I am not sure about all of EU, but Sweden is connected to most neighbours (at least Norway, Denmark, Germany,  Poland and Finland (additional cable from Forsmark to Åbo being built this summer by a Norwegian company)) and except for Vattenfall's manipulations, it appears to work fine both technically and institutionally.

If the same is true for all non-island EU states as I think it is, connecting Ireland into the existing framework should be easy.

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