Documentation about calculation methods used for the electricity supply price index (SPIN 35.1),

Transcription

1 STATISTICS SWEDEN Documentaton (6) ES/PR-S 0-- artn Kullendorff arcus rdén Documentaton about calculaton methods used for the electrct suppl prce ndex (SPIN 35.), home sales (HPI) The ndex fgure for electrct (SPIN 35.), home sales, shall reflect the prce developments for the fnal consumer or fnal user as measured n Swedsh crowns. These consst of Household Consumers and Others. The consumer prce ndex for electrct (excludng grd fees) wth taxes removed s used for Household Consumers. A model bult on prce nformaton from the Nordc electrct exchange Nord Pool s used for Others. The model for Others s composed of four sub-ndexes, whch are totalled b ther ndvdual consumpton values. These four parts are spot prces, a one-ear contract that follows the calendar ear, a one-ear contract delver begns at a tme other than Januar, and a two-ear contract that follows the calendar ear. Dscusson wth power supplers and the avalablt of meter data form the bass of the son to dvde measurements nto these contracts. The two ear contract s ntended to represent all contracts wth a perod longer than months. urthermore, the ndex fgure for Household Consumers and Others s totalled b the same prncple. The ndex fgure for grds (SPIN 35.3) s based upon prce measurements from local grds. The same ndex fgure s used for both consumer categores. Prce data s collected from approxmatel 50 grd areas. The ndex fgure for electrct suppl (SPIN 35.) s a total of the ndex for electrct (SPIN 35.) at the ndex for the grd (SPIN 35.3). The model electrct prces for the Others categor, as measured through Nord Pool, has been mplemented for ndex fgures as of Januar 00. The model was expanded upon n Januar 006 to also nclude contracts wth perods longer than one ear. or earler perods (before 00) prce nformaton from power producers has been used. Below the subcomponents ncluded n the calculatons are descrbed n greater detal. Calculatng an ndex for spot prces As of November 0 Sweden was dvded nto four bddng areas, prces dffer between areas. Ths also means that the calculaton of the ndex for spot prces has been changed from November 0. The monthl spot prces, n SEK/Wh, per bddng area are retreved from Nord Pool Spots webste each month. Those prces are weghted together Producer prce ndex for Electrct suppl

2 STATISTICS SWEDEN Documentaton (6) ES/PR-S 0-- artn Kullendorff arcus rdén nto an average spot prce for the whole of Sweden, after shares of sold volumes at spot prces for each bddng area, n ths wa: If s the weghted average of the monthl spot prces a gven month m n the ear, the ndex lnks for the spot prce ndex, December = 00, can be wrtten as:, m I, Dec 00 P, m P, Dec Calculatng an ndex for a calendar ear contract odel for one ear contract The ndex s ntended to show the change over tme for those prces pad for electrct delvered durng a gven month the electrct prce s fxed n a fxed prce contract for the calendar ear. The fxed prce s that whch apples for the delver perod and was ded upon b an earler agreement. The average prce 3 over all contracts regardng the delver perod of Januar up to and ncludng December n the ear can be wrtten as (=orward): Pm, w, ; w, ; jan jan Where jan w w s a weghted dstrbuton based on how large the, jan, contracts' percentages are concluded ever month for the two ears precedng the begnnng of delver. Addtons to the prce n a gven month also occur accordng to a standardsed schematc margn and the electrct certfcate fee. The electrct certfcate fee s collected from the Swedsh power grds' market statstcs. The prces used are the average monthl prces multpled b the percentage of those oblgated b a purchasng quota n the Others categor. 3 Addtons to the prce n a gven month also occur accordng to a standardsed schematc margn and the electrct certfcate fee. See footnote. Producer prce ndex for Electrct suppl

3 STATISTICS SWEDEN Documentaton 3(6) ES/PR-S 0-- artn Kullendorff arcus rdén n / n,, ) ( n, - s the number of busness das a month n the ear -. n / n,, ) ( n, - s the number of busness das a month n the ear -. Thus P n n / n / n m, w, (, ) w, (, ) jan jan Ths apples for all months m n the ear, whch s perfectl natural as the prce s supposed to reflect a fxed prce contract that follows the calendar ear. odel for two ear contract The ndex s ntended to show the change over tme for those prces for electrct delvered durng a gven month the electrct prce s fxed n a fxed prce contract wth a two-ear perod The fxed prce s that whch apples for the delver perod and was ded upon b an earler agreement. Average prce 4 over all contracts regardng the delver perod of Januar up to and ncludng December n the ear can be wrtten as ( = orward ear ):, jan, w 3 ;, jan, w 3 ; and 4 Addtons to the prce n a gven month also occur accordng to a standardsed schematc margn and the electrct certfcate fee. See footnote. Producer prce ndex for Electrct suppl

4 STATISTICS SWEDEN Documentaton 4(6) ES/PR-S 0-- artn Kullendorff arcus rdén, jan, w ;, jan, w ; and there, jan, w and w s a weghted dstrbuton based on how large, jan, 3 the contracts' percentages are concluded ever month for the two ears precedng the begnnng of delver. and n / n,, ) ( n, s the number of busness das a month n the ear. Ths apples for all months m durng the ear, whch s perfectl naturall as the prce s supposed to reflect the average of two fxed prce contracts that each follow two calendar ears. Producer prce ndex for Electrct suppl

5 STATISTICS SWEDEN Documentaton 5(6) ES/PR-S 0-- artn Kullendorff arcus rdén Calculatng an ndex for a "rollng" contract perod Ths part of the model s ntended to measure the part of the fxed-prce contract that does not necessarl follow the calendar ear. The ndex s ntended to show the change over tme for those prces that are pad for electrct delvered durng a gven month. Delveres for a rollng month contract occur at a fxed prce over the course of months. The fxed prce s that whch apples for the delver perod and was ded upon b an earler agreement. The average prce for all contracts regardng the delver perod of the month m to month m+ can be wrtten as m m P w P, () w m m; m m w s a weght dstrbuton based on how large the contracts' percentages are and ever month for the ear precedng the begnnng of delver. In the case of "rollng" contracts, one does not consder that certan contracts can be concluded for more than one ear precedng the begnnng of delver P s the delver perod's geometrc average prce for a gven prce m; determnaton month : m; m P () ; ; s the average prce month for delveres n the gven month μ. ; s meanwhle not known because short-term trade (4 week blocks) starts so ver close to the begnnng of the delver perod. Thus, t s assumed that the average prce durng the prce determnaton month s the same for all those months ncluded durng each delver season., Jan; eb; ar; Q; (3.) Apr; aj; Jun; Q;, (3.) Jul ; Aug; Sep; Q3;, (3.3) Okt ; Nov; Dec ; Q4;, (3.4), Q ; To Q4;, s the geometrc mean fgure of the closng prces and busness da h=}},, H\\ durng the prce determnaton month n quarterl terms ENOQ- to ENOQ4- (=delver ear). Producer prce ndex for Electrct suppl

6 STATISTICS SWEDEN Documentaton 6(6) ES/PR-S 0-- artn Kullendorff arcus rdén or quarter or ever prce determnaton month there s, wth the smplfcaton made n (3.), (3.), (3.3), and (3.4), average prces for four delver perods accordng to () that are ncluded n the calculaton of the ndex. A prce apples for the delver from Januar to December, one for the perod Aprl through arch, one for the perod Jul to June, and one for the perod October to September. B replacng () wth (3.) n () the fnal prce can be calculated as an unweghted, average prce regardng four ndvdual, fctve contracts wth months delver perod (Januar to December, Aprl to arch, Jul to June, and October to September). The gven monthl prce s thus the average of the four earl contracts that refers to delver durng the gven month. (4) Producer prce ndex for Electrct suppl