http://www.climatechangecafe.com/tag/glinsk/ is a compassionate article which shows how the blanket bog of mayo is to be industrialised. The proposed saltwater hydro hilltop dams will be no-go areas , because the water levels will rise and fall at a very dangerous rate.
The effect upon the blanket bog will be destructive. The biosphere will be completely subverted.
The nearest examples of this technology are DINORWIC in Wales and TURLOUGH HILL in Wicklow. Neither of these draws sea water to the hilltop. The shorelines of the emptied dams can be seen exposed.
Dinorwic is drained in five hours of running, filling in seven hours.
Look at www.gridwatch.templar.co.uk to see the rhythm of this huge construction, with its very minor contribution to the UK energy budget.
How many such dams will we need around Ireland`s coast to make any real difference?
As Prof. David Mackay points out in his book, we have all this renewable technology, but we do not have enough countryside to fit it all in.