Transmission Equivalence Richard V. Kowalski Manager, Transmission Planning ISO New England

Transmission Equivalence © 2005 ISO New England Inc. 2 Power System Purpose The power system exists to serve load Generation to supply load Transmission to “move” generation to load (Load “limiting” to reduce power system needs) Need enough (per criteria) Generation and Transmission to reliably and efficiently serve load

Transmission Equivalence © 2005 ISO New England Inc. 3 Transmission System Functions Platform for generation functioning Delivery of: –Capacity –Energy –Competitive resources –Resource adequacy –Operating reserves –Fuel diversity –Load following (AGC) –Immediate contingency response Sudden generator outage Sudden transmission outage

Transmission Equivalence © 2005 ISO New England Inc. 4 Transmission System Features Loss reduction (reduction in capacity and energy) Voltage regulation; minimize voltage fluctuations Grid stabilization Bulk power system grid reinforcement Efficient use of existing regional resources Mitigate regional redundancy – reserves Facilitate equipment maintenance scheduling Availability/Longevity/Certainty “Fixed Price”

Transmission Equivalence © 2005 ISO New England Inc. 5 Resource Integration Size and Location are Important! Power system “balanced” by design – maintain acceptable loadings and voltages “Large” resources (relative to system strength) can upset the balance –Limit value of the resource Not a “minimally” interconnected resource May require significant transmission modifications to interconnect “Just Enough” generation generally isn’t enough