Add new PEM and NG solid oxide fuel cell models

CHANGELOG.md

@@ -40,6 +40,7 @@
 - Added dynamic operating constraints (turndown, ramping, warm/cold start delays) to `AmmoniaSynLoopPerformanceModel` and split `AmmoniaSynLoopCostModel` into its own module. [PR 770](https://github.com/NatLabRockies/H2Integrate/pull/770)
 - Speed up the slowest tests in the suite by swapping the Floris wind model for `PYSAMWindPlantPerformanceModel` in examples 01 (`01_onshore_steel_mn`) and 02 (`02_texas_ammonia`), updating the affected `test_steel_example`/`test_simple_ammonia_example` expected values, fixing a pre-existing `cases.sql` cache-path bug and module-scoping the fixtures in `h2integrate/postprocess/test/test_sql_timeseries_to_csv.py` so the example only runs once for all four tests. [PR 782](https://github.com/NatLabRockies/H2Integrate/pull/782)
 - Exposed `n_timesteps`, `dt`, `plant_life`, and `fraction_of_year_simulated` as attributes on `CostModelBaseClass` (matching `PerformanceModelBaseClass`) and updated all cost and performance model subclasses across `h2integrate/` to use these attributes instead of reading them from `plant_config`, removing redundant boilerplate from individual components. [PR 783](https://github.com/NatLabRockies/H2Integrate/pull/783)
+- Added two new fuel cell models: `PEMH2FuelCellPerformanceModel` and `PEMH2FuelCellCostModel` to model a PEM hydrogen fuel cell and `SONGFuelCellPerformanceModel` and `SONGFuelCellCostModel` to model a natural gas solid oxide fuel cell [PR 794](https://github.com/NatLabRockies/H2Integrate/pull/794)
 
 ## 0.8 [April 15, 2026]
 

docs/_toc.yml

@@ -49,6 +49,8 @@ parts:
       - file: technology_models/iron_dri.md
       - file: technology_models/steel_eaf.md
       - file: technology_models/steel_eaf_cmu.md
+      - file: technology_models/PEM_fuel_cell.md
+      - file: technology_models/SO_NG_fuel_cell.md
   - caption: Storage Models
     chapters:
       - file: storage/storage_models_index.md

docs/technology_models/PEM_h2_fuel_cell.md

@@ -0,0 +1,49 @@
+# PEM Hydrogen Fuel Cell Model
+
+The PEM hydrogen fuel cell performance model implemented in H2Integrate is an electrochemical model that simulates the conversion of hydrogen and oxygen into electricity and water. The model uses a polynomial fit of an I-V (current-voltage) curve to determine the operating point of each cell based on the input `electricity_set_point`, then computes `hydrogen_consumed`, `oxygen_consumed`, `water_out`,  and `electricity_out` as the outputs of the system for each timestep.
+
+The model is sized by `system_capacity_kw` and `n_stacks`. The number of cells per stack is calculated from the stack size, a fixed cell active area (400 cm²)([1](https://www.energy.gov/sites/prod/files/2018/02/f49/fcto_battelle_mfg_cost_analysis_1%20_to_25kw_pp_chp_fc_systems_jan2017_0.pdf)), and a maximum cell power density. Hydrogen and oxygen availability is checked against the demand at each timestep. If the available oxygen or hydrogen is insuffucient for the requested power, the operating current is reduced to match the lowest available feedstock. Electricity output is clipped to the system capacity.
+
+There are no non-linear operational considerations in this model such as warm-up delays, degraded performance over operational life, voltage recalculation after current adjustment for limited feedstock supply, or thermal dynamics beyond a constant stack temperature input.
+
+The PEM hydrogen fuel cell cost model is implemented to use cost values in dollars per kilowatt (or per kilowatt per year), decomposed into capital cost components for the stack, hydrogen supply, air supply, cooling, controls and instrumentation, electrical, assembly, and additional labor.
+
+```{note}
+The I-V curve is currently internally defined in the model and not adjustable.
+```
+
+## Performance Model
+
+```{eval-rst}
+.. autoclass:: h2integrate.converters.hydrogen.PEM_h2_fuel_cell.PEMH2FuelCellPerformanceConfig
+   :members:
+   :undoc-members:
+   :show-inheritance:
+   :no-index:
+```
+
+```{eval-rst}
+.. autoclass:: h2integrate.converters.hydrogen.PEM_h2_fuel_cell.PEMH2FuelCellPerformanceModel
+   :members:
+   :undoc-members:
+   :show-inheritance:
+   :no-index:
+```
+
+## Cost Model
+
+```{eval-rst}
+.. autoclass:: h2integrate.converters.hydrogen.PEM_h2_fuel_cell.PEMH2FuelCellCostConfig
+   :members:
+   :undoc-members:
+   :show-inheritance:
+   :no-index:
+```
+
+```{eval-rst}
+.. autoclass:: h2integrate.converters.hydrogen.PEM_h2_fuel_cell.PEMH2FuelCellCostModel
+   :members:
+   :undoc-members:
+   :show-inheritance:
+   :no-index:
+```

docs/technology_models/SO_NG_fuel_cell.md

@@ -0,0 +1,49 @@
+# Solid Oxide Natural Gas Fuel Cell Model
+
+The solid oxide natural gas (SO NG) fuel cell performance model implemented in H2Integrate is an electrochemical model that simulates the conversion of natural gas (assumed to be methane in the chemical reaction equations), steam, and oxygen into electricity, water, and carbon dioxide. The model uses a polynomial fit of an I-V (current-voltage) curve to determine the operating point of each cell based on the input `electricity_set_point`, then computes `natural_gas_consumed`, `oxygen_consumed`, `water_out`, `carbon_dioxide_out`, and `electricity_out` as the outputs of the system for each timestep.
+
+The model is sized by `system_capacity_kw` and `n_stacks`. The number of cells per stack is calculated from the stack size, a fixed cell active area (400 cm²), and a maximum cell power density. Natural gas and oxygen consumption are computed from the cell current via Faraday's law assuming complete electrochemical oxidation of methane. The model uses the methane-reforming equation rather than a direct electrochemical methan-combusting reaction. This assumes that the methane is broken down in a steam-reforming process before the feedstock enteres the fuel cell ([1](https://www.sciencedirect.com/science/article/pii/S0360319906005726)). Electricity output is clipped to the system capacity.
+
+There are no non-linear operational considerations in this model such as warm-up delays, degraded performance over operational life, or thermal dynamics beyond a constant stack temperature input.
+
+The SO NG fuel cell cost model is implemented to use cost values in dollars per kilowatt (or per kilowatt per year), decomposed into capital cost components for the stack, fuel supply, air supply, cooling, controls and instrumentation, electrical, assembly, and additional labor.
+
+```{note}
+The I-V curve is currently internally defined in the model and not adjustable.
+```
+
+## Performance Model
+
+```{eval-rst}
+.. autoclass:: h2integrate.converters.natural_gas.SO_NG_fuel_cell.SONGFuelCellPerformanceConfig
+   :members:
+   :undoc-members:
+   :show-inheritance:
+   :no-index:
+```
+
+```{eval-rst}
+.. autoclass:: h2integrate.converters.natural_gas.SO_NG_fuel_cell.SONGFuelCellPerformanceModel
+   :members:
+   :undoc-members:
+   :show-inheritance:
+   :no-index:
+```
+
+## Cost Model
+
+```{eval-rst}
+.. autoclass:: h2integrate.converters.natural_gas.SO_NG_fuel_cell.SONGFuelCellCostConfig
+   :members:
+   :undoc-members:
+   :show-inheritance:
+   :no-index:
+```
+
+```{eval-rst}
+.. autoclass:: h2integrate.converters.natural_gas.SO_NG_fuel_cell.SONGFuelCellCostModel
+   :members:
+   :undoc-members:
+   :show-inheritance:
+   :no-index:
+```

examples/37_pem_fc/37_pem_fc.yaml

@@ -0,0 +1,5 @@
+name: H2Integrate_config
+system_summary: This reference contains a hydrogen fuel cell meeting an electricity demand
+driver_config: driver_config.yaml
+technology_config: tech_config.yaml
+plant_config: plant_config.yaml

examples/37_pem_fc/driver_config.yaml

@@ -0,0 +1,4 @@
+name: driver_config
+description: This analysis runs a hybrid plant to match the first example in H2Integrate
+general:
+  folder_output: outputs

examples/37_pem_fc/plant_config.yaml

@@ -0,0 +1,60 @@
+name: plant_config
+description: This plant is located in MN, USA...
+sites:
+  site:
+    latitude: 32.31714
+    longitude: -100.18
+# array of arrays containing left-to-right technology
+# interconnections; can support bidirectional connections
+# with the reverse definition.
+# this will naturally grow as we mature the interconnected tech
+technology_interconnections:
+   # connect feedstocks to fuel cell
+  - [h2_feedstock, PEM_fuel_cell, hydrogen, pipe]
+  - [o2_feedstock, PEM_fuel_cell, oxygen, pipe]
+   # connect fuel cell to demand component
+  - [PEM_fuel_cell, electricity_load_demand, electricity, cable]
+plant:
+  plant_life: 2
+finance_parameters:
+  finance_groups:
+    finance_model: ProFastLCO
+    model_inputs:
+      params:
+        analysis_start_year: 2032
+        installation_time: 36  # months
+        inflation_rate: 0.0  # 0 for real analysis
+        discount_rate: 0.06  # nominal return based on 2024 ATB baseline workbook for land-based wind
+        debt_equity_ratio: 0.724  # 2024 ATB uses 72.4% debt for land-based wind
+        property_tax_and_insurance: 0.025  # percent of CAPEX estimated based on https://www.nlr.gov/docs/fy25osti/91775.pdf https://www.house.mn.gov/hrd/issinfo/clsrates.aspx
+        total_income_tax_rate: 0.2574  # 0.257 tax rate in 2024 atb baseline workbook, value here is based on federal (21%) and state in MN (9.8)
+        capital_gains_tax_rate: 0.15  # H2FAST default
+        sales_tax_rate: 0.0  # average combined state and local sales tax https://taxfoundation.org/location/texas/
+        debt_interest_rate: 0.07  # based on 2024 ATB nominal interest rate for land-based wind
+        debt_type: Revolving debt  # can be "Revolving debt" or "One time loan". Revolving debt is H2FAST default and leads to much lower LCOH
+        loan_period_if_used: 0  # H2FAST default, not used for revolving debt
+        cash_onhand_months: 1  # H2FAST default
+        admin_expense: 0.00  # percent of sales H2FAST default
+      capital_items:
+        depr_type: MACRS   # can be "MACRS" or "Straight line"
+        depr_period: 7  # 5  years - for clean energy facilities as specified by the IRS MACRS schedule https://www.irs.gov/publications/p946#en_US_2020_publink1000107507
+        refurb: [0.]
+  cost_adjustment_parameters:
+    cost_year_adjustment_inflation: 0.025  # used to adjust modeled costs to target_dollar_year
+    target_dollar_year: 2022
+  finance_subgroups:
+    h2:
+      commodity: hydrogen
+      commodity_stream: h2_feedstock
+      technologies: [h2_feedstock]
+    o2:
+      commodity: oxygen
+      commodity_stream: o2_feedstock
+      technologies: [o2_feedstock]
+    electricity:
+      commodity: electricity
+      commodity_stream: PEM_fuel_cell
+      technologies:
+        - PEM_fuel_cell
+        - h2_feedstock
+        - o2_feedstock

examples/37_pem_fc/run_pem_fuel_cell.py

@@ -0,0 +1,18 @@
+import numpy as np
+
+from h2integrate import H2IntegrateModel
+
+
+# Create a H2Integrate model
+model = H2IntegrateModel("37_pem_fc.yaml")
+
+# Setup the model
+model.setup()
+
+# Set fuel cell demand profile
+demand_profile = np.ones(8760) * 1000
+model.prob.set_val("PEM_fuel_cell.electricity_set_point", demand_profile, units="kW")
+
+# Run model
+model.run()
+model.post_process()

examples/37_pem_fc/tech_config.yaml

@@ -0,0 +1,65 @@
+name: technology_config
+description: This hybrid plant produces ammonia
+technologies:
+  PEM_fuel_cell:
+    performance_model:
+      model: PEMH2FuelCellPerformanceModel
+    cost_model:
+      model: PEMH2FuelCellCostModel
+    model_inputs:
+      shared_parameters:
+        system_capacity_kw: 1500
+      performance_parameters:
+        n_stacks: 60
+        stack_temperature_K: 278  # Not used yet
+      cost_parameters:
+        capex_stack_per_kw: 800
+        capex_hydrogen_supply_per_kw: 140.67
+        capex_air_supply_per_kw: 138.79
+        capex_cooling_per_kw: 64.14
+        capex_controls_instrumentation_per_kw: 106.52
+        capex_electrical_per_kw: 447.83
+        capex_assembly_per_kw: 63.51
+        capex_additional_labor_per_kw: 137.96
+        fixed_opex_per_kw_per_year: 31
+        cost_year: 2026
+  electricity_load_demand:
+    performance_model:
+      model: GenericDemandComponent
+    model_inputs:
+      performance_parameters:
+        commodity: electricity
+        commodity_rate_units: kW
+        demand_profile: 1000
+  h2_feedstock:
+    performance_model:
+      model: FeedstockPerformanceModel
+    cost_model:
+      model: FeedstockCostModel
+    model_inputs:
+      shared_parameters:
+        commodity: hydrogen
+        commodity_rate_units: kg/h
+      performance_parameters:
+        rated_capacity: 50.0  # kg/h of hydrogen
+      cost_parameters:
+        cost_year: 2022
+        price: 5.0
+        annual_cost: 0.
+        start_up_cost: 0.0
+  o2_feedstock:
+    performance_model:
+      model: FeedstockPerformanceModel
+    cost_model:
+      model: FeedstockCostModel
+    model_inputs:
+      shared_parameters:
+        commodity: oxygen
+        commodity_rate_units: kg/h
+      performance_parameters:
+        rated_capacity: 400.0  # kg/h of oxygen
+      cost_parameters:
+        cost_year: 2022
+        price: 0.5  # $5/kg of oxygen. price is extremely variable
+        annual_cost: 0.
+        start_up_cost: 0.0

examples/38_song_fc/38_song_fc.yaml

@@ -0,0 +1,5 @@
+name: H2Integrate_config
+system_summary: This reference contains a hydrogen fuel cell meeting an electricity demand
+driver_config: driver_config.yaml
+technology_config: tech_config.yaml
+plant_config: plant_config.yaml

examples/38_song_fc/driver_config.yaml

@@ -0,0 +1,4 @@
+name: driver_config
+description: This analysis runs a hybrid plant to match the first example in H2Integrate
+general:
+  folder_output: outputs

examples/38_song_fc/plant_config.yaml

@@ -0,0 +1,60 @@
+name: plant_config
+description: This plant is located in MN, USA...
+sites:
+  site:
+    latitude: 32.31714
+    longitude: -100.18
+# array of arrays containing left-to-right technology
+# interconnections; can support bidirectional connections
+# with the reverse definition.
+# this will naturally grow as we mature the interconnected tech
+technology_interconnections:
+   # connect feedstocks to fuel cell
+  - [ng_feedstock, SONG_fuel_cell, natural_gas, pipe]
+  - [o2_feedstock, SONG_fuel_cell, oxygen, pipe]
+   # connect fuel cell to demand component
+  - [SONG_fuel_cell, electricity_load_demand, electricity, cable]
+plant:
+  plant_life: 2
+finance_parameters:
+  finance_groups:
+    finance_model: ProFastLCO
+    model_inputs:
+      params:
+        analysis_start_year: 2032
+        installation_time: 36  # months
+        inflation_rate: 0.0  # 0 for real analysis
+        discount_rate: 0.06  # nominal return based on 2024 ATB baseline workbook for land-based wind
+        debt_equity_ratio: 0.724  # 2024 ATB uses 72.4% debt for land-based wind
+        property_tax_and_insurance: 0.025  # percent of CAPEX estimated based on https://www.nlr.gov/docs/fy25osti/91775.pdf https://www.house.mn.gov/hrd/issinfo/clsrates.aspx
+        total_income_tax_rate: 0.2574  # 0.257 tax rate in 2024 atb baseline workbook, value here is based on federal (21%) and state in MN (9.8)
+        capital_gains_tax_rate: 0.15  # H2FAST default
+        sales_tax_rate: 0.0  # average combined state and local sales tax https://taxfoundation.org/location/texas/
+        debt_interest_rate: 0.07  # based on 2024 ATB nominal interest rate for land-based wind
+        debt_type: Revolving debt  # can be "Revolving debt" or "One time loan". Revolving debt is H2FAST default and leads to much lower LCOH
+        loan_period_if_used: 0  # H2FAST default, not used for revolving debt
+        cash_onhand_months: 1  # H2FAST default
+        admin_expense: 0.00  # percent of sales H2FAST default
+      capital_items:
+        depr_type: MACRS   # can be "MACRS" or "Straight line"
+        depr_period: 7  # 5  years - for clean energy facilities as specified by the IRS MACRS schedule https://www.irs.gov/publications/p946#en_US_2020_publink1000107507
+        refurb: [0.]
+  cost_adjustment_parameters:
+    cost_year_adjustment_inflation: 0.025  # used to adjust modeled costs to target_dollar_year
+    target_dollar_year: 2022
+  finance_subgroups:
+    # h2:
+    #   commodity: hydrogen
+    #   commodity_stream: h2_feedstock
+    #   technologies: [h2_feedstock]
+    # o2:
+    #   commodity: oxygen
+    #   commodity_stream: o2_feedstock
+    #   technologies: [o2_feedstock]
+    electricity:
+      commodity: electricity
+      commodity_stream: SONG_fuel_cell
+      technologies:
+        - SONG_fuel_cell
+        - ng_feedstock
+        - o2_feedstock

examples/38_song_fc/run_song_fuel_cell.py

@@ -0,0 +1,18 @@
+import numpy as np
+
+from h2integrate import H2IntegrateModel
+
+
+# Create a H2Integrate model
+model = H2IntegrateModel("38_song_fc.yaml")
+
+# Setup the model
+model.setup()
+
+# Set fuel cell demand profile
+demand_profile = np.ones(8760) * 1000
+model.prob.set_val("SONG_fuel_cell.electricity_set_point", demand_profile, units="kW")
+
+# Run model
+model.run()
+model.post_process()