Ms Claire Quane:

I am happy to talk about SF6 gas. It is used as an insulator and is a very good insulator. It also has arc suppression qualities. If one flicks a light switch, one might get a spark which is fine but if the voltage is very high, it is very important to have an arc suppression medium in place when doing that. SF6 is good for doing that. That is why it is used around the world in distribution and transmission systems as an insulation. As a consequence, the equipment can be much smaller than if one was using a different medium. That is important when we are trying to build stations which are required in urban or other areas where land can be difficult to get. It is used all over the world for that reason.

SF6 is a greenhouse gas and we are mindful that we have to manage its usage. The F-gas directive was issued in 2006 and updated in 2014. We are constantly improving what we do. Some equipment that has SF6 gas has been on the system and in use for a long time. Moneypoint power station was built around 1980. This relates to the fact that we are always trying to get better at what we do. In 2015, we had a suite of management procedures on how to deal with and manage SF6 procedures. In addition, we are looking at our inventory. I spoke about our inventory of equipment and noted that we are keeping a record of the equipment we have. We are constantly improving in this regard, as I explained. Under the regulations in place at the time, information on the exact amount of gas in the switchgear was not required. All of our newer equipment is in compliance with the current regulations and it is clear exactly how much SF6 gas is in that type of switchgear. We are always trying to improve the inventory and that has been happening.

There is some leakage and we acknowledge that. The leakage rate in comparison to other international utilities has been higher. Part of the reason for that was the older switchgear that was put in place in Moneypoint in the 1980s. That has now been replaced by newer switchgear and we are already seeing the impact of that. When building a transmission station one needs a number of years to retire the old gear and bring in the new gear because it is a big job. Our usage of SF6 gas in 2018 was significantly less that it was in 2017 because we had already moved some of the circuits from the old Moneypoint switchgear into the new switchgear.

Ireland has 60 million tonnes of CO2 emissions. To place SF6 gas usage into context, it equates to 0.027% of Ireland's overall greenhouse gas emissions. That is not to minimise the fact that we have to manage it.