Mr. Garrett Blaney:

I will try to answer both questions. On the question of whether it should be built underground or overhead, this has been looked at on a number of occasions by a number of different bodies. The first report was done in 2008 by Ecofys, having been commissioned by the Government. EirGrid had its own analysis done by PB Power and this was published in 2009. An expert independent commission was set up by the then Minister, Deputy Rabbitte, and it published a report in 2012.

To clarify, the independent expert commission's view was that it was not technically possible to build this as an AC line and that it would have to be built as a DC line. To explain this difference between AC and DC, AC would work in anyone's house whereas DC is the voltage used in a phone or a standard device and is at much higher levels. Therefore, AC needs to be converted to DC in a very large conversion station, such as we already have for the east-west interconnector, which committee members can visit if they want to see what one looks like. There is a special cable for DC which is made in only a small number of factories in the world. This underground DC cable power is then transported to another convertor, which has to reconvert from DC back to AC in Northern Ireland.

There are physical characteristics that sort of sterilise the corridor between these two convertor stations. It does not allow any connections at that point, so it would sterilise that area for new investment. We are seeing - this will flow into the demand question - a lot of new data centres and very interesting new loads coming into the Irish system that are helping increase demand at the moment and that are also good for the economy in general, although our interest is primarily the impact on consumers. The HVDC solution is more expensive, and it was the view of the independent commission that it is typically three times the cost. Its view and international precedents show it will give less function than an AC cable, so one would pay more but get less.

Our concern is from a cost point of view, and this is obviously a significant increase in cost. We were in front of this committee previously on this issue and we have written to the committee setting out our view on the differences in cost between overhead and underground. If the three projects in Ireland were converted from overhead to underground, it could add something like 3% to the consumer's bill over the next 50 years. These are significant extra costs from a consumer point of view.

We also need to look at our statutory function. We are looking at this purely in terms of what we are set up to look at under statute, which is the cost to the consumer and the impact on security of supply. Obviously, land use, visual amenity and all of those planning issues are a matter for An Bord Pleanála. This has gone to An Bord Pleanála; my understanding is that it was submitted on 9 June and a consultation is starting today, run by An Bord Pleanála. It is helpful this committee is raising the profile and allowing all the affected parties to engage in the planning. However, we are limited very much to our statutory function and we obviously do not want to take a view on planning functions, given there is another statutory State agency there to deal with the planning function. We need to let it get on and do its job.