Input Data
The input data types processed by EMarketOffer:
- Generation Data
- Price data
- Offers data
- Demand data
- Transmission data
- Static (user-defined) data
Generation Data
Generation data is used:
- As information-only in theUnits Information Grid for the Market Data Source
- To calculate Powerflows for the Market Data Source
- To calculate Powerflows for the Powerflow Case Data Source
Loading Generation Data
Historical Generation data can be loaded from an online database (see Connecting to a Networked Database). Historical or user-created Generation data can be loaded into Powerflow Case Definitions from file as a generation profile.
Price Data
Historical Price data is used as information-only in the Units Information Grid for the Market Data Source
Loading Historical Price Data
Historical Price data can only be loaded into EMarketOffer through direct connection to an online database (see Connecting to a Networked Database).
Offers Data
Historical Offers data is used:
- As information-only in the Units Information Grid for the Market Data Source
- As input into the seven-day Offers Profile in forecast Definitions
- As input into Scenario Data Sources based on historical Trading Periods (when available)
NOTE: EMarketOffer does NOT use Offers to calculate Powerflows for historical Trading Periods.
Loading Historical Offers Data
Historical Offers can be loaded either through:
- direct connection to an online database
- from pre-formatted Offers files
- Offers profile files (Forecast Definitions only)
Pre-formatted Offers files must use the same formatting used by the COMIT service for providing Offers data and be named in the following manner:
- Offersyyyymmdd.csv
Where:
- 'Offers' is the text 'Offers'
- 'yyyy' is the numerical 4 digit year (e.g. 2012)
- 'mm' is the numerical 2 digit month (e.g. 06)
- 'dd' is the numerical 2 digit day (e.g. 08)
You can download Offers files directly from COMIT and use them without further editing (once renamed).
NOTE: Date format is important - the date in the file name is used to allocate offers data to specific week days. One Offers files cannot contain data for periods from two different calendar days.
Offers files are processed row by row without regard to overall integrity. This allows you to edit the raw Offers files prior to loading to:
- Alter Offer Prices and Quantities
- Restrict the number of offered periods to less than a full day
- Restrict the number of offering Generation Units to less than those actually offering on the day
The formatting for the Offers files can be found in Offers File Format.
Offers profile files can also be used. An Offers profile file uses a proprietary format designed to capture a complete seven-day profile suitable for importing into a Forecast Definition. The format of this file can be found in Offers Profile File Format.
Using Offers with Forecast Definitions
EMarketOffer's Forecast Definitions are based on a weekly Offers Profile, organised by day of week (as opposed to date). Offers for no more than seven consecutive days can be loaded into a Forecast Definition.
The following points should be noted:
- Where a Forecast Effective Date Range extends beyond seven days, Offers from the loaded profile will be re-used (by corresponding day of the week) from day eight onward
- Where Offers for fewer than seven days are loaded into a Forecast Definition , any periods in the Effective Date Range not covered by the loaded Offers will fail to dispatch
- New Offers can be loaded over the top of existing Offers. examples of how this might be useful include:
- producing modified historical offers by loading a week profile from the database and then loading an edited and/or partial Offers file containing different data
- Modifying a single generator's offering behaviour by loading an edited file containing Offers for only the Generation Unit and specific Trading Periods of interest leaving all previously loaded Offers (for this or any other generator) unchanged.
- Offers files are loaded consecutively by date from earliest to latest. Loading more than seven-days of Offers data from file will cause over-writing of the weekly Offer profile. for example if ten days of offers are loaded from file the first three days will be lost.
Demand Data
Historical Demand data is used:
- As input into calculating the Powerflows in the Market Data Source
- As input into the seven-day Demand profile for Forecast Definitions and Powerflow Cases
Which Demand data to use with EMarketOffer?
For best results EMarketOffer's database connection should be configured to use reconciled SPD Daily Demand data (available to subscribed COMIT users) as this most closely matches the historical Offers used in final dispatch. However, EMarketOffer can be configured to work with SCADA or other Demand data. Where SCADA data is used the net final Load at each Market Node should also be used.
Loading Historical Demand Data
Historical Demand can be loaded into EMarketOffer either through:
- direct connection to an online database,
- from pre-formatted Demand files
- from demand profile files
Pre-formatted files
Pre-formatted Demand files must comply with EMarketOffer's Demand file format (see Demand File Format) and named in the following manner:
- Loadyyyymmdd.csv
Where:
- 'Load' is the text 'Load'
- 'yyyy' is the numerical 4 digit year (e.g. 2012)
- 'mm' is the numerical 2 digit month (e.g. 06)
- 'dd' is the numerical 2 digit day (e.g. 08)
NOTE: The date format is important. EMarketOffer uses the date in the file name to allocate the Demand data to specific days. One demand file cannot contain data for periods from more than one calendar day.
EMarketOffer processes the Demand files row by row and does not check overall integrity. This allows you to edit the raw files prior to loading into EMarketOffer to:
- Alter Demand Quantities
- Restrict the number of Demand periods to less than a full day
- Restrict the number of Demand Nodes to less than those actually drawing down power on the day
The formatting for the Demand files can be found in Demand File Formats.
Demand Profile Files
A Demand profile file uses a proprietary format designed to capture a complete seven-day profile suitable for importing into a Forecast Definition or Powerflow Case. The format of this file can be found in Demand Profile File Formats.
Using Demand with Forecast Definitions and Powerflow Cases
EMarketOffer's Forecast and Powerflow Case Definitions are based on a weekly Demand profile, by day of week. Demand figures for no more than seven consecutive days can be loaded into a Definition.
The following points should be noted:
- Where a Forecast or Powerflow Case Effective Date Range extends beyond seven days EMarketOffer will re-use the loaded Demand by day of the week from the profile for all weeks in the Effective Date Range.
- Where Demand for fewer than seven days is loaded into a Definition, any periods in the Effective Date Range not covered by the loaded Demand will fail to dispatch
- New Demand data can be loaded over the top of existing data. For example it is possible to load a full week profile from the database and then load a partial Demand file that has been edited to contain Demand for a single Node for a specific number of periods on a specific day. In this case only those periods for the selected Node will be overwritten with new data, all other Demand figures will remain unchanged.
- Demand files are loaded consecutively by date from earliest to latest. Loading more than seven days of data from file will cause over-writing of the weekly Demand profile. For example if ten days of Demand figures are loaded from file the first three days will be lost.
- When loading Demand data from database it is possible to specify a date range covering several weeks of Demand data. In this case an averaged Demand profile is created by day-of-the-week and Trading Period. It is not possible to create averaged Demand profiles by loading from file.
Transmission System Data
EMarketOffer can create a set of grid data (circuit details, line re-ratings and constraints) at run time from one of four sources:
- Historical transmission system data files provided by Energy Link
- Transmission system files sourced through the EM6 web site operated by Transpower division EMS
- In-house databases
- The files available each business day from the Energy Link web site (for grids from 16-Jul-09 onward)
Of the sources above, 1 - 3 are legacy data sources and we have stopped supporting them as the data available from EM6 is incomplete for the purposes required in EMarketOffer, and because we have gone to great effort to provide daily grid and reserves files that include all data reuired to solve the market by half hour. Only the daily updated grid files from 16-Jul-09 are now supported (though the other types of existing grid data can still be used in the meantime). The daily updated files also include full reserves data.
On startup EMarketOffer checks the Energy Link web site for the new grid and reserves data and automatically downloads files if you are not up to date.
The Connect Grid Data Tables check box in the Database Connection Settings window can be checked if you wish to use grid data from your own database, subject to the following:
WARNING! EMarketOffer will ignore any database links for grid data if grid data can be obtained from files. To use grid data from your own database you must delete any grid data files that are downloaded by EMarketOffer on startup.
DISCLAIMER: Energy Link takes a great deal of care in extracting grid and reserves data from the SPD daily final pricing case data files provided on the Electricity Authority's web site. However, we are totally unsupported in this endeavour and cannot in anyway guarantee the accuracy of the data we provide to EMarketOffer users. We provide the data in good faith and will not be held liable for the use of the data in EMarketOffer or in any other application, for the accuracy of the data, or for any special or consequential damages or losses resulting in any way whatsoever from the use of the data.
The following descriptions of grid data relate only to the data which is updated on Energy Link's web site each business day. For assistance with earlier versions of grid data (for all periods up to and including 15-Jul-09) you need to contact Energy Link or refer to an earlier EmarketOffer User Manual.
The SPD daily final pricing case data files are parsed by Energy Link each bussiness day to extract grid and reserves data. Grid data is stored in files with names:
- BaseGrid_yyyymmdd_yyyymmdd.csv contain the base data for circuits, transformers and other key grid elements by half hour
- Equations_yyyymmdd_yyyymmdd.csv contain the equation constraints by half hour
- Reratings_yyyymmdd_yyyymmdd.csv contain circuit and transformer outages and reratings by half hour
In each case, the two dates show the range of dates covered by each file (from date first, to date second). The files are added to day by day but do not contain more than one year of data each.
In the same folder as the files above, you will also find VLRs_yyyymmdd_yyyymmdd.csv files which contain the VLR ratings for a small number of circuits which are currently being trialled: this data comes from Transpower's web site and are checked periodically.
Static (User-Defined) Data
EMarketOffer uses static data to calculate or organise the dynamic data produced by the Run (see the Circuit Item example below). Static data tends to remain unchanged between the Trading Periods contained in a Run,
| Item | Description | Static Data | Dynamic Data |
|---|---|---|---|
| Circuit |
|
|
|
Modelled Items are defined by static data. Some Items are global, i.e. common for all Definitions, and their associated static data must be pre-defined (e.g. Companies and Regions) Most Modelled Items, and their static data, are created for each new Definition (e.g. Generators or Nodes).
NOTE: To avoid time-consuming effort re-creating data in Definitions, Modelled Items, with their static data descriptions, can be imported into a Definition using EMarketOffer's, data loading functions, once loaded these Items can be modified, added to or removed with the Definition editor.
Functionality to maintain global static data can be accessed through the Edit Menu in the Main Window.
Static data in Definitions can be accessed through the Forecast Definition Window or the Powerflow Case Definition Window.