On January 8th, 2006, I posted the following message under the article Playing with Fire – Part II:
Generating facilities are dispatched on their variable costs, not on average costs. Hydro facilities variable costs are nearly zero and those units are usually energy limited, but their new development costs are usually very high. In the US, old hydro developments expected benefits are already committed. The LMP price is relative to variable costs. Bidding systems of Model 2 are suspect, as they are in your proposal.
In order to make sense of the data it is not possible to do simply arithmetic calculations as you propose. It is necessary to simulate what the expected random LMP values are for a long over a long period of time. That depends on the probabilities of rainfall or the snow that is expected to fall and melt into the hydro plant. In addition, the power flows at a given node depend on the system as a whole at every moment.
If a region does not allow central or distributed generation, energy efficiency, and transmission development, they should know they will be playing with fire, not matter what the model is.