Spatio-temporal analysis of possible wind generation output reductions for the Irish transmission system with a high penetration of renewables

This study outlines a modelling methodology utilised by EirGrid, the Irish Transmission System Operator, to apportion reductions in electricity output from wind powered generators because of a variety of security of supply issues and localised transmission congestion. A set of production cost simulations compiled to account for hypothetical dispatches on the Irish transmission system extending over the period 2011-2022 are reported using actual application data. Studies addressing security of supply set a limit for non-synchronous generation such as wind to be between 50 and 75% of the total system generation (demand plus exports) over the interval. The potential impact of the 75% maximum instantaneous wind penetration limit possible on the small, synchronous and relatively-isolated Irish transmission system by 2020 is assessed. Ireland is expected to achieve the majority of its 40% renewable target in electricity from wind and there will invariably be instances when the amount of wind generation will be greater than demand. This should also be seen in the context of transmission congestion where wind generation connects on a non-firm basis prior to completion of their deep assets. The description of the advanced and novel methodology used to determine these reductions is presented here.