Report: Overhead electricity lines safer than underground ones

A REPORT commissioned by the Government has found that overhead electricity lines are safer, more reliable and cheaper than their underground equivalents.

This is despite public campaigns to have all cabling placed underground owing to safety concerns.

The study, initiated in February, was conducted by international consultants Ecofys and Golder Associates, a global group that specialises in ground engineering and environmental services.

As part of the study, they received 522 submissions and carried out two case studies on route lengths of 100km and 50km.

The study found that while there was increasing pressure internationally for underground cables as an alternative, there were a number of drawbacks, including:

* International experience of laying such cables over long distances is limited and the majority of existing projects do not represent transmission connections in conventional networks such as those in Ireland.

* Underground cables can be expected to have forced outage rates that are at least 10 times greater than those of overhead lines. Therefore, they have inferior security of supply.

* Work undertaken on the two case studies suggests the capital cost of constructing underground cables would be about five times greater than the cost of overhead lines and three times the lifecycle costs.

* Exposure to magnetic fields may be higher directly above an underground cable than under overhead lines.

Energy Minister Eamon Ryan said: “The study demonstrates that decisions on these kinds of projects need to take a wide range of complex technical, economic, environmental and other considerations into account. My department will now arrange for the consultants to present their findings to the Joint Oireachtas Committee on Communications, Energy and Natural Resources.

“I am confident that this study will assist all interested parties in current and future transmission projects.”

However, Joe Burke of the Bantry Concerned Action Group, which successfully campaigned against overhead cables on local lands, said the study was commissioned by the Government to back the cheapest option for itself.

He said the European best practice was underground cables.