  Concerns about system adequacy have led to the establishment of capacity
mechanisms in a number of regulatory areas. Against this background, it is
essential to accurately quantify the contribution to security of supply that
results from interconnectors to neighbouring systems. This paper introduces a
definition of capacity value for interconnection between two systems in the
form of a capacity allocation curve. Four power flow policies are proposed to
encompass the full range of possible market outcomes that may affect the
capacity value. A convolution-based method is presented to efficiently compute
and compare capacity allocation curves, and it is applied to a model system
that is inspired by Great Britain's interconnection with the continental
Europe. The results indicate areas of interest for the coordination of capacity
mechanisms.
