on this? The debate is coming down to the question of the actual cost involved. The delegates have stated clearly and members understand from their report that it is possible to place cables underground but that the matter is one of cost. There is a clear difference between the evidence of the delegates and the statement of the managing director of Oceanteam. The committee is to examine the international work of Oceanteam. I would like to be able to ask Oceanteam about this major difference of opinion between Dr. Burges as a consultant and Oceanteam as the practitioners on the ground.

Dr. Karsten Burges

I am aware of the discussion that took place with Oceanteam some weeks ago. The point is that, having declared that the cost difference would be marginal, its president, Mr. Rory O'Neill, indicated the costs to be expected for a 67 km line would be €250 million to €280 million. That is an investment of €4,000 per metre which is at least a factor of four compared to what it would cost for an overhead line. In my view, that is not marginal. The figures are his, not mine. The last slide shows that the uncertainties in those cost claims are high. However, the point is that these are only investments. What I have tried to explain is that the losses associated with the power conversion in DC technologies are significant. This is an issue on which I suggest asking ABB or Oceanteam-IMERA for clarification. I am convinced they will come up with similar figures.

Chairman

Perhaps you might address the other questions that have been raised.

Mr. Conor Wall

One of the members mentioned an upgrade from a 200 kV to a 400 kV line. Could he repeat the question?

Deputy Seymour Crawford

The current interconnector between Ballykelly and Tandragee in Northern Ireland is a 250 kV line. What would Dr. Burges's comment be on upgrading that to a 400kV line?

Dr. Karsten Burges

This is a question that must be addressed to EirGrid. I am not in a position to judge what that would mean for this line. Most likely it would mean other towers would have to be built because of the higher voltage. It is not just a case of adding transport capacity to the network. There may be reason to have a second path in the network. From that perspective an upgrade would not help. It is a question EirGrid must answer.

Deputy Seymour Crawford

Dr. Karsten has not addressed the health issue.

Senator Jim Walsh

Some of the questions I asked were not answered. I will put one of them to Dr. Burges now. Where in the report is there reference to the comprehensive analysis that should have been done on health?

Dr. Karsten Burges

Health physics is a specific area of science. We took the international standards as a reference and looked at the technology implications the options have compared to these standards. We did not challenge the international standards. This would be far beyond the scope of even a national study. The precautionary principle was mentioned. It is an acknowledged principle in policy making. Even then one must agree on the level considered acceptable. Otherwise, one will end up in natural exposure and having to mitigate the impacts completely, which is not possible when implementing any infrastructure. Consultants would end up with an arbitrary value we would consider acceptable, which would be a highly disputable assumption in such a report. That is the reason we referred to the accepted international standards.

Senator Jim Walsh

Dr. Burges was specifically asked to examine the implications of the health issues. That is the point I am making. I cannot find any response to that term of reference in the report. Am I wrong? I concede I may have missed it but if Dr. Burges can reference where the report has dealt with that term of reference - I do not even want an answer now because we can read it subsequently - I will accept that. He might give me the page numbers that deal with that.

Chairman

Dr. Burges might get back to Senator Walsh on that item later.

Deputy Simon Coveney

I do not want to labour the health issue. Health is mentioned in the terms of reference but it is not one of the main factors. One of the headline issues in the media coverage of the report when it came out was that exposure to magnetic fields may be higher directly above underground cable than under overhead lines. Deputy Crawford has raised this issue already and it is important to put people's minds at rest on it. My understanding is that by putting lines underground the exposure to magnetic fields is dramatically reduced because it is, essentially, insulated in the ground. Is that not the case? Is exposure to magnetic fields increased by putting lines underground or overground? If that is the case I would find it extraordinary considering that most of the lines in the highly populated urban areas are put underground. I would like some clarity on that issue.

Deputy Seymour Crawford

If I may come in before Dr. Burges responds, the discussion at the outset was to the effect that it was quite safe to be within 50 metres of the lines. Monaghan County Council, the local body in my area, decided that should be increased to 100 metres but in this report, not mine, on the German position the figure is 200 metres from single houses and 400 metres from residential areas. It is unacceptable to say that health is not an issue. It is an issue, and the divergence between what we are told is safe and what is stated in Dr. Burges report is significant. I refer to page 50.

Dr. Karsten Burges

Two issues arise. The point I wanted to make when showing this graph is that magnetic fields depend on the design of a system in both cases. With a certain design of underground cables there are higher magnetic fields above the ground; it is not the ground that covers the magnetic fields. The difference between overhead lines and underground cables, in terms of magnetic fields, is quite simple. It is the distance of the conductors. The magnetic fields are stronger if the distance of the conductors carrying the same current is larger. Underground cables are normally put close together in the ground. That is the reason the magnetic fields of the single conductors offset each other and there is then less exposure above ground. If, for a thermal reason, there is an arrangement in place where the distance is larger, for example, those joints must be located somewhat further from each other to have space to work there the magnetic fields above earth will be higher. I do not say they will be higher than in the case of overhead lines. The key message is that it is not the value but proper design. If one wants to reduce magnetic field exposure, one must take that into account in the design. The lowest magnetic field has a cable arrangement whereby all three conductors are placed together. This is the normal case with standard AC cables for lower voltages because they are carried in one cable. However, this does not work with 400 kV cables. They cannot be put in close proximity in all cases because of the heat that is generated. The latter must be dissipated and that is why they are removed. It is really a case of finding a design balance. The point I wish to make is that one can, to a lesser extent, obtain this kind of design freedom with overhead lines. The design may still be optimised in respect of magnetic field exposure.

Deputy Crawford inquired about the fact that in Germany single houses must not be located within 200 metres of overhead lines. The levels defined in other countries came into place as a result of political decisions. Authorities in the Netherlands are considering lower levels in respect of permanent exposure. However, in all these cases, even the governments which apply those regulations clearly state that this does not mean they doubt the reasonable levels that have been set down by the WHO. It is a decision for those governments to apply lower levels without challenging the existing scientific evidence. That is why we were not in a position to challenge it either.

Chairman

I thank Dr. Burges, Mr. Wall and Mr. Sheridan for their attendance. I also thank members for their contributions.