Tuesday, 11 March 2014

Ceisteanna (8, 34)

Michael Colreavy


8. Deputy Michael Colreavy asked the Minister for Communications, Energy and Natural Resources the studies that have been carried out into the uncontrollable changes in frequency by connecting large amounts of variable wind power to the national grid; and if he will make a statement on the matter. [11493/14]

Amharc ar fhreagra

Michael Colreavy


34. Deputy Michael Colreavy asked the Minister for Communications, Energy and Natural Resources if he will indicate the degree of sensitivity to which the national grid is to massive increases or decreases to supply and or demand challenges; and if he will make a statement on the matter. [11494/14]

Amharc ar fhreagra

Freagraí ó Béal (12 píosaí cainte) (Ceist ar Communications)

Does the Minister have a comment to make regarding wind energy? I know his Department has been studying wind energy extensively. One of the great problems anywhere wind energy is produced is the fact that we cannot control when the wind blows or the rate at which it blows. Has the Minister looked into the specific problems regarding those changes in frequency through the connection of a large amount of variable wind power to the national grid? What are the technical and other challenges that variations in frequency and the difficulty in predicting frequency pose in terms of connecting to the national grid?

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.

There is a good deal of information out there. Again, it is not light bedtime reading.

Was one of the drivers of the export energy project the fact that, given the uncontrollable changes in frequency in the Irish network, an excess could be exported to Britain? I am puzzled. If the wind blows in Ireland, it is also blowing in Scotland, Wales and the west coast of England. If we have uncontrollable changes in frequency leading to large amounts of energy in our national grid, surely the same would apply in Britain. If both jurisdictions have the same level of supply, or if there is none because the wind is not blowing, I cannot figure out how this project would work.

The answer to the substantive question is "No". The contemplated export project has nothing to do with excess capacity in the system. As that project has been planned, the requirement on the Government is to put in place the intergovernmental agreement that facilitates trade in green energy under the relevant EU directive. It is a private sector project and is entirely separate from the refurbishment of the transmission system. It is also a different technology, a DC subsea cable.

I am not competent to enter into a technical discussion with Deputy Colreavy on whether it is true that, when the wind blows in Ireland, it also blows in Scotland and England, but I am not entirely sure-----

I thank the Minister.

Do not cut me off in mid-flow. This could be a major scientific breakthrough. Deputy Colreavy knows that the wind can blow strongly in the west, yet it need not be blowing strongly here on the east coast. Similarly, there could be high winds in Scotland without there necessarily being wind in Ireland.

I will revert to the Minister and will not cut him off.

We may well be able to set up a task force to get to the bottom of this matter.

Along with the other reports. The point about AC-DC lines being bandied about is in respect of changes, interconnectors, etc. When I sought advice on this matter from technical people, many claimed that going from one to the other was not as major an issue as had been suggested. I am unsure as to whether the experts have advised the Department on the technicalities.

Is Deputy Colreavy satisfied?

Deputy Moynihan is correct. It is technically feasible, but the cost that comes with it is the issue. For example, one could run an AC cable and, upon reaching a particularly scenic area, nothing would prevent one from putting the cable underground, but it could not be for a long distance. Doing that would require a DC cable. Take something as simple as the Tyrone-Meath line. The international expert commission concluded that putting it underground would have approximately 3.1 times the cost of traditional AC overhead transmission. Deputy Colreavy referred to some of the other reports that have been done. They suggest that the cost would be even more. It is around that figure.

This is a major factor, but it is not the only one. After a year of study in Denmark, for example, and despite having no difficulty with affording such an approach and so on, it decided not to go underground with 440 kV cables for a combination of reasons, not just cost, but also technical considerations in term of how easy it was to find a fault, etc.

It is complex terrain.

Question No. 9 replied to with Written Answers.