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Multi-year sell-price in ProFAST NPV #799

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3c03c3b
made it so profast npv can take in multi-year sell price costs
elenya-grant Jul 6, 2026
c6c922f
Merge remote-tracking branch 'h2i_upstream/develop' into npv/multi_ye…
elenya-grant Jul 6, 2026
62ae478
updated error handling for misisng sell price value
elenya-grant Jul 8, 2026
cf985dc
added subtest for inflation test
elenya-grant Jul 8, 2026
1b57833
Merge remote-tracking branch 'h2i_upstream/develop' into npv/multi_ye…
elenya-grant Jul 8, 2026
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27 changes: 22 additions & 5 deletions h2integrate/finances/profast_npv.py
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Original file line number Diff line number Diff line change
@@ -1,3 +1,6 @@
from collections.abc import Iterable

import numpy as np
from openmdao.utils.units import convert_units

from h2integrate.finances.tools import _compute_rate_units
Expand Down Expand Up @@ -40,7 +43,8 @@ def setup(self):

Retrieves the commodity sell price and its units from the plant configuration
and registers it as an input for the component. Calls the base `setup()` method
to initialize other ProFAST inputs and outputs.
to initialize other ProFAST inputs and outputs. The commodity sell price can be
either a scalar value or a list with the same length as plant life.

Raises:
ValueError: If `commodity_sell_price` or `commodity_sell_price_units` is not
Expand All @@ -53,8 +57,6 @@ def setup(self):
self.commodity_sell_price = model_inputs.get("commodity_sell_price", None)
self.commodity_sell_price_units = model_inputs.get("commodity_sell_price_units", None)

if self.commodity_sell_price is None:
raise ValueError("commodity_sell_price is missing as an input")
if self.commodity_sell_price_units is None:
raise ValueError(
"commodity_sell_price_units is missing as an input. "
Expand All @@ -65,9 +67,22 @@ def setup(self):

super().setup()

if self.commodity_sell_price is None:
raise ValueError("commodity_sell_price is missing as an input")

if isinstance(self.commodity_sell_price, Iterable):
if len(self.commodity_sell_price) != int(self.params.plant_life):
raise ValueError(
f"`commodity_sell_price` has an invalid length of "
f"{len(self.commodity_sell_price)}. `commodity_sell_price`"
f"must be the same length as the plant life ({self.params.plant_life}) "
"or a single value."
)

self.add_input(
f"sell_price_{self.output_txt}",
val=self.commodity_sell_price,
shape=int(self.params.plant_life),
units=self.commodity_sell_price_units,
)

Expand Down Expand Up @@ -112,6 +127,8 @@ def compute(self, inputs, outputs):
else:
pf = self.populate_profast(inputs)

outputs[f"NPV_{self.output_txt}"] = pf.cash_flow(
price=inputs[f"sell_price_{self.output_txt}"][0]
non_op_Nyears = int(np.ceil(self.params.installation_time / 12) + 1)
sell_profile = np.concatenate(
[np.zeros(non_op_Nyears), inputs[f"sell_price_{self.output_txt}"]]
)
outputs[f"NPV_{self.output_txt}"] = pf.cash_flow(price=sell_profile)
184 changes: 184 additions & 0 deletions h2integrate/finances/test/test_profast_npv.py
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Original file line number Diff line number Diff line change
@@ -1,3 +1,4 @@
import numpy as np
import pytest
import openmdao.api as om
from pytest import fixture
Expand Down Expand Up @@ -332,3 +333,186 @@ def test_profast_npv_nonstandard_price_units(
pytest.approx(prob.get_val("pf.NPV_electricity_no2", units="USD")[0], rel=1e-6)
== 611288384.412
)


@pytest.mark.regression
def test_profast_npv_multi_year_sell_price(
profast_inputs_no2, fake_filtered_tech_config, fake_cost_dict, subtests
):
mean_hourly_production = 500000.0
prob = om.Problem()
profast_inputs_no2["commodity_sell_price"] = [0.07] * 30
plant_config = {
"plant": {
"plant_life": 30,
},
"finance_parameters": {"model_inputs": profast_inputs_no2},
}
pf = ProFastNPV(
driver_config={},

@vijay092 vijay092 Jul 8, 2026

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Both test fixtures use inflation_rate: 0.0. Can you add a case with nonzero inflation to confirm the per-year array isn't getting escalated a second time by ProFAST's own calculation? If users are meant to supply already-nominal per-year prices, we may need to force infation_rate = 0 when an array is passed.

@vijay092 vijay092 Jul 8, 2026

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Also, could we clarify in the docs whether commodity_sell_price should be real or nominal dollars? Per our discussion with @jaredthomas68, we need to set nominal prices with inflation_rate = 0 (since ProFAST would otherwise apply its own escalation on top). Worth spelling that out explicitly.

@elenya-grant elenya-grant Jul 8, 2026 •
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Can you add a case with nonzero inflation to confirm the per-year array isn't getting escalated a second time by ProFAST's own calculation

I played around with ProFAST using a 2% inflation rate and have some info in case its useful:

  • pf.cash_flow(price=0.07) and pf.cash_flow(price=[0.7]*30) result in the same NPV
  • The NPV with an inflation rate of 2% is about 2.2x the NPV with 0 inflation (both using a sell price of 0.7)

I think ProFAST does escalate the sell price, it basically does this:

analysis_length = plant_life + (installation_period_months/12) 
analysis_years = np.arange(0, analysis_length + 1)
sales_price = commodity_sell_price*(1.0+inflation)**(analysis_years-1)
revenue_from_sales = sales_price*annual_production

Aka - the commodity sell price should provided

  • in non-escalated dollars (I think this means real - if I'm interpreting Jared's helpful doc page properly)
  • in the same cost year as set in plant_config["finance_parameters"]["cost_adjustment_parameters"]["target_dollar_year"] (the commodity_sell_price does not go through AdjustedCapexOpexComp)

I would be happy to update the docs! @jaredthomas68 - can you confirm that the commodity_sell_price should be input in real dollars?

@elenya-grant elenya-grant Jul 8, 2026 •
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Can yall (@vijay092 and @jaredthomas68) tell me whether this is True or false:

  • if using an inflation rate of 0 in ProFAST, then the commodity sell price should be provided in nominal dollars?
  • if using a nonzero inflation rate in ProFAST, then the commodity sell price should be provided in real dollars since ProFAST will escalate the price?

Can y'all look at the test h2integrate/finances/test/test_profast_npv.py::test_profast_npv_with_inflation and let me know what y'all think?

plant_config=plant_config,
tech_config=fake_filtered_tech_config,
commodity_type="electricity",
description="no2",
)

ivc = om.IndepVarComp()
ivc.add_output("rated_electricity_production", mean_hourly_production, units="kW")
ivc.add_output("capacity_factor", [1.0] * plant_config["plant"]["plant_life"], units="unitless")

prob.model.add_subsystem("ivc", ivc, promotes=["*"])
prob.model.add_subsystem("pf", pf, promotes=["rated_electricity_production", "capacity_factor"])
prob.setup()
for variable, cost in fake_cost_dict.items():
units = "USD" if "capex" in variable else "USD/year"
prob.set_val(f"pf.{variable}", cost, units=units)

prob.run_model()

with subtests.test("Sell price"):
assert (
pytest.approx(
prob.get_val("pf.sell_price_electricity_no2", units="USD/(kW*h)"), rel=1e-6
)
== profast_inputs_no2["commodity_sell_price"]
)

with subtests.test("NPV"):
assert (
pytest.approx(prob.get_val("pf.NPV_electricity_no2", units="USD")[0], rel=1e-6)
== 611288384.412
)


@pytest.mark.regression
def test_profast_npv_multi_year_error(profast_inputs_no2, fake_filtered_tech_config, subtests):
prob = om.Problem()
profast_inputs_no2["commodity_sell_price"] = [0.07] * 10
plant_config = {
"plant": {
"plant_life": 30,
},
"finance_parameters": {"model_inputs": profast_inputs_no2},
}
mean_hourly_production = 500000.0
pf = ProFastNPV(
driver_config={},
plant_config=plant_config,
tech_config=fake_filtered_tech_config,
commodity_type="electricity",
description="no2",
)

ivc = om.IndepVarComp()
ivc.add_output("rated_electricity_production", mean_hourly_production, units="kW")
ivc.add_output("capacity_factor", [1.0] * plant_config["plant"]["plant_life"], units="unitless")

prob.model.add_subsystem("ivc", ivc, promotes=["*"])
prob.model.add_subsystem("pf", pf, promotes=["rated_electricity_production", "capacity_factor"])

expected_message = "`commodity_sell_price` has an invalid length of 10"
with subtests.test("Incorrect sell price length"):
with pytest.raises(ValueError) as excinfo:
prob.setup()
assert expected_message in str(excinfo.value)


@pytest.mark.regression
def test_profast_npv_missing_sell_price(profast_inputs_no2, fake_filtered_tech_config, subtests):
prob = om.Problem()
profast_inputs_no2["commodity_sell_price"] = None
plant_config = {
"plant": {
"plant_life": 30,
},
"finance_parameters": {"model_inputs": profast_inputs_no2},
}
mean_hourly_production = 500000.0
pf = ProFastNPV(
driver_config={},
plant_config=plant_config,
tech_config=fake_filtered_tech_config,
commodity_type="electricity",
description="no2",
)

ivc = om.IndepVarComp()
ivc.add_output("rated_electricity_production", mean_hourly_production, units="kW")
ivc.add_output("capacity_factor", [1.0] * plant_config["plant"]["plant_life"], units="unitless")

prob.model.add_subsystem("ivc", ivc, promotes=["*"])
prob.model.add_subsystem("pf", pf, promotes=["rated_electricity_production", "capacity_factor"])

expected_message = "commodity_sell_price is missing as an input"
with subtests.test("Missing sell price"):
with pytest.raises(ValueError) as excinfo:
prob.setup()
assert expected_message in str(excinfo.value)


@pytest.mark.regression
def test_profast_npv_with_inflation(
profast_inputs_no2, fake_filtered_tech_config, fake_cost_dict, subtests
):
mean_hourly_production = 500000.0
prob = om.Problem()
price_escalation = 0.02 # 2% inflation in price
profast_inputs_no2["commodity_sell_price"] = [0.07] * 30
profast_inputs_no2["params"]["inflation_rate"] = price_escalation # 2% inflation
plant_config = {
"plant": {
"plant_life": 30,
},
"finance_parameters": {"model_inputs": profast_inputs_no2},
}
pf = ProFastNPV(
driver_config={},
plant_config=plant_config,
tech_config=fake_filtered_tech_config,
commodity_type="electricity",
description="no2",
)

ivc = om.IndepVarComp()
ivc.add_output("rated_electricity_production", mean_hourly_production, units="kW")
ivc.add_output("capacity_factor", [1.0] * plant_config["plant"]["plant_life"], units="unitless")

prob.model.add_subsystem("ivc", ivc, promotes=["*"])
prob.model.add_subsystem("pf", pf, promotes=["rated_electricity_production", "capacity_factor"])
prob.setup()
for variable, cost in fake_cost_dict.items():
units = "USD" if "capex" in variable else "USD/year"
prob.set_val(f"pf.{variable}", cost, units=units)

prob.run_model()

with subtests.test("Sell price (flat rate)"):
assert (
pytest.approx(
prob.get_val("pf.sell_price_electricity_no2", units="USD/(kW*h)"), rel=1e-6
)
== profast_inputs_no2["commodity_sell_price"]
)

# This NPV is about 2.2x times the NPV when inflation is zero
with subtests.test("NPV"):
assert (
pytest.approx(prob.get_val("pf.NPV_electricity_no2", units="USD")[0], rel=1e-6)
== 1336544230.1139889
)

nominal_price = np.concatenate(
[np.zeros(4), prob.get_val("pf.sell_price_electricity_no2", units="USD/(kW*h)")]
)
years = np.arange(0, 34, 1)
# Remove inflation from nominal price
real_price = nominal_price / ((1.0 + price_escalation) ** (years - 1))

prob.set_val("pf.sell_price_electricity_no2", real_price[4:], units="USD/(kW*h)")
prob.run_model()
# Removing inflation from nominal price gives NPV of 0.4 what is what before
with subtests.test("NPV (real sell price)"):
assert (
pytest.approx(prob.get_val("pf.NPV_electricity_no2", units="USD")[0], rel=1e-6)
== 520290489.52904046
)
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