Undergrounding power lines seven times more expensive, report says

EirGrid has published a study conducted by independent experts which they say has confirmed overhead power lines are the cheapest and most secure option for the planned power lines in the north east. The power company retained Parsons Brinckerhoff (PB Power) to examine issues allowing a comparison of overhead and underground options. PB Power has spent the last year conducting a comprehensive and site specific underground cable study for the proposed Meath-Cavan and Cavan-Tyrone projects. Tomás Mahony, EirGrid project engineer, says: 'Based on the requirements to provide transmission infrastructure that is safe, secure, reliable, economic, efficient and that has due regard for the environment, overhead lines emerged as a preferred option for the projects.' Mark Winfield of Parsons Brinckerhoff, a high voltage transmission expert and author of the report, says: 'The Report found that the cost estimate for an underground cable option is seven times more expensive than going overhead - €588 million compared with €81 million. It also found that underground cables would be more expensive to operate.' Based on the expected usage over its life time, it is estimated that the operating cost of the underground cable option would be €73 million underground compared with €44 million for overhead lines. The report also claims that, over their lifetimes, underground cable could be out of service for repairs for a combined period that is fifty times longer than that of the proposed overhead lines. It says this is because, while underground cables rarely fail, when they do, they will almost always require substantial repair work. In the case of a 400kV underground cable experience has shown that these repairs can take many weeks to complete, during which time the cable will be out of service. In comparison, most faults on high voltage overhead lines are caused by the weather and damage is rarely sustained. On the few occasions that such a circuit is damaged the overhead line can usually be repaired, and returned to service, in a matter of hours. The electrical and magnetic fields (EMF) from the proposed overhead line and the underground cable alternatives would comply with all national and EU guidelines on EMF, according to the Report. Parsons Brinckerhoff (PB Power) also confirmed that there is no underground cable circuit, of the kind and length required for these projects, anywhere in the world. Over 98 per cent of the onshore electricity network in Europe is overhead line, with the remaining being underground cable. Underground cables are mainly used over short distances, in areas where overhead lines are inappropriate or impossible to use. This trend, the Report states, is not likely to change in the foreseeable future. Campaign group North East Pylon Pressure campaign (NEPP) has rejected the findings as "fundamentally flawed". They say the headline figures for cost do not stand up to close scrutiny. "For the section of the proposed lines from county Meath to the border, the PB Power estimated cost is €432 million. This compares with the much lower estimate by the ASKON experts for NEPP OF €305 million. The report grossly overestimates the cost of operating an underground system and goes in the face of international expert opinion that, while underground may be more costly to build, it is always cheaper to operate than overhead. "We utterly reject the assertion that underground is more costly to build and operate than overhead." NEPP is "disappointed that this is yet another light weight report. PB Power spent only two days on the ground in the North East. Despite EirGrid"s commitment to the contrary, the PB Power costings are therefore based on a so-called "theoretical" underground circuit in the North East that will never actually be built and their calculations have no validity as a basis for decision making. "