"Palazzo, William" <William.Palazzo@nypa.gov> writes to the 
NYISO_TECH_EXCHANGE Discussion List:

In response to some E-mails on the subject report we offer the following
comments.  We believe expressing the locational requirement as a function of
the capability period peak sends a better price signal to LSE's.  Some LSE
loads will have larger peak in summer and others may be balanced or even
peak in the winter.  Seasonal ICAP would facilitate capacity exchanges
between summer and winter peaking areas.

As a practical matter the requirement can be expressed any way.   For this
exercise we just left it as a percentage of the summer peak because it
provides a reference point to the current requirement and illustrates an
order of magnitude of the potential reduction in the winter requirement that
may be justified through an examination of the seasonal risk.   We agree
completely that all issues, including deficiency charges, modeling, etc.,
must be considered in any methodological change.  There was no intent to
suggest everything else would remain unchanged.