Note

You can download this example as a Jupyter notebook or start it in interactive mode.

Redispatch Example with SciGRID network#

In this example, we compare a 2-stage market with an initial market clearing in two bidding zones with flow-based market coupling and a subsequent redispatch market (incl. curtailment) to an idealised nodal pricing scheme.

[1]:

import pypsa
import matplotlib.pyplot as plt
import cartopy.crs as ccrs
from pypsa.descriptors import get_switchable_as_dense as as_dense

[2]:

solver = "cbc"

Load example network#

[3]:

o = pypsa.examples.scigrid_de(from_master=True)
o.lines.s_max_pu = 0.7
o.lines.loc[["316", "527", "602"], "s_nom"] = 1715
o.set_snapshots([o.snapshots[12]])

WARNING:pypsa.io:Importing network from PyPSA version v0.17.1 while current version is v0.25.0. Read the release notes at https://pypsa.readthedocs.io/en/latest/release_notes.html to prepare your network for import.
INFO:pypsa.io:Imported network scigrid-de.nc has buses, generators, lines, loads, storage_units, transformers

[4]:

n = o.copy()  # for redispatch model
m = o.copy()  # for market model

[5]:

o.plot();

/home/docs/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.25.0/lib/python3.11/site-packages/cartopy/mpl/style.py:76: UserWarning: facecolor will have no effect as it has been defined as "never".
  warnings.warn('facecolor will have no effect as it has been '

../_images/examples_scigrid-redispatch_6_1.png

Solve original nodal market model `o`#

First, let us solve a nodal market using the original model o:

[6]:

o.optimize(solver_name=solver)

WARNING:pypsa.components:The following transformers have zero r, which could break the linear load flow:
Index(['2', '5', '10', '12', '13', '15', '18', '20', '22', '24', '26', '30',
       '32', '37', '42', '46', '52', '56', '61', '68', '69', '74', '78', '86',
       '87', '94', '95', '96', '99', '100', '104', '105', '106', '107', '117',
       '120', '123', '124', '125', '128', '129', '138', '143', '156', '157',
       '159', '160', '165', '184', '191', '195', '201', '220', '231', '232',
       '233', '236', '247', '248', '250', '251', '252', '261', '263', '264',
       '267', '272', '279', '281', '282', '292', '303', '307', '308', '312',
       '315', '317', '322', '332', '334', '336', '338', '351', '353', '360',
       '362', '382', '384', '385', '391', '403', '404', '413', '421', '450',
       '458'],
      dtype='object', name='Transformer')
WARNING:pypsa.components:The following transformers have zero r, which could break the linear load flow:
Index(['2', '5', '10', '12', '13', '15', '18', '20', '22', '24', '26', '30',
       '32', '37', '42', '46', '52', '56', '61', '68', '69', '74', '78', '86',
       '87', '94', '95', '96', '99', '100', '104', '105', '106', '107', '117',
       '120', '123', '124', '125', '128', '129', '138', '143', '156', '157',
       '159', '160', '165', '184', '191', '195', '201', '220', '231', '232',
       '233', '236', '247', '248', '250', '251', '252', '261', '263', '264',
       '267', '272', '279', '281', '282', '292', '303', '307', '308', '312',
       '315', '317', '322', '332', '334', '336', '338', '351', '353', '360',
       '362', '382', '384', '385', '391', '403', '404', '413', '421', '450',
       '458'],
      dtype='object', name='Transformer')
INFO:linopy.model: Solve linear problem using Cbc solver
INFO:linopy.io: Writing time: 0.12s
INFO:linopy.constants: Optimization successful:
Status: ok
Termination condition: optimal
Solution: 2485 primals, 5957 duals
Objective: 3.01e+05
Solver model: not available
Solver message: Optimal - objective value 301209.38232509


INFO:pypsa.optimization.optimize:The shadow-prices of the constraints Kirchhoff-Voltage-Law were not assigned to the network.

Welcome to the CBC MILP Solver
Version: 2.10.10
Build Date: Apr 19 2023

command line - cbc -printingOptions all -import /tmp/linopy-problem-hpadc7cd.lp -solve -solu /tmp/linopy-solve-nfzij521.sol (default strategy 1)
Option for printingOptions changed from normal to all
Presolve 615 (-5342) rows, 1082 (-1403) columns and 4224 (-7082) elements
Perturbing problem by 0.001% of 2240.9252 - largest nonzero change 0.00094377425 ( 0.0088270484%) - largest zero change 0.00094089326
0  Obj -9.1138695 Primal inf 1289853.6 (567)
87  Obj -9.1138695 Primal inf 940906.71 (541)
171  Obj -8.5089326 Primal inf 891292.39 (504)
258  Obj -6.6574673 Primal inf 869484.27 (447)
345  Obj -5.4587969 Primal inf 1604841.1 (408)
421  Obj -4.0325276 Primal inf 3092684.7 (351)
490  Obj 4000.4139 Primal inf 18936833 (303)
567  Obj 4002.4125 Primal inf 11347402 (231)
644  Obj 112977.6 Primal inf 17298.159 (97)
731  Obj 292413.79 Primal inf 2041.4246 (29)
760  Obj 301212.33
Optimal - objective value 301209.38
After Postsolve, objective 301209.38, infeasibilities - dual 0 (0), primal 0 (0)
Optimal objective 301209.3823 - 760 iterations time 0.122, Presolve 0.02
Total time (CPU seconds):       0.16   (Wallclock seconds):       0.12

[6]:

('ok', 'optimal')

Costs are 301 k€.

Build market model `m` with two bidding zones#

For this example, we split the German transmission network into two market zones at latitude 51 degrees.

You can build any other market zones by providing an alternative mapping from bus to zone.

[7]:

zones = (n.buses.y > 51).map(lambda x: "North" if x else "South")

Next, we assign this mapping to the market model m.

We re-assign the buses of all generators and loads, and remove all transmission lines within each bidding zone.

Here, we assume that the bidding zones are coupled through the transmission lines that connect them.

[8]:

for c in m.iterate_components(m.one_port_components):
    c.df.bus = c.df.bus.map(zones)

for c in m.iterate_components(m.branch_components):
    c.df.bus0 = c.df.bus0.map(zones)
    c.df.bus1 = c.df.bus1.map(zones)
    internal = c.df.bus0 == c.df.bus1
    m.mremove(c.name, c.df.loc[internal].index)

m.mremove("Bus", m.buses.index)
m.madd("Bus", ["North", "South"]);

Now, we can solve the coupled market with two bidding zones.

[9]:

m.optimize(solver_name=solver)

INFO:linopy.model: Solve linear problem using Cbc solver
INFO:linopy.io: Writing time: 0.09s
INFO:linopy.constants: Optimization successful:
Status: ok
Termination condition: optimal
Solution: 1561 primals, 3185 duals
Objective: 2.14e+05
Solver model: not available
Solver message: Optimal - objective value 213988.68595810


INFO:pypsa.optimization.optimize:The shadow-prices of the constraints Kirchhoff-Voltage-Law were not assigned to the network.

Welcome to the CBC MILP Solver
Version: 2.10.10
Build Date: Apr 19 2023

command line - cbc -printingOptions all -import /tmp/linopy-problem-y0zhxh87.lp -solve -solu /tmp/linopy-solve-w93ybloo.sol (default strategy 1)
Option for printingOptions changed from normal to all
Presolve 40 (-3145) rows, 410 (-1151) columns and 487 (-4342) elements
Perturbing problem by 0.001% of 212.59539 - largest nonzero change 0.00017578427 ( 0.0036987348%) - largest zero change 0.00015445146
0  Obj 0 Primal inf 11285.222 (1)
48  Obj 184184.9 Primal inf 1700.1029 (24)
86  Obj 213988.73
Optimal - objective value 213988.69
After Postsolve, objective 213988.69, infeasibilities - dual 0 (0), primal 0 (0)
Optimal objective 213988.686 - 86 iterations time 0.012, Presolve 0.01
Total time (CPU seconds):       0.04   (Wallclock seconds):       0.03

[9]:

('ok', 'optimal')

Costs are 214 k€, which is much lower than the 301 k€ of the nodal market.

This is because network restrictions apart from the North/South division are not taken into account yet.

We can look at the market clearing prices of each zone:

[10]:

m.buses_t.marginal_price

[10]:

Bus	North	South
snapshot
2011-01-01 12:00:00	8.0	25.0

Build redispatch model `n`#

Next, based on the market outcome with two bidding zones m, we build a secondary redispatch market n that rectifies transmission constraints through curtailment and ramping up/down thermal generators.

First, we fix the dispatch of generators to the results from the market simulation. (For simplicity, this example disregards storage units.)

[11]:

p = m.generators_t.p / m.generators.p_nom
n.generators_t.p_min_pu = p
n.generators_t.p_max_pu = p

Then, we add generators bidding into redispatch market using the following assumptions:

All generators can reduce their dispatch to zero. This includes also curtailment of renewables.
All generators can increase their dispatch to their available/nominal capacity.
No changes to the marginal costs, i.e. reducing dispatch lowers costs.

With these settings, the 2-stage market should result in the same cost as the nodal market.

[12]:

g_up = n.generators.copy()
g_down = n.generators.copy()

g_up.index = g_up.index.map(lambda x: x + " ramp up")
g_down.index = g_down.index.map(lambda x: x + " ramp down")

up = (
    as_dense(m, "Generator", "p_max_pu") * m.generators.p_nom - m.generators_t.p
).clip(0) / m.generators.p_nom
down = -m.generators_t.p / m.generators.p_nom

up.columns = up.columns.map(lambda x: x + " ramp up")
down.columns = down.columns.map(lambda x: x + " ramp down")

n.madd("Generator", g_up.index, p_max_pu=up, **g_up.drop("p_max_pu", axis=1))

n.madd(
    "Generator",
    g_down.index,
    p_min_pu=down,
    p_max_pu=0,
    **g_down.drop(["p_max_pu", "p_min_pu"], axis=1)
);

Now, let’s solve the redispatch market:

[13]:

n.optimize(solver_name=solver)

WARNING:pypsa.components:The following transformers have zero r, which could break the linear load flow:
Index(['2', '5', '10', '12', '13', '15', '18', '20', '22', '24', '26', '30',
       '32', '37', '42', '46', '52', '56', '61', '68', '69', '74', '78', '86',
       '87', '94', '95', '96', '99', '100', '104', '105', '106', '107', '117',
       '120', '123', '124', '125', '128', '129', '138', '143', '156', '157',
       '159', '160', '165', '184', '191', '195', '201', '220', '231', '232',
       '233', '236', '247', '248', '250', '251', '252', '261', '263', '264',
       '267', '272', '279', '281', '282', '292', '303', '307', '308', '312',
       '315', '317', '322', '332', '334', '336', '338', '351', '353', '360',
       '362', '382', '384', '385', '391', '403', '404', '413', '421', '450',
       '458'],
      dtype='object', name='Transformer')
WARNING:pypsa.components:The following transformers have zero r, which could break the linear load flow:
Index(['2', '5', '10', '12', '13', '15', '18', '20', '22', '24', '26', '30',
       '32', '37', '42', '46', '52', '56', '61', '68', '69', '74', '78', '86',
       '87', '94', '95', '96', '99', '100', '104', '105', '106', '107', '117',
       '120', '123', '124', '125', '128', '129', '138', '143', '156', '157',
       '159', '160', '165', '184', '191', '195', '201', '220', '231', '232',
       '233', '236', '247', '248', '250', '251', '252', '261', '263', '264',
       '267', '272', '279', '281', '282', '292', '303', '307', '308', '312',
       '315', '317', '322', '332', '334', '336', '338', '351', '353', '360',
       '362', '382', '384', '385', '391', '403', '404', '413', '421', '450',
       '458'],
      dtype='object', name='Transformer')
INFO:linopy.model: Solve linear problem using Cbc solver
INFO:linopy.io: Writing time: 0.15s
INFO:linopy.constants: Optimization successful:
Status: ok
Termination condition: optimal
Solution: 5331 primals, 11649 duals
Objective: 3.01e+05
Solver model: not available
Solver message: Optimal - objective value 301209.38114435


INFO:pypsa.optimization.optimize:The shadow-prices of the constraints Kirchhoff-Voltage-Law were not assigned to the network.

Welcome to the CBC MILP Solver
Version: 2.10.10
Build Date: Apr 19 2023

command line - cbc -printingOptions all -import /tmp/linopy-problem-h_8jaaae.lp -solve -solu /tmp/linopy-solve-c0_x9fle.sol (default strategy 1)
Option for printingOptions changed from normal to all
Presolve 618 (-11031) rows, 1312 (-4019) columns and 4484 (-15360) elements
Perturbing problem by 0.001% of 2240.9252 - largest nonzero change 0.00099393761 ( 0.0077783838%) - largest zero change 0.0009928102
0  Obj 194178.74 Primal inf 1307911.7 (570) Dual inf 7460.2836 (158)
87  Obj -8.7416934 Primal inf 827902.14 (538)
168  Obj -8.5224694 Primal inf 954871.59 (518)
242  Obj -7.5189647 Primal inf 709539.49 (470)
327  Obj -6.6381085 Primal inf 428253.17 (414)
395  Obj -4.4328578 Primal inf 417534.09 (348)
467  Obj 3999.4114 Primal inf 188527.54 (271)
549  Obj 4034.2909 Primal inf 425628.2 (280)
634  Obj 4037.8373 Primal inf 96773.579 (158)
721  Obj 243215.9 Primal inf 3670.2052 (57)
789  Obj 301211.87
789  Obj 301209.38 Dual inf 6.4709158e-05 (4)
793  Obj 301209.38
Optimal - objective value 301209.38
After Postsolve, objective 301209.38, infeasibilities - dual 1461.2315 (99), primal 2.2101521e-05 (92)
Presolved model was optimal, full model needs cleaning up
0  Obj 301209.38 Primal inf 5.2775229e-07 (4) Dual inf 4.0000001e+08 (103)
End of values pass after 104 iterations
104  Obj 301209.38
Optimal - objective value 301209.38
Optimal objective 301209.3811 - 897 iterations time 0.092, Presolve 0.03
Total time (CPU seconds):       0.18   (Wallclock seconds):       0.17

[13]:

('ok', 'optimal')

And, as expected, the costs are the same as for the nodal market: 301 k€.

Now, we can plot both the market results of the 2 bidding zone market and the redispatch results:

[14]:

fig, axs = plt.subplots(
    1, 3, figsize=(20, 10), subplot_kw={"projection": ccrs.AlbersEqualArea()}
)

market = (
    n.generators_t.p[m.generators.index]
    .T.squeeze()
    .groupby(n.generators.bus)
    .sum()
    .div(2e4)
)
n.plot(ax=axs[0], bus_sizes=market, title="2 bidding zones market simulation")

redispatch_up = (
    n.generators_t.p.filter(like="ramp up")
    .T.squeeze()
    .groupby(n.generators.bus)
    .sum()
    .div(2e4)
)
n.plot(
    ax=axs[1], bus_sizes=redispatch_up, bus_colors="blue", title="Redispatch: ramp up"
)

redispatch_down = (
    n.generators_t.p.filter(like="ramp down")
    .T.squeeze()
    .groupby(n.generators.bus)
    .sum()
    .div(-2e4)
)
n.plot(
    ax=axs[2],
    bus_sizes=redispatch_down,
    bus_colors="red",
    title="Redispatch: ramp down / curtail",
);

/home/docs/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.25.0/lib/python3.11/site-packages/cartopy/mpl/style.py:76: UserWarning: facecolor will have no effect as it has been defined as "never".
  warnings.warn('facecolor will have no effect as it has been '

../_images/examples_scigrid-redispatch_30_1.png

We can also read out the final dispatch of each generator:

[15]:

grouper = n.generators.index.str.split(" ramp", expand=True).get_level_values(0)

n.generators_t.p.groupby(grouper, axis=1).sum().squeeze()

[15]:

1 Gas                     0.000000
1 Hard Coal               0.000000
1 Solar                  11.326192
1 Wind Onshore            1.754375
100_220kV Solar          14.913326
                           ...
98 Wind Onshore          71.451646
99_220kV Gas              0.000000
99_220kV Hard Coal        0.000000
99_220kV Solar            8.246606
99_220kV Wind Onshore     3.432939
Name: 2011-01-01 12:00:00, Length: 1423, dtype: float64

Changing bidding strategies in redispatch market#

We can also formulate other bidding strategies or compensation mechanisms for the redispatch market.

For example, that ramping up a generator is twice as expensive.

[16]:

n.generators.loc[n.generators.index.str.contains("ramp up"), "marginal_cost"] *= 2

Or that generators need to be compensated for curtailing them or ramping them down at 50% of their marginal cost.

[17]:

n.generators.loc[n.generators.index.str.contains("ramp down"), "marginal_cost"] *= -0.5

In this way, the outcome should be more expensive than the ideal nodal market:

[18]:

n.optimize(solver_name=solver)

WARNING:pypsa.components:The following transformers have zero r, which could break the linear load flow:
Index(['2', '5', '10', '12', '13', '15', '18', '20', '22', '24', '26', '30',
       '32', '37', '42', '46', '52', '56', '61', '68', '69', '74', '78', '86',
       '87', '94', '95', '96', '99', '100', '104', '105', '106', '107', '117',
       '120', '123', '124', '125', '128', '129', '138', '143', '156', '157',
       '159', '160', '165', '184', '191', '195', '201', '220', '231', '232',
       '233', '236', '247', '248', '250', '251', '252', '261', '263', '264',
       '267', '272', '279', '281', '282', '292', '303', '307', '308', '312',
       '315', '317', '322', '332', '334', '336', '338', '351', '353', '360',
       '362', '382', '384', '385', '391', '403', '404', '413', '421', '450',
       '458'],
      dtype='object', name='Transformer')
WARNING:pypsa.components:The following transformers have zero r, which could break the linear load flow:
Index(['2', '5', '10', '12', '13', '15', '18', '20', '22', '24', '26', '30',
       '32', '37', '42', '46', '52', '56', '61', '68', '69', '74', '78', '86',
       '87', '94', '95', '96', '99', '100', '104', '105', '106', '107', '117',
       '120', '123', '124', '125', '128', '129', '138', '143', '156', '157',
       '159', '160', '165', '184', '191', '195', '201', '220', '231', '232',
       '233', '236', '247', '248', '250', '251', '252', '261', '263', '264',
       '267', '272', '279', '281', '282', '292', '303', '307', '308', '312',
       '315', '317', '322', '332', '334', '336', '338', '351', '353', '360',
       '362', '382', '384', '385', '391', '403', '404', '413', '421', '450',
       '458'],
      dtype='object', name='Transformer')
INFO:linopy.model: Solve linear problem using Cbc solver
INFO:linopy.io: Writing time: 0.15s
INFO:linopy.constants: Optimization successful:
Status: ok
Termination condition: optimal
Solution: 5331 primals, 11649 duals
Objective: 4.79e+05
Solver model: not available
Solver message: Optimal - objective value 479003.12190570

Welcome to the CBC MILP Solver
Version: 2.10.10
Build Date: Apr 19 2023

command line - cbc -printingOptions all -import /tmp/linopy-problem-92mjz4in.lp -solve -solu /tmp/linopy-solve-fjllz0d5.sol (default strategy 1)
Option for printingOptions changed from normal to all
Presolve 618 (-11031) rows, 1332 (-3999) columns and 4504 (-15340) elements
Perturbing problem by 0.001% of 4481.8503 - largest nonzero change 0.00052409114 ( 0.0022575759%) - largest zero change 0.00046871519
0  Obj 223878.1 Primal inf 1307911.7 (570)
87  Obj 223878.39 Primal inf 894699.13 (538)
171  Obj 223878.77 Primal inf 671646.59 (510)
244  Obj 223879.27 Primal inf 638917.69 (477)
313  Obj 223881.58 Primal inf 566786.51 (435)
386  Obj 223883.88 Primal inf 324277.76 (353)
471  Obj 231340.92 Primal inf 260580.73 (312)
543  Obj 231344.09 Primal inf 21676789 (404)
620  Obj 232503.63 Primal inf 195077.94 (218)
701  Obj 234673.18 Primal inf 1243404.2 (79)
788  Obj 473210.98 Primal inf 283.79626 (26)
820  Obj 479005.69
820  Obj 479003.13 Dual inf 0.00060195436 (20)
829  Obj 479003.12
Optimal - objective value 479003.12
After Postsolve, objective 479003.12, infeasibilities - dual 2801.8264 (91), primal 1.9571595e-05 (85)
Presolved model was optimal, full model needs cleaning up
0  Obj 479003.12 Primal inf 9.2850222e-07 (6) Dual inf 6.0000003e+08 (97)
End of values pass after 97 iterations
97  Obj 479003.12
Optimal - objective value 479003.12
Optimal objective 479003.1219 - 926 iterations time 0.112, Presolve 0.03
Total time (CPU seconds):       0.20   (Wallclock seconds):       0.18

INFO:pypsa.optimization.optimize:The shadow-prices of the constraints Kirchhoff-Voltage-Law were not assigned to the network.

[18]:

('ok', 'optimal')

Costs are now 502 k€ compared to 301 k€.

Redispatch Example with SciGRID network

Contents

Redispatch Example with SciGRID network#

Load example network#

Solve original nodal market model o#

Build market model m with two bidding zones#

Build redispatch model n#

Changing bidding strategies in redispatch market#

Solve original nodal market model `o`#

Build market model `m` with two bidding zones#

Build redispatch model `n`#