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: 06/27/2002

Offered MWh Scheduled MWh Percent
Bilateral Bids 5264 5264

Generation Bids 699734 512171 73.2%

Imports 60399 58598 97.0%
Exports 18312 17840 97.4%

Net Imports/(Exports) 42087 40758 96.8%
Wheel Throughs 6800 6701 98.5%