EMK:Water Values

Example Water Value Contour File

For detailed explanations of EMarket Water Values refer to The Water Values Technical Bulletins

EMarket has a facility for auto-calculating Water Values. If you have changed settings within a particular Run Definition you will need to use the Calculate Water Values Now Button on the Run Resource Window if you require fresh Water Values; alternatively you need to set the Auto Calc Water Values field to True.

More information on Water Values and how they are calculated can be found in: The Water Values Technical Bulletin

Water Value Contour Files

The Water Value file is named <Run Name>_WVMD.csv (<Run Name>_WV.csv for the older 2D water values) in the WVs sub-directory of the Data directory. When the Water Values are calculated using a Run Definition, the name given is the name of that Run Definition, e.g. if Water Values are provided for a Run Definition named "RunA" then the Water Value file created will be named "RunA_WVMD.csv".

The format of the file is as shown to the right (click to enlarge). The basic format is the standard comma separated value (csv) format. These files can be edited and viewed in Microsoft Excel, although caution should be taken that the files conform to the expected layout when editing is done. The file contains the Water Values for the Hydro Systems and Hydro Stations. Due to lack of space the entire format is not shown here. There is a single line header containing the date from which the water values are valid (always a monday), the number of weeks of water values in the file and the number of weeks for which these values are considered valid. The data for weeks beyond the valid weeks is not used by EMarket in runs and is mainly for verification purposes. The file header is followed by a section for each hydro system. Each of these sections is laid out as follows: The section has a header with the name of the system, it's nominal maximum storage in GWh, and a multiplier that is normally one but is greater than one for tributary systems. This multiplier is used to convert the stored energy available to the system to the amount of energy this storage can provide to the market as a whole. The next row contains a list of benchmark 'other storage' values, each representing a proportion of total storage in all other reservoirs against which the water values for this system are evaluated. The next row contains a list of figures representing the $/MWh values of each contour in the WV profile. This list could be different for each system, but currently it is always the same. Next there are M x N rows, where M is the number of 'other storage' values and N is the number of contours. Each row has W entries, where W is the number of weeks in the water value set. The rows are grouped by contour, with each group having M rows. The values are in GWh and represent the position of the contour line in storage volume.

Calculating Water Values

Example Water Value Profile

Water Values are calculated on the basis of an entire Run Definition and are dependent on nearly all of the parameters defined for a Run. A Run Definition must have a Water Value file associated with it.

To see which file is being used in the Run Definition click the Hydro Parameters Button in the Run Window and look in the Water Value Profile field.

EMarket can calculate Water Values at any time using a specific Run's resource files. To do this use the Calculate Water Value Now button in the Water Values Options Box in the special parameters area of Run window.

Alternatively, Water Values can also be automatically calculated at run time. This can be done by setting Auto Calc Water Values field to 'True' in the Water Values Options Box in the Run Window.

EMarket still supports the older method of calculation referred to as 2D water values (referring to the two dimensions of storage level and time which determine the value of water in the results). These water values are likely to be unused in the near future. The current method of calculation is referred to as Multi Dimensional or 'MD' for short. This refers to the extra dimension that effects these water values, being the total storage in other reservoirs and the possibility that more factors will be included in the calculation in the future.

The results of a Water Value calculation can be viewed graphically by double-clicking the Water Value Profile field in the Water Values Options Box in the Run Window. The Water Values Profile Window will be displayed showing individual Water Value contours. A Water Value contour relates storage levels to a particular Thermal Generator's Offer Price, and is used to determine which Offers Hydro Generators will make.

The left area of the window shows a plot of the Water Value contours in the current Water Value profile. The box to the right of the window shows the value of each Water Value contour. The contours shown in this box can be clicked on to select them, this will highlight the selected contour in the graph. Click on the name tabs at the top of the window to show the contours for a different Hydro System or station.

The title of this form is Water Value Profile - <Water Value profile name>. Often the Run Definition name and the Water Value profile name will be the same.

Note: Water Value Calculations will only use consecutive inflow years for which data is available for all inflows. For example, if inflow data from 1969-1979 is being used for a run and data is missing for 1978, the Water Value calculations will be based on the data from 1969-1977, as these are the consecutive years from 1969 for which data is available.

Editing Water Value Files

Warning: Every time a Run is executed, the Water Values will use values for the generic generators that are named in the Water Value Profile window.

At some stage you may want to use Water Value contours containing generic Generator Offer values that do not correlate with the generic Generator Offers in your Run Definition. In this situation it is necessary to give the contour another name. For example, if you want the third contour value to be $20/MWh instead of $30/MWh, you would have to give the contour a name that doesn't correspond to any Generators in your Connections Resource. To do this, open and edit the appropriate Water Value contour file from your data set in Excel.

Change the value of the contour and rename it.

To avoid confusion, you should now save this file with a different but easily recognisable name. Once you have linked the new Water Value contour file to your Run Definition you can view it directly from the model.

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