Methodology
The SpOT (Spectron OTC) Window UK power indices are calculated from the volume-weighted average of all Day-ahead/Month-ahead Baseload or Peaks transactions executed during a specific time window through Spectron's electronic trading platform. All times are British Standard Time (BST), as determined by Spectron’s in-house atomic clock.
Day-ahead Indices
The Day-ahead Baseload indices are calculated using the volume-weighted average of trades executed between 08:00-09:00 BST and 08:00-12:00 BST through Spectron, for Baseload delivery on the next weekday (whether it is a working day or not) following the deal date. (E.g. the index published for 15 March 2006 was for all the Baseload trades executed within the time window on 15 March 2006 for delivery on 16 March 2006). On Friday a Monday index is published as well as a weekend index, for trades executed for Saturday and Sunday as a combined strip (individual Saturday or Sunday deals are not included).
The Day-ahead Peaks index is calculated using the volume-weighted average of trades executed between 08:00-12:00 BST through Spectron, for peak-time delivery on the next weekday (whether it is a working day or not) following the deal date. On Friday a Monday index is published.
Month-ahead Indices
The Month-ahead index is calculated using the volume-weighted average of all Month-ahead trades executed between 08:00-12:00 through Spectron, on its internet broking platform. The Month-ahead index values power for delivery in the EFA month following the EFA month in which the deal is executed. The index month is the delivery month and the index date is the deal date e.g. the index for the 16 November 2006 is for all trades executed up to 6 pm on that day for power being delivered every day in the EFA month of December.
Weekend-ahead indices and Bank Holidays
In the case of bank holidays, indices are published for the individual days within the bank holiday and the day after the holiday, using trades executed on the last working day before the break began. So in the case of a bank holiday on the Monday, indices are published for the Weekend, the Monday and the Tuesday.
Easter and Christmas: For Easter, there is also a Friday index, with all indices calculated from deals done on the Thursday preceding the holiday. For Christmas and New Year indices are also published using deals done on the preceding working day. There are no Month-ahead indices published on weekends or bank holidays.
Contingent Methodologies
Should the number of trades executed in the window be:
Five or greater - the index will be calculated using a weighted average of those trades.
Between one and four - the index will continue to be calculated using a weighted average of those trades. However, it will be noted on the index page that the calculation has been based on less than five trades.
Zero - the index shall be calculated using all trades executed so far that day. (In the exceptional case when there is no trade so far that day, then the index value will default to the All-day index value published at the end of the day.)
Index out-turns
Monthly index out-turn values, calculated from the average index value over the course of a month, will be published for both Day-ahead and Month-ahead indices, as these are commonly used for contract benchmarking.
Amendments
Should there be subsequent changes to the source data used to calculate the indices, then the index shall be recalculated and republished automatically i.e. the index shown within the historical indices tool is the most up to date calculation of the index.
Any amendments from the originally published indices will be highlighted and published on the Amended Indices page.