In a small electricity grid such as the all Ireland system of Northern Ireland and the Republic of Ireland, managing with the variability of high levels of wind power generation will be crucial to ensuring the economic success of wind energy generation and the overall stability of the electricity system. Storage and interconnection are frequently proposed to manage this variability and total flexibility of the interconnector is assumed. This paper examines how market and meteorological effects could constrain interconnector operation. Currently an interconnector between the Republic of Ireland and Wales officially referred to as the East West Interconnector is in planning. The split between energy transfer and reserve provision through the interconnector will be dictated by energy prices and relative value of reserve services. The levels of wind power generation in each connected region may limit the mutual support expected from interconnection. In this regard wind forecasting and wind correlations in the connected regions are extremely relevant and are discussed in this paper.