These transactions are scheduled directly between a generator and a load, that is, bilateral - between two parties. All bilateral bids offered within NY are also automatically scheduled by NYISO.   This is energy brought into New York from neighboring control areas, which include PJM Interconnection, ISO New England, Hydro Quebec and IMO (Ontario). The amount scheduled is determined by price, thus not all that is bid gets scheduled. Energy flowing out of New York to the neighboring control areas. Again price determines how much energy is actually scheduled for export. This is the sum of energy imports less exports. Wheel throughs have no impact on this calculation as their flow in and out nets to zero. The amount of energy purchased in one control area and delivered to another control area, that is, just wheeling through New York. All generating units in New York must submit bids in order to be considered by NYISO. Units are scheduled based on economics and the need to maintain reliable system operation.    
Balancing Market Advisory Summary
Date: 12/30/2001

Offered MWh Scheduled MWh Percent
Bilateral Bids 2018 2018

Generation Bids 557786 356365 63.9%

Imports 58240 57527 98.8%
Exports 7165 7048 98.4%

Net Imports/(Exports) 51075 50479 98.8%
Wheel Throughs 6000 6000 100.0%