Update pricetaker tutorial by jakechurchi · Pull Request #1822 · watertap-org/watertap

jakechurchi · 2026-06-21T23:33:46Z

Fixes/Resolves:

Addresses issue #1806

Summary/Motivation:

The current pricetaker tutorial was focused on one facility. This PR provides a more complicated example.

Changes proposed in this PR:

Adding a second tutorial notebook that has energy consumption as a function of both flowrate and recovery
Adds unit models and functions that allow modeling a facility for NAWI project 3.25

Legal Acknowledgement

By contributing to this software project, I agree to the following terms and conditions for my contribution:

I agree my contributions are submitted under the license terms described in the LICENSE.txt file at the top level of this directory.
I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.

…Notebook runs.

jakechurchi · 2026-06-23T00:20:00Z

+        results = solver.solve(m, tee=True)
+
+        # This is line that is causing the failure on Linux. But I don't know why.
+        # results = solver.solve(m)


This line is causing failure on Linux, but is fine on Windows. Unsure how to resolve the problem as the error output log gives almost no information

If there is a failure to converge to a solution, then it is usually because of an issue with initialization or scaling. It could also potentially have to do with problems in the formulation, but since you say the solve passes on Windows, I'd assume the former.

Did some testing with Kurby- It's a problem with the watertap solver, which just rejects the problem because it includes binary variables. Going to change to the IDAES solver.
The point of this "solve" is not to generate a real solution, but to allow the post_solve functions to be tested.

jakechurchi

Commenting to guide changes + make future reviewing easier

jakechurchi · 2026-06-23T00:24:14Z

+        assert hasattr(m, "posttreatment_unit_commitment_shutdown")
+
+        # Limit hours when start-ups and shutdowns can occur to reflect when operators are on-site
+        fs.add_working_hours_constraint(m)


Difficult to do assertions for this function because it only exists for a subset of the hours

jakechurchi · 2026-06-23T00:26:55Z

+    def test_add_expressions(self, system_frame):
+        m, price_data, peak_hours = system_frame
+
+        fs.add_useful_expressions(m)


I feel like this function should either be scrapped, or some of the functions below should be included.

Is there a reason to piece the build out like this rather than just having a single build function that does all the .add_{stuff} and returns the fully constructed model?

For testing purposes this division it helps identify where issues would arise. Also, some of the add functions are optional (ex. add_working_hours_constraint) so I wouldn't want that in the build function.

The ones that could be included in the build would probably be add_demand_and_fixed_costs, add_useful_expressions, and constrain_water_production.

jakechurchi · 2026-06-23T00:30:43Z

+    @pytest.mark.unit
+    def test_fixing_operations(self, system_frame):
+        m, price_data, peak_hours = system_frame
+        fs.fix_operations_for_first_four_days(m, peak_hours=peak_hours)


Is it worth adding assertions for this? Feel like I'm missing the point of those assert statements. If there is no error on calling the function, that means those expressions/vars/constraints were successfully created, right?

jakechurchi · 2026-06-23T00:33:22Z

This is a pretty rough diagram, but I want to establish the treatment steps, the parallel ro trains, and the costed flows.

jakechurchi · 2026-06-23T21:59:17Z

+
+
+def calculate_replacement_costs(m):
+    """Adds expression for the replacement cost"""


New, def needs documentation

jakechurchi · 2026-06-23T22:00:00Z

+        )
+
+
+def calculate_flexibility_metrics(


New, needs to be included in the documentation

jakechurchi · 2026-06-23T22:01:42Z

+    m.LVOF = Var(initialize=LVOF)
+
+
+def add_useful_expressions(m):


Highly consider expanding or deleting this

jakechurchi · 2026-06-23T22:04:06Z

+        )
+
+
+def fix_operations_for_first_four_days(m, peak_hours=None):


Also not used in tutorial example? Review the comments on this function

jakechurchi · 2026-06-23T22:05:21Z

+                )  # Plant must be on
+
+
+### NOT USED IN THE TUTORIAL EXAMPLE - That might mean they aren't being tested? ###


Revisit these functions after drafting the documentation and having some working tests

jakechurchi · 2026-06-24T15:51:22Z

@@ -21,7 +21,7 @@
 from watertap.flowsheets.flex_desal import wrd_ro_flowsheet as fs
 from watertap.flowsheets.flex_desal import utils
 from watertap.flowsheets.flex_desal.params import FlexDesalParams
-from watertap.core.solvers import get_solver
+from idaes.core.solvers import get_solver


Important to note WATERTAP get_solver will fail on Mac and Linux!

these notebooks aren't being tested yet but this will be an issue once they are

We will want #1824 to be merged before this. And potentially we should address #1835 in this PR? Or rename this "adding second pricetaker tutorial". Then a later PR can address the issue in the existing notebook

kurbansitterley

This is a totally new tutorial and flowsheet rather than an update to the existing tutorial, correct?

Because this PR would add two flex desal flowsheets and tutorials in the repository, before I go much further I'd like to see some changes to organization.

the two flowsheets/tutorials should be in their own directories within */flex_ro directories with their own assets/utility files
within their own directories any data/jsons/pngs should be in an assets folder or something (I know that other tutorials don't follow this convention but I think they should in a future mod)
in general I am not wild about wrd_ being prepended to all the WRD-inspired additions. It is not really descriptive to what the files are and will be lost on a new user approaching WaterTAP tutorials. I don't have any good suggestions atm, but - what is the primary difference between the two flowsheets?
our other tutorials have more descriptive names (sorta the same point as the last bullet) so I'd like to see mp_model and wrd_model changed at minimum

I know we are sorta on a time crunch so interested in what @adam-a-a thinks here.

jakechurchi · 2026-06-24T20:12:51Z

in general I am not wild about wrd_ being prepended to all the WRD-inspired additions. It is not really descriptive to what the files are and will be lost on a new user approaching WaterTAP tutorials. I don't have any good suggestions atm, but - what is the primary difference between the two flowsheets?

our other tutorials have more descriptive names (sorta the same point as the last bullet) so I'd like to see mp_model and wrd_model changed at minimum

This is a good point. I would say the biggest difference is that energy intensity is a function of flowrate in the WRD case. So naming convention could be "flex recovery" (for original tutorial) and "flex flow" for the WRD one?
Though WRD is flexible w.r.t. both flowrate and recovery.

Will wait for feedback before renaming everything though.

…utorial

jakechurchi · 2026-06-25T22:06:57Z

 # NOTE: This function is needed until Pyomo's Gurobi writer can handle
 # general nonlinear constraints. Once Pyomo supports this feature, this
 # function can be removed from the codebase. Since this function is
 # needed temporarily, tests are not added for this function.


If my understanding is correct, this test can be deleted because gurobi can deal with general nonlinear constraints?

jakechurchi · 2026-06-25T22:07:43Z

            solver.set_instance(m)
            return solver

        if m.params.surrogate_type == "quadratic_surrogate":


This would need to be like m.params.ro.surrogate_type

Jake Churchill added 18 commits June 9, 2026 13:49

initial commit adding a second tutorial notebook

45e3a42

Outline of tutorial

6dbac75

Adding additional pricesignal files

14a8eb5

Adding solar data and RO SEC surrogates

f8d788f

Changes to existing pricetaker functions and classes

cec4ff3

Adding classes, units, and functions for the WRD case study tutorial

f13b8a2

Creating a test that the pricetaker model used in the tutorial builds

377c61e

Pulling over scripts to run wrd Pricetaker

b909f7e

Created test file for more complex pricetaker build

0954036

Fixing pricetaker script

8c4e392

First version of the notebook which runs

fbb1a22

Added solves for the other rate structures and a results comparison. …

4505ef0

…Notebook runs.

Preparing to run tests with gurobi on Kestrel

4d28171

Changing format of slurm file

3c594ae

Adding a pytest config option

ed90853

Improving exaplanations in the tutorials

04598d1

black 26.3.1

be95f5b

Updated classmethod and reverted metadata in introduction.ipynb

2b15c44

kurbansitterley mentioned this pull request Jun 22, 2026

Some notebooks are not being tested #1823

Closed

Jake Churchill added 11 commits June 22, 2026 10:27

fixing typos in notebook

eb53d6c

changes to pass pylint test

7920819

remove assert_optimal_termination

52fef08

Adding basic schematic of facility to the tutorial

f049831

Commenting out the solve step

af7c5b4

pylint fixes

1ce79fd

changing options on ipopt solve test for linux failures

3b00357

Changing tests from units to components

6a7bb8f

change to allow kestrel run with gurobi

886dee0

Changing location of slurm test file

7207deb

Updating slurm file

b125ff8

Deleting files that were for testing on HPC

424ccf7

jakechurchi commented Jun 23, 2026

View reviewed changes

Jake Churchill added 3 commits June 23, 2026 17:11

Improving the notebook

00b26d2

Changed solver for test_wrd_pricetaker

6eb703b

addressing minor comments

be6d207

jakechurchi marked this pull request as ready for review June 24, 2026 15:48

jakechurchi requested review from MarcusHolly, avdudchenko, ksbeattie, kurbansitterley and sufikaur as code owners June 24, 2026 15:48

jakechurchi commented Jun 24, 2026

View reviewed changes

jakechurchi mentioned this pull request Jun 24, 2026

Flex RO Tutorial Documentation #1749

Open

kurbansitterley reviewed Jun 24, 2026

View reviewed changes

Comment thread watertap/flowsheets/flex_desal/wrd_unit_models.py Outdated

Comment thread watertap/flowsheets/flex_desal/tests/test_pricetaker_WRD.py Outdated

kurbansitterley reviewed Jun 24, 2026

View reviewed changes

Jake Churchill added 5 commits June 24, 2026 14:33

Add header and organize imports

fdd83e7

Delete unneeded test

4ed4afb

update classmethod for pricetaker test

f54890e

Name Change for files

ae2edcf

Merge remote-tracking branch 'upstream/main' into update_pricetaker_t…

f8c5628

…utorial

ksbeattie added the Priority:High High Priority Issue or PR label Jun 25, 2026

ksbeattie assigned jakechurchi Jun 25, 2026

jakechurchi commented Jun 25, 2026

View reviewed changes

This was referenced Jun 26, 2026

Preliminary fix for notebook testing issue #1824

Merged

Flex RO Tutorial is not being tested #1835

Open



		def calculate_replacement_costs(m):
		"""Adds expression for the replacement cost"""

		)


		def fix_operations_for_first_four_days(m, peak_hours=None):

		) # Plant must be on


		### NOT USED IN THE TUTORIAL EXAMPLE - That might mean they aren't being tested? ###

Uh oh!

Conversation

jakechurchi commented Jun 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Fixes/Resolves:

Summary/Motivation:

Changes proposed in this PR:

Legal Acknowledgement

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

jakechurchi left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

jakechurchi Jun 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

jakechurchi Jun 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

jakechurchi Jun 26, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

kurbansitterley left a comment

Choose a reason for hiding this comment

Uh oh!

jakechurchi commented Jun 24, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

jakechurchi commented Jun 21, 2026 •

edited

Loading

jakechurchi Jun 23, 2026 •

edited

Loading

jakechurchi Jun 23, 2026 •

edited

Loading

jakechurchi Jun 26, 2026 •

edited

Loading

jakechurchi commented Jun 24, 2026 •

edited

Loading