Pat Rabbitte (Dublin South West, Labour) | Oireachtas source

I propose to take Questions Nos. 8 and 34 together.

Electricity demand must be met by generating the exact amount of energy required at any point in time. The responsibility for maintaining this balance between demand and supply is managed in real time by EirGrid, the independent electricity transmission system operator. To deliver on this remit, EirGrid's operation of the electricity system includes the day-to-day planning of availability of generation plant, both conventional and renewable, to ensure power flows on the electricity grid are managed reliably and securely. On an ongoing basis, EirGrid also plans and develops our electricity transmission infrastructure to enable the integration of sufficient renewable energy generation to allow 40% of electricity demand to be met by renewable energy by 2020, a key element required to meet Ireland's EU target of 16% of our total energy demand being met from renewable sources by 2020.

The balance between supply and demand and the stability of the electricity grid are managed by EirGrid at its national control centre in Dublin. System frequency is an indicator of success in managing the supply-demand balance. On numerous occasions in recent years, the amount of variable wind power on the system has been over 50% and system frequency has been successfully managed.

A number of major studies have been carried out by EirGrid Group in recent years to investigate the levels of renewable generation that can be securely accommodated on the power system of Ireland and Northern Ireland. These studies have considered the implications for both transmission infrastructure and grid operation of managing a power system with large amounts of variable renewable generation sources. On foot of this work, EirGrid has developed a range of secure operational tools and system management policies to manage the power system with increasing amounts of variable renewable generation. These operational tools and polices are subject to ongoing review and development to ensure security of supply is always maintained.

EirGrid's work in this area, in which it co-operates closely with SONI, the system operator for Northern Ireland, began with the carrying out of the all island grid study in 2008. This was followed by the facilitation of renewables study in 2010. These studies provided the basis for EirGrid's programme, "Delivering a Secure Sustainable Electricity System", also known as DS3. A number of work streams are underway in the DS3 programme, including on frequency control. With regard to the specific issues raised by Deputy Colreavy around frequency control, he may wish to consult the report produced as part of the DS3 project Summary of Studies on Rate of Change of Frequency events on the All-Island System published in 2012 which is available on the EirGrid website.

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