LIM Data Warehouse - October 2006 -
Background
Data from various LIM vendors, most specifically North American ISO Electricity prices, is quoted 24 x 7 on an hourly or more frequent basis. As a result, during the transition each fall from U.S. Daylight Savings Time (DST) to Standard Time there are 25 hours in one day. LIM's data warehouse systematically captures values for the 25th hour and distributes the data. Prior to 2006, the "extra" hourly values show up as a correction in the MIM.2006 Treatment of DST
On October 29th, LIM will implement new functionality in response to client feedback, ensuring that price values for U.S. ISOs supplying a 25th hour every October are captured separately in the MIM (Note: from 2007 onwards, DST will extend until November). The data for the 25th hour will be captured in a new LIM column relation that will be added to each price symbol. The new column will therefore have data for one hour each year (or in the case of ERCOT, four 15 minute prices per year).LIM Data Vendors Impacted
The ISO data from Alberta (AESO), California (CAISO), ERCOT, NEPOOL, New York ISO and PJM will have the extra column added as follows:
Note: Values from MISO and Ontario (IMO) are not supplied because DST does not affect them.
Not Calculated for History
No back history of prior years will be available.Data Not Covered
The primary request from customers was for the addition of the 25th hour of price data for the ISOs. This change will be implemented as described on October 29, 2006. If there are requests to add non- price information to the coverage (e.g. load, ancillary, transmission etc.) then we will consider including these in the future.
