What are some examples where the NYISO may update posted prices?
1. Reserve pick-ups. This was a problem fixed in 2000. SCD had been incorrectly calculating prices during reserve pick-ups. As a result, prices were reserved and subsequently changed. 2, Discrepancies between proxy bus and load bus prices. Zonal prices are a weighted average of generator prices in a given zone. At the start of the ISO, price changes that were made to generators did not properly carry over to changes in zonal prices. As a result, zonal prices had to be reserved and changed to reflect the zonal price changes. Technical Bulletin 28 gives more detail on how zonal prices are calculated 3. Missing SCD intervals The NYISO has a direct metering communication system with generators. One piece of this system in called the Performance Tracking System (aka PTS). SCD results are communicated to generators via PTS. Occasionally communication between SCD and PTS fails. As a result, prices don’t post for the bad intervals. Prices have to be posted after the fact from a storage databas
