Physical. A 1 MW injection at the bus changes flow on the constrained element by SF MW. Positive worsens the constraint; negative provides counter-flow relief.

Price. SF is the share of the constraint's shadow price embedded in the bus's marginal congestion component. At SF = 0.30 against a $100/MWh shadow price, the bus picks up $30/MWh of congestion; at SF = −0.15 it receives a $15/MWh congestion benefit. Summed across all binding constraints, Σ(SF × Shadow Price) is the bus's total MCC - the congestion component of its LMP.

Note: shift factors shown here are derived, not published. They are estimated by regressing each PTID's LMP congestion component against historical binding-constraint shadow prices, and are intended as directional indicators of how each generator influences each facility.