Finance Parameters

Finance Parameters#

Overview#

The finance_parameters section of the plant_config defines the financial subsystems of the plant. These parameters configure how costs, revenues, and investment metrics are calculated across all or parts of the modeled system.

Note

The plant_life parameter from the plant section of the plant_config is also used in finance calculations as the operating life of the plant.

At minimum, finance_parameters must include:

  • cost_adjustment_parameters:

    • target_dollar_year: dollar-year to convert costs to.

    • cost_year_adjustment_inflation: used to adjust costs for each technology from its native cost year to the target_dollar_year (see details on cost years and cost models here)

Other variables in finance_parameters vary depending on the financial analysis structure. There are two major modes of operation:

  • Single-model mode (default): All technologies are grouped together into a single financial calculation.

  • Subgroup mode: Technologies are split into one or more subgroups, each with its own commodity and one or more finance models.

Finance Groups vs. Finance Subgroups#

Within this framework, there are two distinct layers, finance groups and finance subgroups:

Finance groups#

A finance group contains the attributes needed to run one finance model:

  • finance_model: The name of the financial model to use (e.g., ProFastComp). Must correspond to one of the available models in self.supported_models.

  • model_inputs: A dictionary of parameters passed into the chosen finance model. These provide customization of assumptions such as discount rate, debt fraction, or cost escalation.

  • commodity (conditionally required): The product or service whose financial performance is being analyzed (e.g., hydrogen, electricity). Required if finance_subgroups are not used, otherwise defined within finance_subgroups.

Finance subgroups#

Subgroups are flexible collections of technologies that map to one or more finance groups. They allow you to:

  • Calculate financial metrics for only part of the system.

  • Compare different metrics of the same system (e.g., delivered vs. produced cost of hydrogen).

  • Run multiple models (e.g., LCOH, LCOE, LCOS, or NPV) on overlapping or distinct sets of technologies.

  • Model distributed or multi-location systems finances within a single plant configuration.

Subgroups contain information on how to construct the specific subgroup:

  • commodity: The product or service whose financial performance is being analyzed (e.g., hydrogen, electricity). Each finance subgroup is tied to a single commodity.

  • technologies: Technologies to include in the specific subgroup calculation (e.g., you might only want to include technologies that produce electricity in the levelized cost of energy calculation).

  • finance_groups: List of finance_groups that contain the finance_model and model_inputs. Required if multiple finance_groups are being used. Technology-specific finance_groups can be called by using the technology name listed in the tech_config (e.g., steel to use the steel specific finance model).

  • commodity_desc (optional): A text label to further distinguish outputs for a commodity. This is particularly useful when multiple finance models or subgroups reference the same commodity but need to produce separate outputs.

Important

If no subgroups are defined, a default subgroup is created that contains all technologies and references the default finance model and commodity defined in finance_groups.

Example finance configurations#

We'll now walk through three common configurations, highlighting the differences in the plant_config files and showcasing examples that use each approach.

Single-model (no subgroups)#

If no finance_subgroups are specified, all technologies are automatically grouped into a single default subgroup. In this case:

  • commodity and finance_model must be defined directly in finance_groups.

  • A default subgroup named default is created internally.

General format:

finance_parameters:
  finance_groups:
    commodity: "hydrogen"
    finance_model: "ProFastComp"
    model_inputs:
      discount_rate: 0.08

Outputs are named:

finance_subgroup_default.<finance_model_output>

Examples:

Single finance model with subgroups#

If finance_groups contains a single model definition, you may split technologies into multiple subgroups. Each subgroup defines its own commodity and list of technologies but uses the shared finance model.

In this case you see that the commodity is not defined within the finance_groups and is instead defined within the finance_subgroups. In this example there are two separate financial calculations one for subgroup_a, which is for the hydrogen commodity and one for subgroup_b, which is for the ammonia commodity and includes the "electrolyzer" and "asu". If you had additional technologies in your tech_config besides those, they would have to be included in the finance_subgroups to be included in the financial calculations.

General format:

finance_parameters:
  finance_groups:
    finance_model: "ProFastComp"
    model_inputs: #dictionary of inputs for ProFastComp
  finance_subgroups:
    subgroup_a:
      commodity: "hydrogen" #required
      technologies: ["electrolyzer"]
    subgroup_b:
      commodity: "ammonia" #required
      technologies: ["electrolyzer", "asu"]

Outputs are named:

finance_subgroup_<subgroup_name>.<finance_model_output>

Examples:

Note

Within finance_groups, the commodity, finance_model, and model_inputs may be placed under a named key for the finance group and indented one level deeper. This structure is optional when only a single finance model is used, but it is supported for consistency with the format required when specifying multiple finance models (see Specifying Multiple Finance Groups).

Multiple financial models with subgroups#

When multiple finance models are needed (e.g., to calculate both NPV and LCOH, or to compare multiple finance cases), multiple finance groups can be defined and assigned to subgroups.

General format:

finance_parameters:
  finance_groups:
    group_a:
      finance_model: "ProFastComp"
      model_inputs: {discount_rate: 0.08}
    group_b:
      finance_model: "NPVFinancial"
      model_inputs: {discount_rate: 0.05}
  finance_subgroups:
    subgroup_a:
      commodity: "hydrogen"
      finance_groups: ["group_a"]
      technologies: ["electrolyzer"]
    subgroup_b:
      commodity: "hydrogen"
      commodity_desc: "delivered"
      finance_groups: ["group_a", "group_b"]
      technologies: ["pipeline", "storage"]

Output naming:

  • If multiple finance groups are in the same subgroup, output names include the subgroup, commodity, description (if provided), and finance group name to avoid collisions in the OpenMDAO framework:

finance_subgroup_<subgroup_name>.<financial_model_output>_<commodity_desc>_<financial_group>
finance_subgroup_subgroup_a.LCOH_group_a
finance_subgroup_subgroup_b.LCOH_delivered_group_a
finance_subgroup_subgroup_b.NPV_hydrogen_delivered_group_b

Examples:

Key Behaviors#

  • If finance_parameters is missing --> no finance model is created.

  • If no finance_subgroups are defined → a default subgroup containing all technologies is created automatically.

  • Finance groups must not include a key named "default", as this is reserved for internal use.

  • Each subgroup must reference valid technology keys from technology_config['technologies']. Invalid keys raise errors.

  • Finance models must be listed in self.supported_models. Unknown models raise errors.

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