A Mayo View: EirGrid power plan welcome but pertinent questions remain

While news that EirGrid will start work early next year on the long-awaited 110kV project to improve the region's power capacity, some questions remain in regard to whether or not it will sufficiently meet demands into the medium and long terms.

The original proposal for the line in 2012 was a 400kV project, primarily planned as an overhead line.

This aimed to facilitate the significant level of renewable energy generation that was planned for the region at that time.

By June 2017, the amount of planned renewable generation capacity in the region had dropped by half, meaning a project on the scale of Grid West was no longer necessary.

Nine years on, however, one has to wonder if the original plan would have been better in view of all the new windfarms that have been put in place across the county since then.

This opinion piece is not designed as criticism of EirGrid or its investment by any means.

For the writer acutely remembers the wave of objections the company encountered at protest meetings when it first unveiled its plans.

Communities joined together to oppose overhead powerlines being erected across their parishes due to perceived health and other fears.

The 'Say No To Pylons' campaign was, to its credit, very effective and EirGrid had no option but to relent and revise.

Yes, we're all glad, I suppose, that further overhead cables have been eliminated from our landscape.

But, in reality, underground power lines have a lower current capacity than overhead lines due to what's described as 'heat dissipation limitations'.

This, I've learned, is because overhead lines are air-cooled, allowing them to release heat more efficiently, while underground cables are surrounded by soil, which traps heat and limits the amount of current they can carry. This means overhead lines carry higher voltages and more power.

According to EirGrid’s own documentation, underground cables don’t get damaged or break any more often than an overhead power line. But when they do, they are usually out of service for much longer while the problem is found and fixed. This impacts the reliability of the grid.

While the new plan is to be embraced, the point remains that it may prove short of what Mayo really needs for it to thrive and prosper into the future.

If that proves to be the case, then it will be very disappointing.