Thermosyphon_REopt_Analysis

Installing code dependencies

The Julia dependencies can be installed within Julia. See https://julialang.org/downloads to get the latest Julia version. Then run the following from this repository's top directory:

julia --project=.
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.7.2 (2022-02-06)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

julia> import Pkg

julia> Pkg.instantiate()

REopt Inputs

The master branch of REopt.jl package has online documentation (you can also find the documentation linked in the Github repository README.md). REopt inputs are provided either from a JSON file or a Julia dictionary. Note that if we removed a technology key from the JSON file then this technology would not be evaluated.

The file data/thermosyphon_scenario.json contains a base set of inputs to be used for an analysis sizing PV with BESS to supply a thermosyphon. For an off-grid system, the ElectricUtility inputs outage_start_time_step and outage_end_time_step are set to 1 and 8760 respectively, and the inputs provided in ElectricTariff aren't used. You may want to modify PV and Financial inputs to reflect your conditions.

This repository uses a custom branch of the REopt.jl package that includes a thermosyphon model. By including the Thermosyphon key, a thermosyphon will be included in the optimization, using default values for any inputs not provided. Possible inputs for the thermosyphon model are:

Name	Type	Default
ambient_temp_degF	Array{<:Real,1}	TMY profile
ground_temp_degF	Real	25
passive_to_active_cutoff_temp_degF	Real	20
effective_conductance_btu_per_degF	Real	141
fixed_active_cooling_rate_kw	Real	0.345
COP_curve_points_ambient_temp_degF	Array{<:Real,1}	[46, 52, 63]
COP_curve_points_COP_kw_per_kw	Array{<:Real,1}	[9, 6, 3]
structure_heat_to_ground_mmbtu_per_year	Real	5.9

Thermosyphon coefficient of performance can be modeled as a flat value by providing a single value for COP_curve_points_COP_kw_per_kw. Alternatively, COP can be modeled as a piecewise function, defined by a list of points. In this case, COP_curve_points_ambient_temp_degF and COP_curve_points_COP_kw_per_kw are the temperature and COP values respectively of those points. Defaults for these are used when neither input is provided.

Running Julia code

The file src/main.jl is this project's main script to run analyses of DERs to supply a thermosyphon. This script defines sites and climate warming scenarios to run, chosen BESS size and cost, PV costs, solver package, and optimization parameters to balance precision and solve time. The script then runs REopt for these scenarios, which each produces a JSON file of results (thermosyphon_results_ &ltsite>_ &ltwarming scenario>.json). Finally, key results are summarized in CSV for each site (&ltsite>_results_summary.csv). Modify src/main.jl and data/thermosyphon_scenario.json as desired and then run the following from this repository's top directory:

julia --project=.
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.7.2 (2022-02-06)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |


julia> include("src/main.jl")