This is probably of interest to no one but me, but I'm going to explain a little bit of what I picked up from CWLP's presentation last night about how they picked FPL. They received 16 offers from 8 companies, many of which came with several pricing options: fixed costs across the lifetime of the contract, escalating (where it goes up a certain percent each year), and staired (which I didn't catch the explanation of--perhaps it only escalates every few years?). CWLP staff knocked out 7 projects, then worked with The Energy Authority to analyze the remaining 25.
The Energy Authority is essentially a co-operative effort of municipal utilities to pool resources and purchase expertise in energy marketing that would be too costly and intensive to purchase alone. What it seems they specifically did here was provide a strong modelling background for rigourously comparing the 25 offers. This took the form of stochastic modelling, which means running your model with random (though probabilistic) combinations of your key variables. What emerges, I believe, is essentially a likelihood determine of outcomes.
It sounds like the key variables that they were considering was climate (i.e., wind availability) and energy prices, based on the location of each proposal, and compared on a time-of-day basis. This means, if I'm understanding correctly, that they weren't comparing, say, the average cost price of electricity and the average amount amount of electricity the wind turbines would produce. They matched when the electricity would be generated to the likely price of electricity at that time of day. (Both wind patterns and energy price patterns have long datasets to back this up.)
In the final analysis that they presented to the committee, CWLP offered a chart of yearly projected market prices compared with the contracted price per megawatt. Included in this chart were two primary variables: the capacity factor (i.e., what percentage of nameplate capacity will the turbines produce at?) and the energy inflation rate. Capacity factor was listed at 26.3%, which seems low. There wasn't any discussion of this number, so I don't know if this is their best estimate or something more conservative. The energy inflation rate was 3.5%. As mentioned last and in the SJR, recent history puts the energy inflation rate at something more like 9%. And the higher that inflation rate, the better the return to the city, and the lower our bills will be.