Before starting the analysis, data must be collected, organized and understood in each of their entries. Raw data can be downloaded from GME website [32] following the path: GME website>Esiti dei mercati e statistiche>offerte pubbliche>MSD ex-ante or MB. Data include a large amount of information about all of the offers submitted by the operators for every hour and for every product. Therefore, the download is only available one day at a time.
With an express script, to be written on the Console of Google Chrome, the automation of the process is possible. After that, 365 .xml files per year (2018 and 2019) must be organized in readable way. The main issues are the high number of files and their total dimension. To simplify the analysis, 2018 and 2019 are treated separately. Is created an original C#
program, that takes input files, elaborates them and gives output files. Daily files are used as
MARKET DATA ANALYSIS CHAPTER 3
inputs32, while the program scrolls through files and creates different outputs for every market zone. The process is iterated, obtaining as a result quarterly files for every market zone excluded NORD, whose results are monthly. This distinction is necessary to allow MATLAB managing data with no issues. No information is lost in the process and at this point data are simpler to use. Then, .xml files are opened with Excel, for an easier access and to understand the logic of GME’s data publishing. Some Excel columns are deleted since not necessary for this work. For each market zone, Excel files contains the following discussed entries.
• PURPOSE_CD: indicates the purpose of the offer and can either be ‘BID’ for downward offers or ‘OFF’ for upward offers.
• TYPE_CD: can be REG for current offers or STND for standard ones.
• STATUS_CD: is the state of the bid after market conclusion. ACC means that the offer is accepted and thus remunerated, REJ stands for rejected. If the offer does not respect regulation requisites, it is marked as unsuitable, INC, while if it is replaced by a new one, the label is REP. SUB stands for submitted and indicates that the offer is reserved on MSD for MB.
• PARTIAL_QTY_ACCEPTED_IN: it indicates whether or not, Y or N, the accepted quantity is lower than the offered one.
• OPERATORE: is the operator submitting the offer, e.g. ENEL PRODUZIONE SpA, ENGIE ITALIA SpA, etc.
• UNIT_REFERENCE_NO: identifies the UP through which the operator is submitting the offer.
• GRID_SUPPLY_POINT_NO: it is the relevant grid exchange point (PSR_). Generally, it is a set of primary cabins, belonging to the same market zone but not necessarily close to each other, within which it is indifferent where the injection (withdrawal) actually takes place, for dispatching optimization [33].
• INTERVAL_NO: it specifies the relevant period of the day and goes from 1, that indicates the hour between 12 am and 1 am, to 24 that indicates the hour between 11 pm and 12 am.
• BID_OFFER_DT: it is the date of the offer.
• SCOPE: it indicates the product the operator is bidding for, which are: i. RS, Secondary Reserve, ii. GR1, GR2, GR3, (GR4 only for MB) three (four) parts in which the operator can split its reserve band to supply Tertiary Reserve, Congestion
32 The choice to use the C# one month at a time and, after that creating a trimestral file, is due to the RAM amount used by the program.
To run the script for a month, 2 GB of free RAM are required. For completeness, NORD files must be processed month by month because of the big amount of total offers present.
Management and real-time balancing services, iii. ACC, is the fee required for Start-Up, iv. CA, is the fee required for Setup-Change, v. AS, indicates the Minimum offer.
• QUANTITY_NO: it is the quantity in MW (for one hour), as submitted in the offer by the operator or the quantity contained in the STND offer.
• ADJ_QUANTITY_NO: it is the quantity in MW (for one hour), as adjusted by Terna following the process described in 1.5.3.3.
• AWARDER_QUANTITY_NO: is the quantity in MW (for one hour), as eventually awarded by the market.
• ENERGY_PRICE_NO: it is the price in €/MWh, as submitted in the offer by the operator or contained in the STND offer.
• ADJ_ENERGY_PRICE_NO: it is the price in €/MWh, as adjusted by Terna, to respect offer constraints (e.g. UVAM upward cap as in 2.3.1.1).
• AWARDED_ENERGY_PRICE_NO: it is the price in €/MWh, as eventually awarded by the market and paid as bid.
About GR-offers, is important noticing that the quantity offered in GR2 incorporates the one offered in GR1, and so on, with an equal or higher (lower) price for upward (downward) offers, as shown in Figure 3.3. The operator is allowed to split its available capacity as it prefers, with no need to exactly divide it in three (four on MB) equal parts. In many cases, including the case study presented in Chapter 4, due the limited trading capacity, only the GR1 offer is presented.
A few contingencies lead to think that the offer submission process is still widely manual.
This can be often seen in offers presented with quantity equal to zero. Those quantities are afterwards adjusted by Terna, to the minimum mandatory quantity33 or to the STND offer.
Terna’s adjustment process appears instead as automatic and not related to grid needs, the adjustment is implemented, for current offers with quantities that do not respect bidding constraints, even if the offer is rejected or only partially accepted at the end of the market.
Adjustment process interests less frequently offers’ prices and it is limited to prices exceeding regulation limits. The example comes from the UVAM pilot projects; sometimes UVAM BRPs offer at a high price that can even reach VoLL34, trying not to be selected but still benefitting of the incentive. However, during mandatory hours (from 2 to 8 pm) Terna adjusts the price to the mandatory upper limit of 400 €/MWh -still far from market prices- for upward offers. This behavior caused the reduction of overall relevance of the results of pilot projects, since UVAM are rarely selected.
33 According to technical requisite as described in 1.5
34 i.e. Value of Lost Load, equal to 3000 €/MWh. It is the cap for market offers and expresses TSO’s evaluation of 1 MWh not supplied.
MARKET DATA ANALYSIS CHAPTER 3
The missing link between the specific of UPs and related PSR is clear for UVAMs. All of the UVAM offers for a certain market zone refer to the same PSR, still providing anyway a simplifying information for the analysis of UVAM trends. UVAM PSR zone by zone are: in NORD the PSR_295, in CNOR the PSR_297, in CSUD the PSR_299, in SUD the PSR_301, in SICI the PSR_314 and in SARD the PSR_305.
Figure 3.2 Splitting logic for upward offers. For downward offers the order of the arrows is inverted.