An operational capacity credit might be closely related to the short-term accuracy of the wind forecast that is used to schedule generation schedules for the following day. This issue is treated in more detail in Milligan et al. Also, ELCC measures depend on the way wind is modeled in the production cost and reliability models. This brings us to the question of how to calculate an operational intermittency penalty for a wind plant. In my judgment, this is an ill-formed question, because it is unclear on what basis the penalty should be assessed.
Conventional generation can include many different types of resources with differing availabilities.
Furthermore, such a penalty, should we accept it, would be subject to the relative value of an additional kW, which varies throughout the day. During peak load periods, most existing capacity is pressed into service. In scheduling generators during system peaks, mistakes are much more costly than in off-peak periods. One would rely on wind plants during the peak period to the extent that wind plant output forecasts are believed to be accurate and result in significant output. The value of both capacity and energy varies widely and depends on the interplay between system loads and available generation.