Advice on performance tuning of MILP

Hi everyone!

I'm working on a power plant dispatchment model which has been becoming larger and larger (& slower and slower ;) ) lately. I'm using Excel with the plugin OpenSolver, which allows me to define an MILP problem in Excel but run it through Gurobi. Lately, solving just a tiny version of the model is taking longer than I expected. However, since I'm very unfamiliar with Gurobi and optimisation in general, I find it hard to read the log and figure out what kind of parameters I should tune to improve performance. Or perhaps it's already performing just fine and I just underestimated the computing time it would require.

I was wondering whether based on the solution log below, anyone can see whether or not I should perhaps tune some of the default solver parameters? I feel like since usually the most progress is achieved by heuristics, I should perhaps play around with parameters within the field of heuristics?

Thanks in advance!

Solution log:

"Obj: 68891 rows, 30261 columns, 76428260 nonzeros"
Set parameter MIPGap to value 0.05
Set parameter TimeLimit to value 2147483647
Set parameter IterationLimit to value 2147483647
Set parameter NodefileStart to value 0.5
Set parameter Threads to value 8
Gurobi Optimizer version 11.0.0 build v11.0.0rc2 (win64 - Windows 11+.0 (22631.2))

"CPU model: 11th Gen Intel(R) Core(TM) i7-11800H @ 2.30GHz, instruction set [SSE2|AVX|AVX2|AVX512]"
"Thread count: 8 physical cores, 16 logical processors, using up to 8 threads"

"Optimize a model with 68891 rows, 30261 columns and 76428260 nonzeros"
Model fingerprint: 0x30c3ee37
"Variable types: 13451 continuous, 16810 integer (16810 binary)"
Coefficient statistics:
"  Matrix range     [4e-04, 1e+05]"
"  Objective range  [1e-02, 6e+06]"
"  Bounds range     [1e+00, 1e+00]"
"  RHS range        [1e+00, 1e+05]"
Presolve removed 0 rows and 3 columns (presolve time = 5s) ...
Presolve removed 8405 rows and 3363 columns (presolve time = 13s) ...
Presolve removed 16811 rows and 3367 columns (presolve time = 17s) ...
Presolve removed 16814 rows and 3367 columns (presolve time = 20s) ...
Presolve removed 16814 rows and 5052 columns (presolve time = 35s) ...
Presolve removed 16814 rows and 5052 columns (presolve time = 77s) ...
Presolve removed 16814 rows and 5059 columns (presolve time = 92s) ...
Presolve removed 21851 rows and 5059 columns (presolve time = 96s) ...
Presolve removed 21851 rows and 5059 columns (presolve time = 100s) ...
Presolve removed 21851 rows and 5059 columns (presolve time = 105s) ...
Presolve removed 21851 rows and 5059 columns (presolve time = 110s) ...
Presolve removed 21851 rows and 5059 columns (presolve time = 117s) ...
Presolve removed 22050 rows and 5258 columns (presolve time = 120s) ...
Presolve removed 22050 rows and 5259 columns (presolve time = 126s) ...
Presolve removed 22050 rows and 5259 columns (presolve time = 130s) ...
Presolve removed 22066 rows and 5460 columns (presolve time = 137s) ...
Presolve removed 22071 rows and 5462 columns (presolve time = 140s) ...
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Presolve removed 22076 rows and 5471 columns (presolve time = 151s) ...
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Presolve removed 22076 rows and 5472 columns (presolve time = 169s) ...
Presolve removed 22076 rows and 5472 columns (presolve time = 172s) ...
Presolve removed 22076 rows and 5473 columns (presolve time = 181s) ...
Presolve removed 22076 rows and 5473 columns (presolve time = 188s) ...
Presolve removed 22076 rows and 5473 columns (presolve time = 190s) ...
Presolve removed 22076 rows and 5473 columns (presolve time = 195s) ...
Presolve removed 22076 rows and 5473 columns (presolve time = 200s) ...
Presolve removed 22076 rows and 5473 columns (presolve time = 206s) ...
Presolve removed 22276 rows and 5673 columns (presolve time = 210s) ...
Presolve removed 22276 rows and 5673 columns (presolve time = 215s) ...
Presolve removed 22276 rows and 5873 columns (presolve time = 220s) ...
Presolve removed 22279 rows and 5878 columns (presolve time = 225s) ...
Presolve removed 22282 rows and 5884 columns (presolve time = 232s) ...
Presolve removed 22284 rows and 5887 columns (presolve time = 235s) ...
Presolve removed 22284 rows and 5888 columns (presolve time = 244s) ...
Presolve removed 22284 rows and 5888 columns (presolve time = 247s) ...
Presolve removed 22284 rows and 5888 columns (presolve time = 253s) ...
Presolve removed 22284 rows and 5888 columns (presolve time = 256s) ...
Presolve removed 22284 rows and 5889 columns (presolve time = 265s) ...
Presolve removed 22284 rows and 5889 columns (presolve time = 272s) ...
Presolve removed 22284 rows and 5889 columns (presolve time = 275s) ...
Presolve removed 22284 rows and 5889 columns (presolve time = 280s) ...
Presolve removed 22284 rows and 5889 columns (presolve time = 285s) ...
Presolve removed 22484 rows and 6089 columns (presolve time = 292s) ...
Presolve removed 22484 rows and 6089 columns (presolve time = 297s) ...
Presolve removed 22484 rows and 6089 columns (presolve time = 301s) ...
Presolve removed 22486 rows and 6292 columns (presolve time = 307s) ...
Presolve removed 22488 rows and 6296 columns (presolve time = 311s) ...
Presolve removed 22490 rows and 6300 columns (presolve time = 315s) ...
Presolve removed 22492 rows and 6304 columns (presolve time = 328s) ...
Presolve removed 22492 rows and 6304 columns (presolve time = 330s) ...
Presolve removed 22492 rows and 6305 columns (presolve time = 340s) ...
Presolve removed 22492 rows and 6305 columns (presolve time = 340s) ...
Presolve removed 22492 rows and 6305 columns (presolve time = 345s) ...
Presolve removed 22692 rows and 6505 columns (presolve time = 352s) ...
Presolve removed 22692 rows and 6505 columns (presolve time = 355s) ...
Presolve removed 22692 rows and 6705 columns (presolve time = 360s) ...
Presolve removed 22696 rows and 6712 columns (presolve time = 367s) ...
Presolve removed 22698 rows and 6716 columns (presolve time = 371s) ...
Presolve removed 22700 rows and 6719 columns (presolve time = 375s) ...
Presolve removed 22700 rows and 6720 columns (presolve time = 384s) ...
Presolve removed 22700 rows and 6720 columns (presolve time = 387s) ...
Presolve removed 22700 rows and 6721 columns (presolve time = 396s) ...
Presolve removed 22700 rows and 6721 columns (presolve time = 401s) ...
Presolve removed 22900 rows and 6921 columns (presolve time = 406s) ...
Presolve removed 22900 rows and 6921 columns (presolve time = 410s) ...
Presolve removed 22900 rows and 7121 columns (presolve time = 416s) ...
Presolve removed 22903 rows and 7126 columns (presolve time = 421s) ...
Presolve removed 22905 rows and 7130 columns (presolve time = 425s) ...
Presolve removed 22908 rows and 7135 columns (presolve time = 431s) ...
Presolve removed 22908 rows and 7136 columns (presolve time = 440s) ...
Presolve removed 22908 rows and 7137 columns (presolve time = 452s) ...
Presolve removed 22908 rows and 7137 columns (presolve time = 457s) ...
Presolve removed 23108 rows and 7337 columns (presolve time = 462s) ...
Presolve removed 23108 rows and 7337 columns (presolve time = 465s) ...
Presolve removed 23108 rows and 7537 columns (presolve time = 471s) ...
Presolve removed 23111 rows and 7542 columns (presolve time = 477s) ...
Presolve removed 23113 rows and 7546 columns (presolve time = 481s) ...
Presolve removed 23115 rows and 7550 columns (presolve time = 485s) ...
Presolve removed 23116 rows and 7552 columns (presolve time = 495s) ...
Presolve removed 23116 rows and 7553 columns (presolve time = 507s) ...
Presolve removed 23116 rows and 7553 columns (presolve time = 512s) ...
Presolve removed 23359 rows and 7796 columns (presolve time = 517s) ...
Presolve removed 23359 rows and 7796 columns (presolve time = 521s) ...
Presolve removed 23481 rows and 8199 columns (presolve time = 526s) ...
Presolve removed 23543 rows and 8261 columns (presolve time = 530s) ...
Presolve removed 23549 rows and 8323 columns (presolve time = 536s) ...
Presolve removed 23549 rows and 8323 columns (presolve time = 541s) ...
Presolve removed 23549 rows and 8323 columns (presolve time = 545s) ...
Presolve removed 23549 rows and 8323 columns (presolve time = 558s) ...
Presolve removed 23557 rows and 8331 columns (presolve time = 560s) ...
Presolve removed 23557 rows and 8331 columns (presolve time = 565s) ...
Presolve removed 23557 rows and 8331 columns (presolve time = 570s) ...
Presolve removed 23557 rows and 8331 columns (presolve time = 580s) ...
Presolve removed 23953 rows and 8822 columns (presolve time = 580s) ...
Presolve removed 23953 rows and 8822 columns (presolve time = 585s) ...
Presolve added 0 rows and 4473 columns
Presolve removed 10658 rows and 0 columns
Presolve time: 587.08s
"Presolved: 58233 rows, 34734 columns, 16101952 nonzeros"
"Variable types: 11381 continuous, 23353 integer (10079 binary)"
"Deterministic concurrent LP optimizer: primal simplex, dual simplex, and barrier"
Showing barrier log only...

Root barrier log...

Elapsed ordering time = 5s
Elapsed ordering time = 6s
Elapsed ordering time = 9s
Elapsed ordering time = 10s
Ordering time: 10.63s

Barrier statistics:
 Dense cols : 9505
 AA' NZ     : 1.938e+07
 Factor NZ  : 1.091e+08 (roughly 1.0 GB of memory)
 Factor Ops : 6.667e+11 (roughly 3 seconds per iteration)
 Threads    : 5

                  Objective                Residual
Iter       Primal          Dual         Primal    Dual     Compl     Time
   0   2.26806564e+15 -1.91472050e+16  5.80e+10 1.32e+04  6.37e+12   637s
   1   6.90801157e+14 -7.08608026e+15  1.82e+10 3.40e+04  1.92e+12   642s
   2   8.89721930e+13 -2.96968348e+15  2.50e+09 3.14e+03  2.83e+11   648s
   3   2.45631849e+13 -9.39874964e+14  8.03e+07 6.52e+02  1.81e+10   654s
   4   1.96512907e+13 -1.63449332e+14  6.06e+06 1.26e+02  2.42e+09   660s
   5   7.86229452e+12 -1.05411865e+13  1.66e+06 4.71e+00  3.07e+08   665s
   6   1.96921398e+12 -3.91656052e+12  2.01e+05 1.42e+00  8.42e+07   672s
   7   4.85947627e+11 -9.23892262e+11  3.85e+04 2.56e-01  1.88e+07   678s
   8   5.62376101e+10 -9.23274028e+10  3.00e+03 9.59e-03  1.76e+06   685s
   9   4.82057429e+09 -1.11086987e+10  1.73e+02 1.87e-03  1.57e+05   692s
  10   6.33102549e+07 -7.93819862e+08  1.74e-09 2.73e-04  7.47e+03   698s
  11   2.03882078e+07 -2.37674457e+07  1.86e-09 4.02e-06  3.85e+02   705s
  12   1.53302288e+07 -4.93114384e+06  1.13e-09 1.56e-06  1.76e+02   711s
  13   8.73131931e+06  5.42531367e+06  3.47e-10 3.67e-07  2.88e+01   719s
  14   7.53293567e+06  6.21087926e+06  1.19e-10 1.40e-07  1.15e+01   726s
  15   7.17429523e+06  6.50975534e+06  5.86e-11 6.58e-08  5.79e+00   732s
  16   7.04109686e+06  6.60975466e+06  3.79e-11 4.43e-08  3.76e+00   739s

Barrier performed 16 iterations in 743.20 seconds (649.02 work units)
Barrier solve interrupted - model solved by another algorithm

Concurrent spin time: 10.24s

Solved with dual simplex

Root simplex log...

Iteration    Objective       Primal Inf.    Dual Inf.      Time
   22177    6.8120604e+06   0.000000e+00   0.000000e+00    754s

"Root relaxation: objective 6.812060e+06, 22177 iterations, 155.26 seconds (193.69 work units)"
Total elapsed time = 757.97s (DegenMoves)
Total elapsed time = 760.53s (DegenMoves)

    Nodes    |    Current Node    |     Objective Bounds      |     Work
 Expl Unexpl |  Obj  Depth IntInf | Incumbent    BestBd   Gap | It/Node Time

     0     0 6812060.44    0 1348          - 6812060.44      -     -  761s
H    0     0                    2.558719e+07 6812060.44  73.4%     -  812s
     0     0 6812189.15    0 1852 2.5587e+07 6812189.15  73.4%     -  830s
     0     0 6812294.20    0 2036 2.5587e+07 6812294.20  73.4%     -  898s
     0     0 6812320.97    0 2433 2.5587e+07 6812320.97  73.4%     -  913s
     0     0 6812335.05    0 2572 2.5587e+07 6812335.05  73.4%     -  927s
     0     0 6812335.05    0 2572 2.5587e+07 6812335.05  73.4%     -  947s
     0     2 6812335.05    0 2572 2.5587e+07 6812335.05  73.4%     - 1043s
     1     4 6812335.05    1 2573 2.5587e+07 6812335.05  73.4%   140 1047s
     3     8 6812335.05    2 2574 2.5587e+07 6812335.05  73.4%  75.3 1053s
     7    16 6812335.05    3 2575 2.5587e+07 6812335.05  73.4%  81.1 1066s
    15    24 6812335.05    4 2576 2.5587e+07 6812335.05  73.4%  86.4 1072s
    23    32 6813154.46    4 8427 2.5587e+07 6812335.05  73.4%  63.9 1078s
    31    40 6812335.05    5 2577 2.5587e+07 6812335.05  73.4%  55.9 1612s
    39    48 6813154.46    5 8428 2.5587e+07 6812335.05  73.4%  48.5 1619s
    47    60 6812335.05    6 2578 2.5587e+07 6812335.05  73.4%  48.3 1625s
    59    72 6813154.46    6 8420 2.5587e+07 6812335.05  73.4%  45.3 1631s
    71    85 6812335.05    7 2579 2.5587e+07 6812335.05  73.4%  41.1 1637s
    84    96 6813154.46    7 8424 2.5587e+07 6812335.05  73.4%  39.4 1643s
    95   110 6812335.05    8 2580 2.5587e+07 6812335.05  73.4%  37.9 1650s
   109   122 6813154.46    8 8431 2.5587e+07 6812335.05  73.4%  36.9 1657s
   121   135 6812335.05    9 2581 2.5587e+07 6812335.05  73.4%  36.6 1663s
   134   149 6813154.46    9 8433 2.5587e+07 6812335.05  73.4%  36.6 1672s
   148   165 6812335.05   10 2582 2.5587e+07 6812335.05  73.4%  36.2 1679s
   164   181 6812335.05   12 2584 2.5587e+07 6812335.05  73.4%  35.8 1687s
   180   197 6812335.05   14 2586 2.5587e+07 6812335.05  73.4%  35.1 1696s
   196   213 6812335.05   15 2587 2.5587e+07 6812335.05  73.4%  35.2 1705s
   212   230 6812335.05   16 2588 2.5587e+07 6812335.05  73.4%  35.3 1713s
   229   246 6812335.05   17 2589 2.5587e+07 6812335.05  73.4%  35.3 1722s
   245   262 6812335.05   18 2590 2.5587e+07 6812335.05  73.4%  35.3 1730s
   261   279 6812335.05   19 2591 2.5587e+07 6812335.05  73.4%  35.3 1739s
   278   298 6812335.05   20 2592 2.5587e+07 6812335.05  73.4%  35.3 1747s
   297   321 6812335.05   21 2593 2.5587e+07 6812335.05  73.4%  35.0 1757s
   320   344 6812335.05   22 2594 2.5587e+07 6812335.05  73.4%  34.5 1765s
   343   370 6812335.05   23 2595 2.5587e+07 6812335.05  73.4%  34.0 1776s
   369   392 6813154.46   25 8452 2.5587e+07 6812335.05  73.4%  33.3 1786s
   391   415 6812335.05   26 2598 2.5587e+07 6812335.05  73.4%  32.4 1796s
   414   436 6812335.05   27 2599 2.5587e+07 6812335.05  73.4%  31.9 1807s
   435   458 6812335.05   28 2600 2.5587e+07 6812335.05  73.4%  32.2 1817s
   457   475 6813159.95   31 8453 2.5587e+07 6812335.05  73.4%  32.1 1828s
   474   501 6812335.06   32 2604 2.5587e+07 6812335.05  73.4%  32.5 1840s
   500   527 6812335.06   34 2606 2.5587e+07 6812335.05  73.4%  32.7 1854s
   526   550 6812335.06   36 2608 2.5587e+07 6812335.05  73.4%  33.1 1866s
   549   582 6812335.06   38 2610 2.5587e+07 6812335.05  73.4%  33.5 1880s
   581   617 6812335.06   43 2615 2.5587e+07 6812335.05  73.4%  33.0 1895s
   616   662 6812335.06   48 2620 2.5587e+07 6812335.05  73.4%  31.9 1913s
   661   715 6812335.06   55 2627 2.5587e+07 6812335.05  73.4%  30.6 1938s
   714   795 6812335.06   63 2635 2.5587e+07 6812335.05  73.4%  29.8 1965s
   794   905 6812335.06   71 2643 2.5587e+07 6812335.05  73.4%  28.5 2590s
   904  1000 6812335.06   81 2653 2.5587e+07 6812335.05  73.4%  27.1 2627s
   999  1128 6812335.06   95 2667 2.5587e+07 6812335.05  73.4%  26.5 2672s
  1127  1292 6812335.06  112 2684 2.5587e+07 6812335.05  73.4%  25.8 2725s
  1291  1474 6812335.06  129 2701 2.5587e+07 6812335.05  73.4%  25.1 2784s
  1473  1702 6812335.06  152 2724 2.5587e+07 6812335.05  73.4%  24.5 2852s
  1701  1948 6812340.87  178 2746 2.5587e+07 6812335.05  73.4%  23.5 2928s
  1947  2246 6812343.15  208 2746 2.5587e+07 6812335.05  73.4%  22.2 3036s
  2245  2419 6812483.27  247 2745 2.5587e+07 6812335.05  73.4%  20.0 3122s
  2418  2515 6812493.67  248 2745 2.5587e+07 6812335.05  73.4%  18.8 3357s
H 2429  2515                    2.558185e+07 6812335.05  73.4%  18.7 3358s
  2514  2937 6812532.30  260 2746 2.5582e+07 6812335.05  73.4%  18.2 3517s
  2936  3396 6812987.25  333 2637 2.5582e+07 6812335.05  73.4%  16.0 3698s
  3395  3869 6813051.84  372 2668 2.5582e+07 6812335.05  73.4%  14.1 3890s
  3868  4369 6813197.81  401 2697 2.5582e+07 6812335.05  73.4%  12.6 4090s
  4368  4918 6813197.81  432 2721 2.5582e+07 6812335.05  73.4%  11.4 4300s
  4917  5613 6819408.33  487 2419 2.5582e+07 6812335.05  73.4%  10.3 4520s
H 5612  5621                    1.875565e+07 6812335.05  63.7%   9.1 5033s
H 5613  5621                    1.510742e+07 6812335.05  54.9%   9.1 5034s
H 5615  5621                    1.372574e+07 6812335.05  50.4%   9.1 5035s
H 5619  5621                    1.364192e+07 6812335.05  50.1%   9.1 5035s
  5620  5629 6819408.33  563 2495 1.3642e+07 6812335.05  50.1%   9.1 6050s
  5628  6268 6819408.33  564 2496 1.3642e+07 6812335.05  50.1%   9.1 6290s
  6267  7036 6819408.33  633 2565 1.3642e+07 6812335.05  50.1%   8.5 6521s
  7035  7806 6819408.33  713 2645 1.3642e+07 6812335.05  50.1%   8.5 6753s
H 7805  7804                    7033573.0564 6812335.05  3.15%   8.0 6918s
  7806  7805 6816825.07  819 2572 7033573.06 6812335.05  3.15%   8.0 8284s

Explored 7806 nodes (85254 simplex iterations) in 8288.32 seconds (9132.32 work units)
Thread count was 8 (of 16 available processors)

Solution count 7: 7.03357e+06 1.36419e+07 1.37257e+07 ... 2.55872e+07

Optimal solution found (tolerance 5.00e-02)
"Best objective 7.033573056390e+06, best bound 6.812335050544e+06, gap 3.1455%"