I propose to take Questions Nos. 85 to 87, inclusive, together.
The discount rate used by EirGrid for investment appraisals and feasibility studies has been informed by and is consistent with regulatory determinations. The Commission for Energy Regulation recently determined the regulated real pre-tax Weighted Average Cost of Capital as 5.95%.
The time horizon used by EirGrid for investment appraisals and feasibility studies has been informed by and is consistent with regulatory determinations. In this regard, the Commission for Energy Regulation has recently determined that the Regulatory Asset Base would continue to be depreciated over 50 years.
The planning, development and routing of transmission line infrastructure is a matter for EirGrid, which is the State owned body responsible for the electricity transmission system. I have no statutory function regarding the planning and construction of energy networks.
However, I can confirm that there are two existing 110 kV cross border circuits connecting between the Republic of Ireland and Northern Ireland. One circuit connects Letterkenny in County Donegal to Strabane in County Tyrone; the other connects Corraclassy in County Cavan to Enniskillen in County Fermanagh. The 110kV network on both sides of the border, in these border counties, is relatively weak and the two 110kV cross border circuits were installed in order to provide emergency local support in one jurisdiction in the event of a problem in the other.
They operate as standby circuits and do not carry power under normal circumstances.
The quantity of electrical power that can be transferred via these existing cross border 110 kV circuits is constrained not only by the power carrying capacity of the circuits themselves but also by the weak 110 kV network into which they connect, on both sides of the border.
To increase the power transfer capacity of the existing cross border 110 kV circuits would therefore require an upgrade of not just the circuits themselves but also an extensive and deep upgrade of the 110 kV networks in both jurisdictions. Implementing such an upgrade by increasing the voltage rating of the existing circuits up to, say 275 kV, would require a re-build of the networks on both sides of the border. This would require such prolonged outages in the areas concerned that, even if such a rebuild of the network was feasible from an environmental and public planning perspective, it cannot be considered as a practical proposition. As a consequence it was not considered as an option in the joint feasibility studies carried out by EirGrid and Northern Ireland Electricity during the years 2001-2005.
The 2001-2005 feasibility studies were recently reviewed by EirGrid as part of its project re-evaluation process. The findings of this review, published by EirGrid in its Preliminary Re-evaluation Report of May 2011, confirmed that the most appropriate option for achieving the required increase in the capacity of North South Interconnection remains the installation of a new high capacity 400 kV circuit connecting between the existing Woodland Substation in County Meath and a new substation at Turleenan in County Tyrone and routed via the vicinity of Kingscourt in County Cavan.
In July 2011 the Minister appointed an expert independent international commission to investigate the case for undergrounding all, or part of, this proposed 400 kV circuit. The Commission is expected to report its findings in the near future.
