From d759256343404b4d7711f4e886427ccc8c3f9b0a Mon Sep 17 00:00:00 2001
From: Radhakrishna <radhakrishnatg@gmail.com>
Date: Fri, 26 May 2023 08:53:07 -0400
Subject: [PATCH] Switch to opensource solver cbc if Gurobi is not available

---
 .../nuclear_flowsheet_double_loop.ipynb       | 25 ++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/dispatches/case_studies/nuclear_case/nuclear_flowsheet_double_loop.ipynb b/dispatches/case_studies/nuclear_case/nuclear_flowsheet_double_loop.ipynb
index 05018eb9..14c7a327 100644
--- a/dispatches/case_studies/nuclear_case/nuclear_flowsheet_double_loop.ipynb
+++ b/dispatches/case_studies/nuclear_case/nuclear_flowsheet_double_loop.ipynb
@@ -1,6 +1,7 @@
 {
  "cells": [
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "compatible-panic",
    "metadata": {},
@@ -19,6 +20,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "5fddaa2d",
    "metadata": {},
@@ -49,6 +51,7 @@
     "import sys\n",
     "import pandas as pd\n",
     "import matplotlib.pyplot as plt\n",
+    "import pyomo.environ as pyo\n",
     "\n",
     "# Imports from the IDAES package\n",
     "from idaes.apps.grid_integration import Tracker\n",
@@ -62,10 +65,16 @@
     "from prescient.simulator import Prescient\n",
     "\n",
     "# Import nuclear flowsheet\n",
-    "from dispatches.case_studies.nuclear_case.nuclear_flowsheet_multiperiod_class import MultiPeriodNuclear"
+    "from dispatches.case_studies.nuclear_case.nuclear_flowsheet_multiperiod_class import MultiPeriodNuclear\n",
+    "\n",
+    "for solver in ('xpress_direct', 'gurobi', 'cbc'):\n",
+    "    if pyo.SolverFactory(solver).available(exception_flag=False):\n",
+    "        milp_solver = solver\n",
+    "        break"
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "80eee487",
    "metadata": {},
@@ -141,6 +150,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "5d5740c5",
    "metadata": {},
@@ -169,6 +179,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "278f755c",
    "metadata": {},
@@ -191,6 +202,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "cadef696",
    "metadata": {},
@@ -503,6 +515,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "52783019",
    "metadata": {},
@@ -531,6 +544,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "770f457e",
    "metadata": {},
@@ -9888,9 +9902,9 @@
     "    \"ruc_mipgap\": 0.01,\n",
     "    \"symbolic_solver_labels\": True,\n",
     "    \"reserve_factor\": 0.0,\n",
-    "    \"deterministic_ruc_solver\": \"gurobi\",\n",
+    "    \"deterministic_ruc_solver\": milp_solver,\n",
     "    \"output_ruc_solutions\": True,\n",
-    "    \"sced_solver\": \"gurobi\",\n",
+    "    \"sced_solver\": milp_solver,\n",
     "    \"print_sced\": True,\n",
     "    \"enforce_sced_shutdown_ramprate\": True,\n",
     "    \"plugin\": {\n",
@@ -9906,6 +9920,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "9185fe56",
    "metadata": {},
@@ -9914,6 +9929,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "8af866d1",
    "metadata": {},
@@ -9969,6 +9985,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "545e4163",
    "metadata": {},
@@ -10024,6 +10041,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "d3e1deab",
    "metadata": {},
@@ -10032,6 +10050,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "id": "2374a7e6",
    "metadata": {},