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Objects and Methods : Thermal : User Methods : Modified Load
Modified Load
This category allows the user to define load leveling on the thermal object. The category is dependent on selecting the Hourly Load method from the Load category. See Hourly Load and Load for details.
* None
This is the default no-action method.
* Calculate Modified Load
This method takes the System Load (original, unmodified load) and then subtracts the net generation from hydropower to get the Modified Load. It also adds slots to define load leveling in the thermal object. With the new slots, users can write policies that will level the load to the extent possible.
Slots Specific to This Method
 Modified Load
Type: Series Slot
Units: Energy
Description: Remaining load after hydropower is generated.
Information: The remaining load equals the original load minus the net generation from the hydropower sources selected in the Modified Load Power Sources Used table. See Modified Load Power Sources Used.
I/O: Output
 Modified Load Power Sources Used
Type: Table Slot
Units: None
Description: One row for each power source and one column with a positive value for power sources to be used.
Information: NaN indicates the power source doesn’t apply or has already been included in reducing the load.
I/O: Input only
Method Details 
Like all thermal method calculations, the method is called at the end of a simulation run. This method first calculates the original, unmodified load (as an energy) by adding the hourly system load and load adjustment slots for all hours within a time step.
The user selects the power sources that will be used to modify the load by setting values in the Modified Load Power Sources Used table. This table has one column and three rows: Conventional Hydro Power Evaluated, Pump Power Evaluated, and Allocated Energy Evaluated. Power sources that should be used to modify the load have a non-NaN value while unused sources have a NaN value. See Modified Load Power Sources Used for details.
The Modified Load initially equals the original load (System Load minus Load Adjustment). The net generation from the selected power sources are subtracted from this load. If any of the selected power sources have a value of NaN then the modified load is also NaN. For example, during a normal pre-optimization simulation, modified load will be NaN for all timesteps because hydropower generation is not yet known. In contrast, during a fully specified simulation or a post-optimization rulebased simulation, modified load will be calculated because all hydropower generations will be known. See Modified Load for details.
Allocated power is constrained by minimal and maximal power generation for each time period combined with periodic total energy requirements. The power is allocated to level the load in coordination with other power sources.
After calculating the individual economic components for each time period, the totals for all time periods are placed in the Linear Total Values table slot.
See Calculate Modified Load in Optimization for details on how the method is used in optimization.
Revised: 07/09/2023