The formulation of a Poolco model suitable for power system planning i
s presented. The model involves only slight enhancement to existing co
nventional power system software and directly enables the calculation
of spot prices and a bid-based dispatch, Included is a method for deco
mposing spot prices to reveal components caused by system congestion,
An example illustrates how financial hedges that are traded in the Poo
lco scenario will affect system planning decisions.