Eamon Gilmore (Dún Laoghaire, Labour)
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Question 170: To ask the Minister for Communications, Marine and Natural Resources if he will report on the occurrence of a red alert in the electricity system in August 2005 and the doubling of amber alerts in the system during 2005; the measures he is putting in place to maintain security of supply; and if he will make a statement on the matter. [2106/06]

Trevor Sargent (Dublin North, Green Party)
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Question 187: To ask the Minister for Communications, Marine and Natural Resources his Department's views regarding the level and number of amber and red alerts that the energy regulator had to issue in the second half of 2005 due to the unavailability of existing generation plant; if his attention has been drawn to the reported recent operation of emergency generating plant for some 15 to 17 hours a day on a regular basis and the extreme volatility in the top up price that independent generators have had to pay for additional power due as a result of this capacity problem; and if such volatility will discourage new entrants into the Irish electricity market. [2191/06]

Noel Dempsey (Meath, Fianna Fail)
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I propose to take Question Nos. 170 and 187 together.

Security of supply in electricity is a matter for the Commission for Energy Regulation in accordance with the provisions of Article 28 of the European Communities (Internal Market in Electricity) Regulations 2005. Article 28 provides that it shall be the duty of the Commission to monitor the security of supply of electricity and that the Commission shall take such measures as it considers necessary to protect security of supply.

ESB National Grid has provided the Commission with a report on the investigation into the electrical system disturbance on 5 August 2005 which led to the temporary loss of supply to 326,000 customers in Ireland and a further 74,000 customers in Northern Ireland. The report notes that the power system was being operated normally prior to the incident and identifies a primary cause, a secondary cause and a third contributor to the incident. The primary cause is identified as an incorrect detection of separation of the electrical systems North and South and the secondary cause is identified as an incorrect operation of the Moyle interconnector run-back scheme. These causes resulted in an import from Scotland of 115 MW turning into an export of 416 MW causing a deficit on the island of 531 MW. The report also identifies a third contributor as the subsequent performance of three large ESB-owned generating units at Moneypoint and Tarbert, two of which lost output completely in response to the initial disturbance.

The report notes that the underfrequency load-shedding scheme operated correctly in response to the disturbance and prevented power system collapse. The report concludes that the causes of the disturbance have been identified, that remedies are being or have been implemented and that a recurrence is highly unlikely.

The issue of alerts for the electricity system is a matter for ESB National Grid as the transmission system operator. ESB National Grid states that system alerts are internal industry signals to generators to encourage caution at times when the margin between capacity and demand is tight. They are used to reduce the chances of a failure of a generator which could lead to a shortage overall. ESB National Grid states that there have been no occasions this winter when electricity supplies have been affected by a shortage of capacity. However, it remains the case that the margin between capacity and demand for electricity is tighter than normal this winter.

The availability performance of some of the existing older ESB generation plant is giving cause for concern and has been for some years. Performance did improve in 2004 and during the first half of 2005. However, it declined again in the second half of last year as a result of the breakdown of several large ESB generation units. The resultant impact has been that at times during the winter the margin between demand and available generation has been and may continue to be lower than the design level.

The Commission has advised my Department that it is investigating concerns about significant volatility in the price of top-up electricity and the implications of any such volatility for existing independent generators. Pending the outcome of this investigation it would be premature to speculate on the cause and effect of volatile top-up prices for existing or potential players.

In the performance of its role in relation to security of supply generally, the Commission has secured the provision of two new generating stations, Aughinish Alumina and Tynagh Energy, with a combined capacity of over 500 MW. These new stations are currently being commissioned. Furthermore, the Commission informs my Department that Viridian has commenced the construction of a second generating plant at its Huntstown site which will provide a further 400 MW of capacity by the end of 2007.