Is this curtailment due to overproduction, curtailment due to inadequate _grid_ capacity, or some mixture? In Ireland there's now a _lot_ of curtailment, but it

Is this curtailment due to overproduction, curtailment due to inadequate _grid_ capacity, or some mixture? In Ireland there's now a _lot_ of curtailment, but it's mostly driven by inadequate grid capacity (wind power in particular expanded quicker than the grid could).