Model Inputs/Outputs

The model requires several input parameters, provided via input files. These parameters, their dimensions, and descriptions are as follows:

Inputs

The parameters used, their desciptions, and their input file name in the model are as follows:

Parameters

Parameter [Unit]

Description

Input file 1

historical capacity 2

[MW]

The capacity of each technology in each zone for each year, taking into account the number of years that each technology has been in operation starting from the beginning of the planning period.

historical_capacity

capacity factor [N/A]

Capacity factor of different non-dispatchable technologies.

capacity_factor

carbon emission

limit [tCO2]

Carbon emission limit of different zones.

carbon_emission_limit

emission factor

[tCO2/MWh]

Emission factor of different technologies.

carbon_content

water delay time [N/A]

Water delay time of connection between reservoirs.

water_delay_time

demand [MW]

Demand of different balancing authorities.

demand

discount factor [N/A]

Discount factor for each year.

discount_factor

distance [km]

Distance of different pair of zones.

distance

discharge efficiency [N/A]

Discharge efficiency of storage technologies.

discharge_

efficiency

charge efficiency [N/A]

Charge efficiency of storage technologies.

charge_

efficiency

power to

energy ratio [MW/MWh]

Power to energy ratio ratio of storage technologies.

power_to_

energy_ratio

fuel price [dollar/MWh]

Fuel price of different technologies.

fuel_price

hydropower 3 [MW]

Predefined hydropower output of all reservoirs.

hydropower

inflow [m3/s]

Inflow of all reservoirs.

inflow

initial energy

storage level [1/MWh]

Initial energy storage level of different storage technologies.

initial_energy_

storage_level

lifetime [yr]

Lifetime of different technologies.

lifetime

new technology

lower bound [MW]

Lower bound of newly-built installed capacity of different technologies for each investment year.

new_technology_

lower_bound

new technology

upper bound [MW]

Upper bound of newly-built installed capacity of different technologies for each investment year.

new_technology_

upper_bound

ramp down [1/MW]

Ramp down rate of different technologies.

ramp_down

ramp up [1/MW]

Ramp up rate of different technologies.

ramp_up

reservoir characteristics

[As per data sheet]

Reservoir characteristics data includes designed water head, maximum storage, minimum storage, operational efficiency, area of affiliation, installed capacity, maximum power output, minimum power output, maximum outflow, minimum outflow, and maximum generation outflow.

reservoir_

characteristics

reservoir storage

lower bound [m3]

Lower bound of volume of hydropower reservoirs.

reservoir_storage_

lower_bound

final reservoir

storage level [m3]

Final volume of hydropower reservoirs.

final_reservoir_

storage_level

initial reservoir

storage level [m3]

Initial volume of hydropower reservoirs.

initial_reservoir_

storage_level

reservoir storage

upper bound [m3]

Upper bound of volume of hydropower reservoirs.

reservoir_storage

_upper_bound

Investmented OM cost

[dollar/MW/yr]

Fixed operation and maintenance cost of different technologies.

technology_fixed_

OM_cost

technology investment

cost [dollar/MW]

Investment cost of different technologies.

technology_investment

_cost

technology portfolio [MW]

Existing total installed capacity across all zones.

technology_

portfolio

technology

upper bound 4 [MW]

Upper bound of installed capacity of different technologies.

technology_upper_

bound

technology variable

OM cost [dollar/MWh]

Variable operation and maintenance costs of different technologies.

technology_variable_

OM_cost

transmission line

investment cost

[dollar/MW/km]

Investment cost of transmission lines (if there is no exising nor planned transmission lines between two specific zones, leave the data entries blank).

transmission_line_

investment_cost

transmission line

efficiency [N/A]

Efficiency of transmission lines across all zones.

transmission_line_

efficiency

transmission line

fixed OM cost

[dollar/MW]

Fixed operation and maintenance costs of transmission lines.

transmission_line_

fixed_OM_cost

transmission line

variable OM cost

[dollar/MWh]

Variable operations and maintenance costs of transmission lines.

transmission_line

_variable_cost

transmission line

lifetime [yr]

Lifetime of transmission lines.

transmission_line_

lifetime

technology type [N/A]

Categories of different technologies.

technology_type

reservoir tailrace

level-discharge function

[m & m3/s]

Relationship between tailrace level and total discharge for different reservoirs.

reservoir_tailrace_

level_discharge_

function

reservoir forebay

level-volume function

[m & m3]

Relationship between forebay level and volume for different reservoirs

reservoir_forebay_

level_volume_

function

Note

  • inf refers to Infinity, indicating that there is no upper bound.

  • None refers to a null value for current item.

Outputs

The output of the model is stored in a NetCDF file, please refer to this simple tutorial and official documentation of Xarray to understand how to manipulate NetCDF files.

The output file contains the following variables:

Output Variables

Variable name [Unit]

Description

trans_import_v [MW]

The electrical power transmitted from Zone 1 and effectively received by Zone 2 through the transmission line, after adjusting for transmission losses.

trans_export_v [MW]

The electrical power initially sent out by Zone 1 for transmission to Zone 2 via the transmission line, before adjusting for any transmission and distribution losses during its journey to Zone 2.

gen_v [MW]

Generated electricity from different technologies.

install_v [MW]

Existing installed capacity of different technologies.

carbon_v [Ton]

Carbon emissions across different years.

charge_v [MW]

Charged electricity of different storage technologies.

cost_v [dollar]

Total cost over the planning period.

cost_var_v [dollar]

Variable cost over the planning period.

cost_fix_v [dollar]

Fixed cost over the planning period.

cost_new_v [dollar]

Investment cost of technologies over the planning period.

cost_newline_v [dollar]

Investment cost of transmission lines over the planning period.

income_v [dollar]

Saved cost due to abstracted water resources over the planning period.

genflow_v [m3/s]

Generated water flow of different reservoirs.

spillflow_v [m3/s]

Spilled water flow of different reservoirs.

Execute various scenarios

By employing command-line parameters, you can execute different scenarios using the model. For example, if you wish to run a scenario referred to as "low demand," you can prepare input data named demand_low.xlsx. Subsequently, when running the model, you can utilize command-line parameters to specify the scenario value. For instance, you can execute the model by executing the command python run.py --demand=low.

Tuning Model Parameters

This section will guide you on how to tune the PREP-SHOT model parameters to compute the energy system for your needs. After you have prepared your input data based on the previous sections, you can proceed to tune the model parameters before you run it.

Within the root directory of the model, you will find a JSON file containing the parameters that you can tune for the model, named config.json. This file contains the following parameters:

Model Parameter

Description

input_folder

Specifies the name of the folder containing the input data.

output_filename

Specifies the name of the output file.

hour

Specifies the number of hours in each time period.

month

Specifies the number of months in each time period.

dt

Specifies the timestep for the simulation in hours.

hours_in_year

Specifies the number of hours in a year. Typically, this is set to 8760.

ishydro

Specifies whether to include hydropower in the optimization problem.

error_threshold

Specifies the error threshold for the model, while iterating for a solution. This parameter controls the convergence of the hydro model.

iteration_number

Specifies the maximum number of iterations for the hydro model, while iterating for a solution.

solver

Specifies the solver to be used for the optimization problem.

timelimit

Specifies the maximum time limit for the solver to solve the optimization problem in seconds.

After you have tuned the parameters, you can run the model by following the steps in the Installation page.

You can also try out the model with the sample data provided in the input folder. Refer to the Model Inputs/Outputs page for a walkthrough of this example, inspried by real-world data.

Footnotes

1

The input files format is .xlsx.

2

For instance, assuming the planning period spans from 2020 to 2050, with 2020 being the starting point, let's consider a technology that has been in operation since 2019. In this case, 2020 would mark its 2nd year of operation within the planning period. These inputs are useful for modelling the retirement of existing technologies.

3

To model the simplified hydropower operation.

4

To model the potential of technologies with land, fuel, and water constraints.