Antares Xpansion
Investment simulations for Antares studies
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Once the Antares study has been prepared for the Antares-Xpansion simulation, by the introduction of virtual nodes as described in Prepare the Antares study, the user must use the candidates.ini
file to characterize the investment candidates.
candidates.ini
Not all links in the Antares study are by default investment candidates. The candidates are defined in the candidates.ini
file, which must be located inside the user/expansion/
directory of the Antares study folder: antares-study-folder/user/expansion/candidates.ini
.
candidates.ini
fileEach investment candidate is characterized by the following properties:
The format is a standard .ini
and should follow this template:
In Antares-Xpansion, the investment decisions only affect the capacity of the Antares' links. Investment in physical generation capacity is done with virtual nodes as described in Prepare the Antares study.
name
String, mandatory. Specifies the name of the investment candidates. Antares-Xpansion uses this name in the output and the logs.
:warning: This field must not contain spaces!
link
String, mandatory. Defines the link of the Antares study candidate for investment, whose capacities (direct and indirect) will be modified by Antares-Xpansion. The syntax of the link name includes the names of the two Antares nodes that are connected by the link, separated by "-", for example:
Node names that include spaces or dashes are not compatible with Antares-Xpansion. The origin area corresponds to the first in the spelling order. The same link may contain several investment candidates (see this section).
annual-cost-per-mw
Float, mandatory. The decimal separator is the point. It defines the fixed cost annuity of the investment candidate (in €/MW/year). Depending on the type of candidate, the fixed cost annuity can include:
max-investment
Float. Represents the candidate's potential, i.e. the maximum capacity (in MW) that can be invested in this candidate. If this parameter is set, the invested capacity can take any value in the interval \( [0, \texttt{max-investment}]\).
unit-size
Float. Defines the nominal capacity (in MW) of the investment candidate's units.
max-units
Integer. Corresponds to the candidate's potential in terms of number of installable units. If the parameters max-units
and unit-size
are set, then the invested capacity is necessarily a multiple of unit-size
from the set:
$$ \{0, \texttt{unit-size}, 2 \cdot \texttt{unit-size}, … , \texttt{max-units} \cdot \texttt{unit-size}\}. $$
!!! Warning The definition of an investment candidate must necessarily include either (i) a maximum potential in MW (max-investment
) or (ii) a unit size in MW (unit-size
) and a maximum potential in number of units (max-units
).
already-installed-capacity
Float. Corresponds to a capacity that is already installed on the investment candidate's link. If Antares-Xpansion finds that the investment in this candidate is economically relevant, the new capacity will be added to the already installed capacity. The transmission capacities initially indicated in the Antares study are not considered in the already-installed-capacity
parameter and are overwritten by Antares-Xpansion.
[in]direct-link-profile
String, specifying the name of a file. This file must be located in the user/expansion/capa/
directory of the Antares study. It must contain at least one column of 8760 numerical values (the decimal separator is the point), see Figure 5. Multiple columns are used in order to use different data depending on the Monte-Carlo year in process, see details here. When only one column is specified, the same profile is used by Antares-Xpansion for all Monte-Carlo years of the Antares study and all assessed capacities.
!!! Remark Both files direct-link-profile
and indirect-link-profile
must contain the same number of columns.
The [in]direct-link-profile
makes the link between the invested capacity and the capacity that is actually available, in the [in]direct directions of the Antares link, for the 8760 hours of the year. More details are given in this section.
The [in]direct-link-profile
can be used for example to represent the maintenance of a generation asset via a seasonalized power outage, or the average load factor of intermittent renewable generation, defined at hourly intervals.
File user/expansion/candidates.ini
:
File user/expansion/capa/capa_pv.csv
:
Figure 5 – Example of a file containing a load factor profile in the Antares-Xpansion format.
already-installed-[in]direct-link-profile
String, specifying the name of a file. This file must be located in the user/expansion/capa/
directory of the Antares study and has the same format as a [in]direct-link-profile
file, see Figure 5. The already-installed-[in]direct-link-profile
makes the link between the already installed capacity and the available capacity, in the direct and indirect way of the Antares link, for the 8760 hours of the year. More details are given in this section.
!!! Note The same file can be used for [in]direct-link-profile
and already-installed-[in]direct-link-profile
of one or more candidates.
!!! Note For simplicity, we often refer to [already-installed]-direct-link-profile
and [already-installed]-indirect-link-profile
link profiles as just [already-installed]-link-profile
in the sequel.
The parameters link-profile
, already-installed-capacity
and already-installed-link-profile
are used to define the link between the capacity installed by Antares-Xpansion, the already installed capacity and the truly available capacity in the Antares study, hour by hour and in both directions of the link, following the relationship presented in Figure 6.
These parameters are only useful if the candidates are grid reinforcement.
Figure 6 – Link between the capacity invested by Antares-Xpansion, and the capacity available in the Antares study.
By default, the link-profile
and already-installed-link-profile
contain only 1's, thus assuming perfect availability of the invested capacity.
The parameters link-profile
and already-installed-link-profile
are conventionally used to:
Figure 7 – Available hourly capacity of different types of power plants due to outages. Antares-Xpansion allows taking into account either an average hourly availability (purple line), which is still very different from the actual hourly availability over a year or a different profile for each Monte-Carlo year (green lines), more realistic.
If you use the average availability, to validate the results after running the Antares-Xpansion, it is preferable to re-simulate these outages according to a stochastic process by relaunching an Antares simulation with the capacities obtained by Antares-Xpansion in order to obtain the real production program with outages and RES intermittence varying according to the scenarios.
From Antares-Simulator 8.2, users can define different NTC chronicles for different Monte-Carlo years.
Briefly, users define any number of chronicles for each link. For each link, users can select (randomly or not) one of the said chronicles in a result we call scenario. Refer to Antares-Simulator documentation for more information.
In Antares-Xpansion, it is possible to use those scenarios to select a different link profile depending on the Monte-Carlo year. There are a few pre-requisites:
direct-link-profile
, indirect-link-profile
, already-installed-direct-link-profile
and already-installed-indirect-link-profile
must have the same number of columns.An example with two investments candidates, one in semi-base generation and one in network capacity, is given below.
The invested semi-base generation in area1
is shifted in the virtual node invest_semibase
. During the optimization process, the capacity of the link between area1
and invest_semibase
will be updated with the new invested capacity.
The candidates.ini
file for this example is the following one:
Another example with solar generation in a virtual node:
where pv1.txt
is a text file, located in the user/expansion/capa/
folder of the study, and which contains the load factor time series of the candidate, see Figure 5. When \(x\) MW of the candidate solar_power
are invested, the actual time series of available power is equal to the product of \(x\) and the time series pv1.txt
.
The same link in an Antares study can be the support of several investment candidates. The interest of such an approach can be :
The example in Figure 8 shows the case of an investment in photovoltaic production with three potentials of increasing cost.
Figure 8 – Three potentials of increasing investment cost that applies to the same link in the Antares study.
This only works with the Antares-Xpansion algorithm (Benders decomposition) if the costs are increasing and if the investment candidates with the same link have the same already-installed-capacity
and already-installed-link-profile
.
In this example, we show how to consider both an investment candidate and a decommissioning candidate on the same link. Candidates for decommissioning must be moved from their physical location to a virtual node as explained in Prepare the Antares study.
We strongly advise to explicitly specify candidates for decommissioning in the name
field of the candidates.ini
file (although this is not required by the tool), see Figure 9. This will ease the analysis of Antares-Xpansion output for the user.
By considering several investment candidates on the same link, it is possible to model both an investment and a decommissioning candidate.
max-investment
or max-units
\( \times\) unit-size
.annual-cost-per-mw
.max-investment
or max-units
\( \times\) unit-size
.annual-cost-per-mw
.An example of production process that can be decommissioned or expanded is given in Figure 9.
Figure 9 – Candidates for investment and decommissioning on the same link from an Antares study.
!!! warning The hourly availability time series of thermal generation CCG in Antares should be higher than the sum of currently installed and new potential buildable capacities (availability of CCG cluster in the virtual node \(fr_{ccg} > 330 \cdot 19 + 330 \cdot 50\) in this example).
!!! Remark If the user specifies an already-installed-capacity
for the decommissioning candidate, this capacity will not be decommissioned by Antares-Xpansion.
From the modelling of decommissioning candidates, it follows that the final result should be read "in the opposite way" compared to investment candidates:
fr_ccg_decommissioning
is 300 x 19 MW invested, this means that no unit is decommissioned.fr_ccg_decommissioning
is 0 MW invested, this means that all units have been decommissioned.