What was unusual was the fact that it surpassed the demand on Ireland’s electricity grid throughout the entire island for the first time.
That meant that some of the energy was exported to Britain and Ireland had to meet the rest of the demand using fossil fuels.
That confused me in this summary. Looking at the actual article makes sense of that nonsense:
Currently, the country’s electricity grid is only permitted to have a maximum of 75 per cent renewables in its energy mix. That meant that some of the energy was exported to Britain and Ireland had to meet the rest of the demand using fossil fuels.
Maybe the same issue as here in Germany, there are basically not the capacity in the electricity grid to being all this energy to the consumer..
In Germany the issue is, to bring the energy from the northern down to the south (direction to the alps), because there is basically no electricity line existing 😅
Inflexibility of conventional power plants is one issue, but for Ireland things have developed to a point I suspect it is no longer the main operational constraint on the grid.
Ireland is an island grid and needs to keep system inertia on its own (HVDC connection with neighbors cannot synchronize Ireland's grid with UK's, let alone continental Europe). This service is traditionally provided by conventional power plants in GW scale grids, but soon when synchronous condenser and inverter-based solutions become norm, there is no reason why 100% instantaneous wind + solar is not possible as shown already in various microgrids.
Similar develop can be observed in other islanded or nearly islanded GW scale grids such as South Australia.