Turning the Tide in Wales?

Wales has huge potential for generating renewable marine power. Tidal energy is actually much more predictable than wind and solar alternatives. The European Union's Regional Funding Programme (probably Wales' last from this source), has given a £31m grant. The project involves placing turbines on thirteen square miles of the sea bed between Holy island and Anglesey, in North Wales (https://www.theguardian.com/environment/2022/apr/24/could-angleseys-tidal-energy-project-drive-a-new-energy-revolution). The development, when it becomes fully operational, could power 180,000 home in the area. This would be a clear illustration of tidal energy's potential to reliably generate electricity (hopefully, without environmental damage). The poject has rekindled talk about constructing lagoons with integral turbines. Wales has some of the largest tidal ranges in the world. Lagoon constructions, however, require energy. A costs versus benefits calculation is needed (as is the case for hydroelectric projects). You have to determine how long a development has to function, before there is a net gain in energy. Rather obviously, in the case of lagoons, the potential impacts on marine life would also have to be carefully monitored and assessed.