Friday, November 10, 2017
Why putting our cables on a third bridge might not be as simple as it sounds
By Gareth Williams, Senior Project Manager
In recent weeks a number of people have raised the possibility of putting our connection on a new bridge to cross the Menai Strait rather than building a tunnel – this is something we’ve been discussing with Welsh Government for a number of years.
I can see the attraction of combining our connection with a new bridge. However, with plans for three massive projects (Wylfa Newydd, our connection and a third bridge) all happening in the same area in a similar time and relying on each other to a greater or lesser extent, you can imagine the complexity that brings.
Welsh Government is very focused on delivering a bridge to a challenging timescale with a clear eye on its cost and we understand they have secured development funding. Even with the application for Wylfa Newydd not being submitted until next year, we believe that there are still significant challenges that need to be overcome. We are working with them to understand the project, and what it could mean for us, but we need to have much more detail before we will know if it works for Welsh Government, National Grid and Horizon Nuclear Power.
It is not clear if there are any savings to be made by using a bridge rather than a tunnel. The cost of the cables themselves are tens of millions of pounds and there is also a question of how we divert from our current proposals to get our connection to the bridge, off the bridge and then to our substation in Pentir. This is not as easy as it sounds as it's a built up area around the current Britannia Bridge, especially on the Gwynedd side. We would need to take a careful look at how that would be possible and consider potential environmental effects.
We don’t know what the connection to and from the bridge would look like or the difference between our existing proposals. It could potentially require more pylons or undergrounding in areas. The balance between the visual impact of potentially more pylons, the construction impact of building a 60 metre wide trench for several kilometres, and the increased cost of a tunnel or underground connection begins to make this a challenge. It also calls into question whether there is a saving to be made. We expect that the stakeholders in the area would not want to see more pylons proposed and more construction impacts on local people.
It’s also been raised that if there were any savings from putting our connection on a bridge it could be used to put other parts of the proposals underground or contribute to the construction costs of the bridge. National Grid has to develop proposals it believes comply with planning guidance set by the UK Government and we then get permission from Ofgem to recoup that money from electricity bill payers. So any money not spent on one part of the project will not get allocated to another part, but will in effect not be added to all of our electricity bills.
This work is all needed for when Horizon Nuclear Power start generating electricity from Wylfa Newydd, supplying energy to millions of homes and businesses and unlocking billions of pounds of investment. It is our job to make sure a connection is ready for when that happens and we are working hard to make sure we do that in the best way that we can.